heat-timer Mini-MOD-CNC User manual

HT# 059102-00 B




ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
Extension Module
Full Modulation Sequencing Extension
F
H
J
Power
CAUTION: Risk of Electric Shock.
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PWR
L N
1 2
E
3 4
F
5 6
G
7 8
H
9 10
I
11 12
EXTENSION
MODULE
RS-485
Ext A
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
E
G
I
Comm
Ext B
K
M
O
L
N
P
1716
VLTmA
CUR / VLT
201916
VLTmAGND
CUR / VLT
232219
VLTmAGND
CUR / VLT
262522
VLTmAGND
CUR / VLT
J
13 14
K M OL N P
E F G H
K ML N
15
GND
18
GND
21
GND
24
GND
2928
VLTmA
CUR / VLT
323116
VLTmAGND
CUR / VLT
27
GND
30
GND
I J
O P
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
RUNPROGRAM
12 13 15
14 17
16 18 22
20
19 21 24
23
-+
+
mA
GND VLT
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
OD=25oF SYS= 145oF
<<A>> B <C> D
100% 52% --- ---
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
29 25 27
26 28 32
30 31
TT
OO
TEMP
OUTDOOR
OO
TEMP
SYSTEM
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
12345678910 11
LN
RS-485
SYS ABCD
PWR
EXTENSION
MODULE
Mini-MOD-CNC







2 Heat-Timer Corp.

 . . . . . . . . . . . 3
 . . . . . . . . . . . . .4
 . . . . . . . . . . . . . 5
Features . . . . . . . . . . . . . . . . . . . . .6
Outdoor Reset Concept . . . . . . . . . . . . . 7
Reset Ratio/Outdoor Reset . . . . . . . . . . . . 7
Make Sure You Have the Right Control . . . . .8
 . . . . . . . . . . . . . . . . . . .8
Selecting the System Features. . . . . . . . . . 8
 . . . . . . . . . . . . . . . . . . . . 9
Mounting the Enclosure . . . . . . . . . . . . . 9
Install the Sensors . . . . . . . . . . . . . . . 10
System Sensor (HSS) Installation . . . . . . . . 10
Outdoor Sensor Installation . . . . . . . . . . . 10
Wiring . . . . . . . . . . . . . . . . . . . . . 11
Wiring the Power. . . . . . . . . . . . . . . . 11
Wiring the Sensors . . . . . . . . . . . . . . . 11
Wiring the Shutdown, Tstat, or Setback . . . . . 11
Wiring the Prove . . . . . . . . . . . . . . . . 12
Wiring the Domestic Hot Water (DHW) Call . . . 12
Wiring the System Output . . . . . . . . . . . 12
Wiring the Boilers . . . . . . . . . . . . . . . 13
Wiring Multi-Stage Boiler Outputs . . . . . . . . 13
Wiring to Modulating Output . . . . . . . . . . 13
Connecting to the Mini-Extension Panels . . . . 14
Connecting to the 4-20mA EMS Interface . . . . 14
 . . . . . . . . . . . 15
Startup Settings . . . . . . . . . . . . . . . . 16
Program Change Switch Setting . . . . . . . . 16
Startup Sequence . . . . . . . . . . . . . . . 16
Sensor Type . . . . . . . . . . . . . . . . . . 16
Switch Set Point . . . . . . . . . . . . . . . . 16
Switch Differential . . . . . . . . . . . . . . . 17
Switch Delay. . . . . . . . . . . . . . . . . . 17
Heavy Load Sequence 2nd Group . . . . . . . 17
Condensing Boiler Type . . . . . . . . . . . . 17
Condensing and Non-Condensing Boiler Number 17
Modulating Boiler Settings . . . . . . . . . . . 18
Modulating Output Type . . . . . . . . . . . . 18
Modulating Mode. . . . . . . . . . . . . . . . 18
Sequencing Boiler Settings . . . . . . . . . . 19
Sequencing Output Type . . . . . . . . . . . . 19
Staging Mode . . . . . . . . . . . . . . . . . 19
Prove/Domestic Hot Water (DHW) Priority . . . . 19
Domestic Hot Water Set Point . . . . . . . . . 19
Shutdown/Tstat/Setback Mode . . . . . . . . . 19
Boost Mode . . . . . . . . . . . . . . . . . . 20
Sensor Fault . . . . . . . . . . . . . . . . . . 20
Setting the Control to Factory Defaults. . . . . 20
 . . . . . . . . . 21
Operating Settings . . . . . . . . . . . . . . . 22
Program Change Switch Setting . . . . . . . . 22
Season . . . . . . . . . . . . . . . . . . . . 22
Reset Ratio . . . . . . . . . . . . . . . . . . 22
Offset . . . . . . . . . . . . . . . . . . . . . 22
Outdoor Cutoff Temperature . . . . . . . . . . 23
Minimum Water Temp . . . . . . . . . . . . . 23
Maximum Water Temp . . . . . . . . . . . . . 23
System Settings . . . . . . . . . . . . . . . . 24
Setback . . . . . . . . . . . . . . . . . . . . 24
Purge Delay . . . . . . . . . . . . . . . . . . 24
System Run-On . . . . . . . . . . . . . . . . 24
Lead Boiler Rotation . . . . . . . . . . . . . . 25
Standby Time . . . . . . . . . . . . . . . . . 25
Last Stage Hold . . . . . . . . . . . . . . . . 25
Lead Stages . . . . . . . . . . . . . . . . . . 25
Operating Modulating Boiler Settings . . . . . 26
Gain. . . . . . . . . . . . . . . . . . . . . . 26
Lag Delay . . . . . . . . . . . . . . . . . . . 26
Soft-Off Delay . . . . . . . . . . . . . . . . . 26
Operating Staging Boiler Settings . . . . . . . 27
Reaction Time . . . . . . . . . . . . . . . . . 27
Minimum Runtime . . . . . . . . . . . . . . . 27
Day / Night Schedule. . . . . . . . . . . . . . 28
Set Time. . . . . . . . . . . . . . . . . . . . 28
History . . . . . . . . . . . . . . . . . . . . . 28
Maintenance . . . . . . . . . . . . . . . . . . 28
System & Outdoor Sensor Trim . . . . . . . . . 29
Output Modulation Trim. . . . . . . . . . . . . 29
Conguration . . . . . . . . . . . . . . . . . 29
Display . . . . . . . . . . . . . . . . . . . . 30
Boiler Status . . . . . . . . . . . . . . . . . . 30
Display Sequencing Boiler Status . . . . . . . . 30
Display Messages . . . . . . . . . . . . . . . 30
Boiler Stage Settings . . . . . . . . . . . . . . 31
Mode . . . . . . . . . . . . . . . . . . . . . 31
Ignition % . . . . . . . . . . . . . . . . . . . 32
Modulation Start % . . . . . . . . . . . . . . . 32
Copy Settings - Boiler A Only . . . . . . . . . . 32
. . . . . . . . . . . . . . . . 33
 . . . . . . . 34
 . . . . . . . 35
 . . . . . . . . . . . . . . . . . . . . 36
 . . . . . . . . . . . . . . . . . . . . . . 37
 . . . . . . . . . . . . . . . . . 40
HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 3

In response to new advancement in condensing boiler design and size, many applications utilize multiple condensing boilers in
addition to the non-condensing boilers. That triggered Heat-Timer's patent design of the Mini-MOD-CNC . It is intended to manage
the two groups of boilers to maximize system efciency at the lowest operating cost while maintaining the desired comfort. The
Mini-MOD-CNC operates each group based on the Target temperature switching set point.
Depending on the actual Target Temperature, the Mini-MOD-CNC will determine which group of boilers will be the lead and which
group will be the lag group. The Condensing Group of boilers will be the Lead group when the Target Temperature is below the
Switching Set Point. However, when the Target Temperature rises above the Switching Set Point, the Non-Condensing Boiler Group
will be the lead group and the Condensing Group will be the lag group.
Basically, the Mini-MOD-CNC will allow the condensing group of boilers to operate as along as the Target Temperature is below the
Switching Set Point. See "Switch Set Point" on page 16. During that period, if additional output boilers are needed, the Mini-MOD-
CNC will energize the non-condensing boilers to meet the load. See "Heavy Load Sequence 2nd Group" on page 17. When less output
is required the Mini-MOD-CNC will de-energize the non-condensing boilers prior to de-energizing the condensing boilers.
Above the Switch Set Point
Non-Condensing are the Lead Group
Condensing are the Lag Group
Target Switch
Set Point = 120°F
Below the Switch Set Point
Condensing are the Lead Group
Non-Condensing are the Lag Group
120°F
140°F
100°F
SWITCH MODE = Target Temperature
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 910 1112 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
CONDCOND
NON-
COND
NON-
COND
NON-
COND
NON-
COND
CONDCOND
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 910 1112 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Target
Temp
Above the Switch Set Point
Condensing are the Lead Group
Non-Condensing are the Lag Group
Outdoor Switch
Set Point = 30°F
Below the Switch Set Point
Non-Condensing are the Lead Group
Condensing are the Lag Group
30°F
50°F
10°F
SWITCH MODE = Outdoor Temperature
CONDCOND
NON-
COND
NON-
COND
NON-
COND
NON-
COND
CONDCOND
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 910 1112 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 910 1112 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Outdoor
Temp
HT# 059102-00 B

4 Heat-Timer Corp.

HT# 059102-00 B
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
RUNPROGRAM
12 13 15
14 17
16 18 22
20
19 21 24
23
-+
+
mA
GND VLT
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
OD=25oF SYS= 145oF
<<A>> B <C> D
100% 52% --- ---
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
29 25 27
26 28 32
30 31
TT
OO
TEMP
OUTDOOR
OO
TEMP
SYSTEM
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
12345678910 11
LN
RS-485
SYS ABCD
PWR
EXTENSION
MODULE
Mini-MOD-CNC
The digital display shows the System and Outdoor temperatures,
the lead stage and lead group <<in brackets>>, and the status of
each stage. To view and adjust settings, press the appropriate buttons.
120VAC Power
Four N.O. Boiler startup relay
outputs. Each is wired in series
with each boiler's limit circuit.
System Output controls
pumps, valves, or other
system components.
Four modulation outputs can be 0-5V,
0-10V, 1-5V, 2-10V, or 4-20ma. Go to
Startup Menu to determine the type of
output for each stage.
LED indicates the
associated relay status.
Button functions are presented on
Bottom Row of display.
When connecting Outdoor and System
Sensors, no Polarity is observed.
Prove terminals must be connected for
the Mini-Mod-CNC to operate the boilers.
Connect Extension panels to
add additional stages using
a phone style cable (cable
provided with Mini-Extension).
Program Switch to restrict access to
function changes. This switch is
covered with the Wiring Enclosure.

Mini-MOD-CNC & Mini-Extension Installation Manual 5

HT# 059102-00 B
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
Extension Module
Full Modulation Sequencing Extension
F
H
J
Power
CAUTION: Risk of Electric Shock.
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PWR
L N
1 2
E
3 4
F
5 6
G
7 8
H
9 10
I
11 12
EXTENSION
MODULE
RS-485
Ext A
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
E
G
I
Comm
Ext B
K
M
O
L
N
P
1716
VLTmA
CUR / VLT
201916
VLTmAGND
CUR / VLT
232219
VLTmAGND
CUR / VLT
262522
VLTmAGND
CUR / VLT
J
13 14
K M OL N P
E F G H
K ML N
15
GND
18
GND
21
GND
24
GND
2928
VLTmA
CUR / VLT
323116
VLTmAGND
CUR / VLT
27
GND
30
GND
I J
O P
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
120VAC Power
Six N.O. Boiler startup relay
outputs. Each is wired in series
with the boiler's limit circuit.
Six modulating outputs can be 0-5V,
0-10V, 1-5V, 2-10V, or 4-20ma. Go to
Mini-MOD or Mini-MOD-CNC Startup Menu
to determine the type of output for each stage.
LED indicates the
associated relay status.
Connect to Mini-MOD or Mini-MOD-CNC
and additional Extension panels to add
additional stages using phone style cable
(cable provided with Mini-Extension).
Extension Selection Switch to determine
Stage letters and LED colors.
Ext-A Stages E - J and all LEDs are Green
Ext-B Stages K - P and all LEDs are Red
This switch is covered with the Wiring Enclosure.

6 Heat-Timer Corp.


The Mini-MOD-CNC can operate both modulating and staging boilers. Just specify each of the Condensing and Non-Condensing Boiler
Group type and the Mini-MOD-CNC will activate the groups based on an adjustable set of criteria.

The Mini-MOD-CNC's control algorithms allow it to look at the rate of change in the system. If the system temperature is changing
quickly, the Mini-MOD-CNC will react quickly to adjust the modulating stages’ output. If the system temperature changes slowly, the
Mini-MOD-CNC will make slow and gradual output adjustments. Therefore, the Mini-MOD-CNC adapts to specic system requirements
and minimizes uctuations around the set point.

Whenever any of the Condensing or Non-Condensing Boiler Group type is set to Modulating, the Mini-MOD-CNC will accurately control
the output from 0 to 100% of modulation for each of these different types of motors. Moreover, a single Mini-MOD-CNC can control
multiple modulating burners each with a different modulating signal.

Whenever one of the Condensing or Non-Condensing Boiler Group Type is set to Staging, the Mini-MOD-CNC will accurately sequence
the stages using a PID logic. The sequencing group will have a set of adjustable parameters to help achieve better operation.

The Mini-MOD-CNC’s alphanumeric digital display names each system parameter in simple English and shows its precise value. The
easy to follow menu system allows users to quickly make changes to any system setting without having to learn any specialized codes
or keyboard commands.

Rotating the lead stage of each group promotes even wear. The Mini-MOD-CNC has three modes of rotation: Manual, Last On, or Time.
The Time rotates the lead stage every selected time period from every hour to every 60 days.

The Mini-MOD-CNC has a hydronic outdoor temperature reset function. This allows the Mini-MOD-CNC to change the set point
based on outdoor temperature. Furthermore, additional settings have been added to ne tune this operation, like Offset, Minimum, and
Maximum Water Temperature and night setback schedule.

This output can be used to activate a system pump, combustion air damper, or perform any other function that is required when any stage
is active. It will energize whenever the outdoor temperature is below the Outdoor Cutoff setting. A System Prove input checks the status
of components activated by the System output before stages can be activated.

The Mini-MOD-CNC can stage modulating boilers as needed. In Normal Modulation, it will allow the modulation to increase on the lead
boiler until it reaches its modulation start point adjustment. Then, the Mini-MOD-CNC will start the next boiler and so on. Moreover,
the Mini-MOD-CNC allows for a parallel mode that can modulate several boilers together as a one large boiler. This mode is useful when
used with condensing boilers as they run more efcient at lower modulation. Thus, it is better to run several boilers at lower modulation
than to run a single boiler at full re.

As a stand-alone, the Mini-MOD-CNC is designed to control four stages. However, it has the capability of expanding its control to two
extension panels (HT# 926712-00) each with six boiler stages. Thus, the Mini-MOD-CNC can control a total of up to 16 boiler stages.
HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 7

The Mini-MOD-CNC has multiple operating modes that satisfy most hydronic systems.
It changes the System Set Point based on outdoor temperature (Outdoor Reset). The
Mini-MOD-CNC varies the temperature of the circulating heating water in response to
changes in the outdoor temperature. The heating water temperature is controlled through the
modulation or sequencing of the stages.
The Mini-MOD-CNC also controls the system circulating pump with an adjustable Outdoor
Cutoff. When the outdoor temperature is above the Outdoor Cutoff, the pump is off and no
heating water is circulated through the system. When the outdoor temperature drops below
the Outdoor Cutoff, the system pump relay is activated and the heating water circulates
through the system. The temperature of the heating water is controlled by the Reset Ratio,
Water Offset, and changes with Outdoor temperature.

When a building is being heated, heat escapes through the walls, doors, and windows to
the colder outside air. The colder the outside temperature, the more heat escapes. If you
can input heat into the building at the same rate that it is lost out of the building, then the
building temperatures will remain constant. The Reset Ratio is an adjustment that
lets you achieve this equilibrium between heat input and heat loss.
The starting point for most systems is the 1.00 (OD):1.00 (SYS) (Outdoor
Temperature : Heating Water Temperature) ratio. This means that for every
degree the outdoor temperature drops, the temperature of the heating water will
increase one degree. The starting point of the curve is adjustable, but comes
factory selected at 70°F Outdoor Temp. and 100°F Water Temp. For example with
a 1.00 (OD):1.00 (SYS) ratio, if the outdoor temperature is 50°F, this means the
temperature has fallen 20° from the starting point of 70°F. Therefore, the heating
water temperature will increase 20° to 120°F.
Each building has different heat loss characteristics. A very well insulated
building will not lose much heat to the outside air, and may need a Reset Ratio
of 2.00 (OD):1.00 (SYS) (Outdoor:Water). This means the outdoor temperature
would have to drop 2 degrees to increase the water temperature 1 degree. On
the other hand, a poorly insulated building with insufcient radiation may need
a Reset Ratio of 1.00 (OD):2.00 (SYS). This means that for each degree the
outdoor temperature dropped the water temperature will increase 2 degrees. The
Mini-MOD-CNC has a full range of Reset Ratios to match any buildings heat loss
characteristics.
A heating curve that relies not only on Outdoor temperature but also on the type of
radiation will improve heat comfort. The following are suggested initial settings
for different types of radiation based on average building insulation and heat loss.
The contractor can ne tune these adjustments based on the specic building need.
  
Radiators (Steel & Cast Iron) 1.00 (OD) : 1.00 (SYS) 0˚F
Baseboard (Finned copper tube& Cast Iron) 1.00 (OD) : 1.00 (SYS) 0˚F
Radiant (High Mass/Concrete) 4.00 (OD) : 1.00 (SYS) -10˚F
Radiant (Low Mass/Joists) 2.00 (OD) : 1.00 (SYS) -10˚F
Fan Coils & Air Handlers 1.00 (OD) : 1.00 (SYS) 20˚F
Outdoor Temperature
Water Temperature
70 405060
130
120
110
100
Outdoor Temperature
Water Temperature
70 405060
110
100
90
80
Outdoor Temperature
Water Temperature
70 405060
150
140
130
120
1:4
With a 0° Offset, the
Reset curves begin at
100° Water Temperature.
With a -20° Offset, the
Reset curves begin at
80° Water Temperature.
With a +20° Offset, the
Reset curves begin at
120° Water Temperature.
1:4
1:4 1:1
1:1
1:1
4:1
4:1
4:1
90
100
+20 Offset
-20 Offset
Outdoor Temperature
Water Temperature
70 405060
130
120
110
100
1:4 1:1
4:1
Colder
Warmer
Outdoor Temperature (in °F)
70 60 50 40 20
30 0 -10
10 -20
100
120
110
130
140
150
160
180
170
190
200
210
220
1:3 1:2 1:1.5
1:1.25
1:1
1.25:1
1.5:1
2:1
3:1
4:1
Water Temperature (in °F)
Reset Ratio Curves
Reset Ratio is Presented as
Outdoor Temp. : Water Temp. Ratio
1:4
HT# 059102-00 B

8 Heat-Timer Corp.

If you need the Mini-MOD-CNC to do additional tasks that either are not listed or do not know how to congure them, contact Heat-
Timer Corp. Sales Department either by Phone [phone], Fax [phone], or by E-mail [e-mail].

Setting an Initial Program will ease the conguration of the Mini-MOD-CNC and will give the opportunity to utilize many of the energy
saving features and give more comfortable heat when needed.
The program should consist of the following:
• Selecting the features that your system can utilize.
• Installation: Install the Control, switches and sensors. See "Installation" on page 9
• Setting the System Startup. See "Startup Settings" on page 16
• Setting the System Operating Settings. See "Operating Settings" on page 22
• Setting the Stages. See "Operating Modulating Boiler Settings" on page 26 and "Operating Staging Boiler Settings" on page 27
• Adjusting Reset Ratio and Water Offset (In Reset Mode Only). See "Reset Ratio" on page 22

The Mini-MOD-CNC has been designed with Hydronic building heating, using both condensing and non-condensing boilers, as the
primary purpose. With this in mind, many of the Mini-MOD-CNC features can be utilized to ease, enhance, and improve your system
performance. Some of these features are listed in this section.

• The Mini-MOD-CNC can be congured to control up to 4 condensing and non-condensing boilers. It can control up to 16 boiler
stages using a maximum of two Mini-Extension Panels (HT# 926712-00).

• The Mini-MOD-CNC can stage modulating boilers using one of two methods. Normal Modulation Mode, allows it to increase the
modulation of the lead boiler. When the lead boiler reaches its Modulation Start point adjustment and does not satisfy the load, the
Mini-MOD-CNC will start the next boiler and so on. This mode targets boilers that can run more efcient at higher modulation rates.
• The Parallel Modulation Mode can modulate several boilers together as one large boiler. This mode is useful for boilers that are
more efcient at lower ring rate as in many condensing boilers.

• The Mini-MOD-CNC is designed to accurately control the modulation output from 0 to 100% for either current (4-20mA) or voltage
(0-5V, 0-1V, 1-5V, 2-10V) motors. A single Mini-MOD-CNC can control a combination of the above modulation motors.

• Rotating the rst burner to be activated on a call for output promotes even wear on all burners. The Mini-MOD-CNC has three modes
of rotation: Manual, Last-ON, or Time; automatically rotating every selected time period from every hour to every 60 days.

Two Setback modes are available for the Mini-MOD-CNC:
• The Day/Night Scheduling provides an adjustable time-based schedule for the Setback (only available when Shutdown or Tstat is
selected as the Setback/Shutdown Startup option). See "Shutdown/Tstat/Setback Mode" on page 19.
• The Setback mode uses an external signal to switch the operation of the Mini-MOD-CNC in and out of setback mode.

• This feature lets the Mini-MOD-CNC run the SYS relay for a longer period after the boilers have been turned off. When this relay is
used to control a pump, it helps in dissipating the excess heat from the boilers combustion chamber.
HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 9

Each of the Mini-MOD-CNC or Mini-Extension consists of three primary enclosure components.
• TheEnclosureDisplayModule: contains the display, buttons, LEDs and electric wiring terminals. It has two screws to hold it to
the base. A program conguration switch, used to adjust Mini-MOD-CNC settings, is placed above the terminals. This switch is
enclosed with the enclosure wiring cover for security. Wiring terminals are of the plug-in type to ease installation and removal.
• TheEnclosureBase: contains the holes to mount and hold the control against the wall or any at surface. All other enclosure
components mount on the base. The bottom section of the Enclosure Base contains the wiring chamber with knockouts on the
bottom to ease installation.
• TheEnclosureWiringCover: seals the wires from the external environment. It has two screws to hold it the base and a hole to
secure a lock on the wiring enclosure. A plastic web that separates the wiring chamber into high and low volt sections has been
provided.

• Select a location near the equipment to be controlled.
• The surface should be at and sufciently wide and strong to hold the Mini-MOD-CNC or the Mini-Extension.
• Keep the control away from extreme heat, cold, or humidity. Ambient operating temperature is from 20 to 120°F.
• Remove the Enclosure Wiring Cover from the control enclosure by removing the two bottom screws.
• Remove the Enclosure Display Module by removing the enclosure middle screws.
• Screw the Enclosure Base to the surface through the upper and lower mounting holes on the back of the enclosure.
• Replace the Enclosure Display Module and replace the enclosure middle screws.
• Do not replace the enclosure wiring cover until all wiring is done.
• When purchasing a padlock for the enclosure, the maximum shank diameter should not exceed ¼"
Enclosure Display Module
Enclosure Wiring Cover Enclosure Base
Hole for optional lock
(not supplied)
Mounting Holes
Display Mounting Screws
Wiring Cover
Mounting Screws
HT# 059102-00 B

10 Heat-Timer Corp.


• Only use a Standard Brass Tube sensor (HT #904250-00).
• The sensor wires can be extended up to 500' using a shielded 2-conductor cable
(Belden #8760 or equivalent). Do not ground the shield at the sensor but at the
panel using one of the terminals marked with an “O”.
• Do not run sensor wires in conduit with line voltage wiring.
• Install a 3/8"ID 1/2"NPT immersion well (HT #904011-00 or equivalent).
• Insert the sensor in a well approximately 10' feet past the last boiler on the
common supply header but before any major takeoffs.
• The sensor must be located where it sees the output of all the boiler stages. If
a boiler is piped so that the sensor does not see its output, the Mini-MOD-CNC
will not sequence the boilers correctly.
• The sensor can also be installed on the return to the boilers after all major returns
and before any boiler. However, when setting the reset ratio and the offset, the
user must consider the temperature drop across the building loop.
Immersion Well
3/8" ID 1/2" NPT
Heating System
Sensor
Common Supply Pipe
Sensor Probe
Immersion Heating System Sensor
Shield
Common Supply Pipe
Sensor Probe
Strap-On Heating System Sensor
Shield
Pipe Insulation
Connect
To control

If the System Sensor can not sense the
correct water temperature, the Mini-
MOD-CNC will not provide comfortable
heat levels.

• Only use the Heat-Timer sensor included with the unit (HT# 904220-00) .
• Locate the sensor in the shade on the north side of the building. The sensor
should never be in direct sunlight.
• Be sure the location is away from doors, windows, exhaust fans, vents, or other
possible heat sources.
• The sensor should be mounted approximately 10' feet above ground level.
• Adhere the Outdoor Label provided to the back of the sensor base.
• Use the Enclosure Base bottom knockout for the conduit. Use the locknut to hold
the conduit and enclosure base together. Screw the cover to the base.
• If screws are used to afx the enclosure to the wall, make sure to seal around the
sensor and wall except from the bottom.
• The sensor wires can be extended up to 500' using shielded 2-conductor cable
(#18/2). Do not ground the shield at the sensor but at the control using the
terminal marked with an “O”.
• Do not run sensor wires in conduit with line voltage wiring.




System Sensor
In Well
Shield
Not connected
Well Locknut
Sensor
in Well
Well
Sensor 2-Conductor
Shielded Cable
System
Strap-On
Sensor
Shield
Not connected
Plastic
Tie-Wraps
Around Pipe
Outdoor
Sensor
snap-in
location
Shield
not connected
Conduit
Outdoor Label
on back of Sensor
Outdoor Sensor
Strap-On Sensor
Immersion Sensor
Mounting
screws
location
Seal around
sensor and wall
Outdoor
drip-hole
HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 11

• All wiring must enter the enclosure through the bottom knockouts.
• Class 1 voltage wiring must utilize a different knockout and conduit from any Class 2 voltage wiring.


• Bring the 120VAC 60Hz power wires through the bottom left knockout of the enclosure.
• Connect the hot line to terminal marked L.
• Connect the neutral line to the terminal marked N.
• Heat-Timer recommends installing a surge suppressor on the power source to the Mini-MOD-CNC.



SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
Line
Neutral
120VAC
Power Source





• A Mini-MOD-CNC must be connected to a System temperature sensor (HT #904250-00 provided) located in the
common header. The sensor must be inserted in a 3/8 ID well (HT #904011-00 or equivalent).
• Temperature sensor wires can be extended up to 500’ by splicing its wires with a shielded 2-conductor cable
(Belden #8760 or equivalent (#18/2)).
• Temperature sensors have no polarity. Connect the two wires from the sensor to the Mini-MOD-CNC terminals
marked SYSTEM TEMP 27, 28.
• Connect the sensor shield to the circled terminal 28 with one of the sensor wires.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23
29
25
27
26 28
32
30
31
LN
-+
+
T
T
OO
RS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
System Sensor
Sensor Shield
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28
32
30 31
LN
-+
+
TT
OO
RS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
Outdoor Sensor
Sensor Shield


• The Mini-MOD-CNC will vary the system Set Point based on outdoor temperature. In addition, the outdoor sensor
is used as an Outdoor Cutoff. The Mini-MOD-CNC will disable all boilers when the outdoor temperature is above
the adjustable Outdoor Cutoff temperature.
• For an outdoor sensor use the outdoor sensor provided (HT #904220-00).
• The sensor wires can be extended up to 500’ using shielded 2-conductor cable (Belden #8760 or equivalent (#18/2)).
• Temperature sensors have no polarity. Connect the wires from the outdoor sensor to the Mini-MOD-CNC terminals
marked OUTDOOR TEMP - 25, 26.
• Connect the shield to the circled terminal 26 with one of the sensor wires.


• The Shutdown will be available when selected as the Shutdown/Tstat/Setback mode from the Startup menu. See
"Shutdown/Tstat/Setback Mode" on page 19. This will provide the user with an adjustable Day/Night Schedule. See
"Day/Night Schedules" on page 28.
• The Shutdown feature can be used whenever it is desirable to turn off the Mini-MOD-CNC stage outputs from a
remote location or another controller (i.e. EMS input).
• The Tstat option, when selected from the Shutdown/Tstat/Setback startup menu, offer the capability of controlling
the operation of the Mini-MOD-CNC based on a thermostat input. This will provide the user with an adjustable
Day/Night Schedule.
• The thermostat will send the Mini-MOD-CNC a call for heat by shorting terminals 31 and 32.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28
32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
Shutdown,
T-Stat, or
Setback Signal
HT# 059102-00 B

12 Heat-Timer Corp.
• When the Shutdown input is enabled by closing the dry contact, or when the Tstat input is disabled by opening the dry-contact, all
active modulating boilers will immediately modulate down to low for the Soft-Off period, then turn off. All staging boilers will
turn off immediately.
• The System Output relay will remain active until the System Run-On Delay expires and then it will turn off.
• When Setback is selected in the Startup, a BMS/EMS or external clock can provide a Setback signal using these input terminals.
See "Shutdown/Tstat/Setback Mode" on page 19. No Day/Night Schedule will be available when Setback is selected from the
Shutdown/Tstat/Setback mode in the Startup menu.
• The signal must be a dry contact only. No voltage can be placed across the SHUTDOWN/TSTAT/SETBACK terminals.
• Bring the two wires from the dry contact to the terminals marked SHUTDOWN/TSTAT/SETBACK- 31,32.


• The Prove feature is provided to check system component operation and must be selected in the Startup Menu
from the Prove/DHW Sharing menu. See "Prove/Domestic Hot Water (DHW) Priority" on page 19.
• A typical use of this feature is to check for pump ow or combustion air damper status before ring any boiler.
• If the PROVE input is open on a call for heat, the Mini-MOD-CNC will enable only the System Output. All boiler
outputs will be off when the PROVE input is open.
• A factory-installed jumper provides the System Prove signal. Do not remove the jumper unless it will be replaced
by a System Prove signal or these terminals are to be used for DHW call input.
• Bring the two wires from the dry contact to the terminals marked PROVE - 29, 30. No voltage can be placed
across the PROVE terminals
• Prove Input terminals can accept a dry-contact signal only. No voltage can be placed across these terminals.

The PROVE input cannot be used as a safety limit. All equipment must have its own
certied limit and safety controls as required by local codes. If Prove is selected in the
startup menu, no boiler stage will start unless Prove terminals are shorted. DO NOT
remove the PROVE jumper supplied unless replacing it with a Prove signal.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23
29
25 27
26
28 32
30 31
LN
-+
+
TT
O
O
RS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
Prove Signal
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23
29
25 27
26
28 32
30 31
LN
-+
+
TT
O
O
RS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
DHW Signal


• DHW can be used to raise system Set Point to the DHW Set Point as well as manage the System Pump according
to the DHW Priority setting. One of the DHW options must be selected from the Prove/DHW Sharing Startup
menu. See "Prove/Domestic Hot Water (DHW) Priority" on page 19.
• Wire an aquastat or a control to provide dry-contact closure on the DHW Call terminals.
• Remove the jumper on the DHW terminals for proper operation.
• DHW Call terminals can accept dry contact signals only. No voltage can be placed across these terminals.


• The SYS output relay will energize whenever the outdoor temperature is below the Outdoor Cutoff.
• The SYS relay will remain constantly energized while the outdoor temperature is below the Outdoor Cutoff.
• When the outdoor temperature rises 2°F above the Outdoor Cutoff, the SYS output will remain energized for the
period set by the System Run-On. See "System Run-On" on page 24.
• In addition, the System output will energize during summer DHW calls when DHW No Priority is selected. See
"Prove/Domestic Hot Water (DHW) Priority" on page 19.
• The SYS output has one Normally Open (N.O.) relay contact rated for (1/8HP).
• The N.O. contacts are dry contacts only. They do not source any voltage.
• Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
3456
78910 11 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS A
BCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
System Pump
or Pump Starter
L
N
HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 13

• When wiring condensing and non-condensing boilers make sure that condensing boilers utilize the rst stages
and non-condensing boilers will utilize the following stages. That is, if the installation had two condensing
modulating boilers and two non-condensing staging On/Off boilers, Stage A and B will be used by the condensing
boilers while C and D will be used by the non-condensing boilers.


• Each boiler output (A through D) has one Normally Open (N.O.) relay contact.
• The N.O. contacts are dry contacts only. They do not source any voltage.
• Wire the N.O. relay contacts in series with the unit’s limit circuit.
• Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.
• Note that some modulating boilers may not require the use of these outputs.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678
910 11 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS AB
CD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
Boiler Enable
Output
Boiler


• Each stage output (A through D) has one Normally Open (N.O.) relay
contact that does not source any power.
• Wire each of the N.O. relay contacts to its respective boiler stage.
Note that on the display of the Mini-MOD-CNC each staging boiler
will consist of multiple letters. The letters represent outputs that
should be wired to that boiler. The rst letter should be wired to the
lowest ring stage and the next letter to the next stage and so on. See
"Boiler Status" on page 30.
• Class 1 voltages must enter the enclosure through a different opening
from any Class 2 voltage wiring.
OD=55oF SYS=142oF
<CD> EF
LO ---
STAGE ◄ ► MENU
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567
8910 11 12
13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS AB
CD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
2-Stage Boiler
Stage1
Stage2

The Mini-MOD-CNC can modulate any combination of the following boiler signals. The Modulating Output Type
must be selected properly before connecting any output wires to avoid damaging components. See "Modulating
Output Type" on page 18. Some modulating boilers may require the use of the relay stage outputs. See "Wiring the
Boilers"


• The Mini-MOD-CNC can operate up to four 4-20 mA modulating motors.
• The Mini-Extension can operate up to six 4-20 mA modulating motors.
• The Mini-MOD-CNC and the Mini-Extension sources 24VDC excitation voltage for the 4-20mA signal.
• Wire the (-) from the modulating motor to the boiler terminal on the Mini-MOD-CNC marked (GND). That is for
boiler A, the modulating (-) terminal will be 13.
• Wire the (+) from the modulating motor to the boiler terminal on the Mini-MOD-CNC marked (mA). That is for
boiler A, the modulating (-) terminal will be 14.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12
13 15
14
17
16
18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-
+
+
mA
GND
VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
Boiler 4-20mA
Modulation Output
4-20mA
Burner
Motor
-+


• The Mini-MOD-CNC can operate up to four 0-5V, 0-10V, 1-5V, or 2-10V modulating motors.
• The Mini-Extension can operate up to six 0-5V, 0-10V, 1-5V, or 2-10V modulating motors.
• Wire the (GND) from the modulating motor to the boiler terminal on the Mini-MOD-CNC marked (GND). That
is for boiler D, the modulating (GND) terminal will be 22.
• Wire the (V+) from the modulating motor to the boiler terminal on the Mini-MOD-CNC marked (VLT+). That is
for boiler D, the modulating (V+) terminal will be 23.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18
22
20
19
21 24
23
29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND
VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Mini-MOD-CNC
Boiler Voltage
Modulation Output
Voltage
Burner
Motor
GND V+
HT# 059102-00 B

14 Heat-Timer Corp.

To set the Mini-Extension to a specic letter, remove the wiring cover and switch the Ext A/Ext B
to the desired letter. DO NOT set both extensions to the same letter to avoid errors.

• The Mini-MOD-CNC is equipped with a 6-pin phone socket (RS485) to connect to extension panels and . The Mini-Extension is
equipped with two 6-pin phone sockets to connect to Mini-MOD-CNC and an additional Mini-Extension.
• Set each Extension to a different letter (EXT-A or EXT-B). The Mini-MOD-CNC will assign the stage letters based on the
extension letter selected.
• Extension A will operate stages E - J and all the LEDs will be Green. However, Extension B will operate stages K - P and all the
LEDs will be Red. See "Mini-Extension Layout" on page 5.
• Congure the Modulating and Sequencing Output Types after connecting the Extension panels to be able to congure their outputs.
See "Modulating Output Type" on page 18
• Only use the cable provided for proper operation.
Extension Module
Full Modulation Sequencing Extension
F
H
J
Power
CAUTION: Risk of Electric Shock.
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PWR
L N
1 2
E
3 4
F
5 6
G
7 8
H
9 10
I
11 12
EXTENSION
MODULE
RS-485
Ext A
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
E
G
I
Comm
Ext B
K
M
O
L
N
P
1716
VLTmA
CUR / VLT
201916
VLTmAGND
CUR / VLT
232219
VLTmAGND
CUR / VLT
262522
VLTmAGND
CUR / VLT
J
13 14
K M OL N P
E F G H
K ML N
15
GND
18
GND
21
GND
24
GND
2928
VLTmA
CUR / VLT
323116
VLTmAGND
CUR / VLT
27
GND
30
GND
I J
O P
Mini-MOD Extension A
Extension Module
Full Modulation Sequencing Extension
F
H
J
Power
CAUTION: Risk of Electric Shock.
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PWR
L N
1 2
E
3 4
F
5 6
G
7 8
H
9 10
I
11 12
EXTENSION
MODULE
RS-485
Ext A
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
E
G
I
Comm
Ext B
K
M
O
L
N
P
1716
VLTmA
CUR / VLT
201916
VLTmAGND
CUR / VLT
232219
VLTmAGND
CUR / VLT
262522
VLTmAGND
CUR / VLT
J
13 14
K M OL N P
E F G H
K ML N
15
GND
18
GND
21
GND
24
GND
2928
VLTmA
CUR / VLT
323116
VLTmAGND
CUR / VLT
27
GND
30
GND
I J
O P
Mini-MOD Extension B
SYSTEM
A
B
C
D
12
RUNPROGRAM DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
PROVE
/DHW
SHUTDOWN
/SETBACK
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
Use Copper Conductors Only.
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
/TSTAT
Cable provided with Extension or 4-20mA EMS Interface
Mini-MOD-CNC
Mini-MOD-CNC
Connecting Mini-MOD-CNC
to Two Extension Panels
and 4-20mA EMS Interface
Condensing / Non-Condensing Control
4-20 mA EMS
4-20mA INPUT
+Signal GND
123
RS485
EXTENSION
CONNECTORS
4-20mA EMS Interface
(-)
EMS/BMS Sources
Excitation Voltage
(+)
EMS/BMS
Temperature
Set PointInput
Cable provided with Extension or 4-20mA EMS Interface
OD=25oF SYS= 145oF
<<A>> B <C> D
100% 52% --- ---

• The Mini-MOD-CNC is equipped with a 6-pin phone socket (RS485) to connect to extension panels and 4-20mA EMS Interface.
The 4-20mA EMS Interface is equipped with two 6-pin phone sockets to connect to Mini-MOD-CNC and an additional
Mini-Extension.
• Set Sensor Type to either of the two EMS options. See "Sensor Type" on page 16.
• The interface must be ordered separately.
• Only use the cable provided for proper operation.
HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 15


To be able to change the Mini-MOD-CNC
settings the Program/Run Switch must
be set to Program. The switch is located
under the Enclosure Wiring Cover for
security. The Enclosure Wiring Cover
can be securely closed using a lock.
-------- SETTINGS ----
Season Winter
System Target 140oF
<System Settings>
<Maintenance>
<Histories>
<System Startup>
BACK ▲ ▼ SELECT
-- ARE YOU SURE? --
No
Yes
BACK ▲ ▼ SAVE
--- SENSOR TYPE ---
Reset oF
Reset oC
EMS oF
EMS oC
BACK ▲ ▼ SAVE
--- SWITCH DIFF ---
5 oF
[ ]
BACK ▲ ▼ SAVE
CONDENSING
-- OUTPUT A TYPE --
4-20ma
0-10v
0-5v
2-10v
1-5v
Not Installed
BACK ▲ ▼ SAVE
CONDENSING
-- OUTPUT B TYPE --
4-20ma
0-10v
0-5v
2-10v
1-5v
Not Installed
BACK ▲ ▼ SAVE
CONDENSING
- MODULATING MODE -
Normal
Parallel
BACK ▲ ▼ SAVE
NON-CONDENSING
-- BOILER NUMBER --
2
[ ]
BACK ▲ ▼ SAVE
NON-CONDENSING
- STAGING MODE -
LO/HI/LO/HI
LO/LO/HI/HI
BACK ▲ ▼ SAVE
PROVE/DHW SHARING
Prove
DHW Priority
DHW No Priority
No Priority (Summer)
BACK ▲ ▼ SAVE
- DHW SETPOINT -
180 oF
[ ]
BACK ▲ ▼ SAVE
--- BOOST MODE ---
30 Minutes
Disable
BACK ▲ ▼ SAVE
--- SENSOR FAULT ---
All Off
All On
BACK ▲ ▼ SAVE





CONDENSING
-- BOILER NUMBER --
2
[ ]
BACK ▲ ▼ SAVE
Page 17
NON-CONDENSING
-- OUTPUT TYPE --
On/Off
2-Stage
3-Stage
4-Stage
BACK ▲ ▼ SAVE
Page 19 Page 17
Page 20
Page 20
Page 16
CONDENSING
---- BOILER TYPE ----
Modulating
Staging
BACK ▲ ▼ SAVE
Page 17
- SWITCH SETPOINT -
150 oF
[ ]
BACK ▲ ▼ SAVE
Page 16
HEAVY LOAD
-SEQUENCE #2 GROUP-
No
Yes
BACK ▲ ▼ SAVE
Page 17
NON-CONDENSING
---- BOILER TYPE ----
Modulating
Staging
BACK ▲ ▼ SAVE
Page 18
Page 19
- SETBCK/SHUTDOWN -
Shutdown/Disable
Tstat/Enable
Setback
BACK ▲ ▼ SAVE
Page 19
Page 18
Page 19
Page 19
Page 17
--- SWITCH DELAY ---
0.5Hour
[ ]
BACK ▲ ▼ SAVE
Page 17
Page 18 Page 18
HT# 059102-00 B

16 Heat-Timer Corp.


To be able to change the Mini-MOD-CNC settings the Program/Run Switch must be set to
Program. The switch is located under the Enclosure Wiring Cover for security. The Enclosure
Wiring Cover can be secured using a lock.
SYSTEM
A
B
C
D
Full Modulation Sequencing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
345678910 11 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
30 31
LN
-+
+
TT
OORS-485
mA
GND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mA
GND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
Mini-MOD

Button: MENU/<System Startup>
• When powered, the Mini-MOD-CNC performs a self diagnostics-test on its components.
• On the rst power up, the System Startup screen will appear after the initialization is
complete. If it doesn’t, the Mini-MOD-CNC has already been congured.
• The System Startup menu sets the main parameters that relate to the heating application.
These settings must be set by the installer.
-------- SETTINGS ----
Season Winter
System Target 140oF
<System Settings>
<Maintenance>
<Histories>
<System Startup>
BACK ▲ ▼ SELECT

Reset°F,Reset°C,EMS°F,EMS°C Default:Reset°F
Button: MENU/<System Startup>/..../Sensor Type
• The same Heat-Timer temperature sensor can display in either °F or °C.
• If any of the Reset options is selected, the control will use outdoor reset to calculate the
Target Temperature.
• If any of the EMS options is selected, the control will require the use EMS 4-20mA Interface
(HT# 926741-00).
• Selecting any of the °F options will display all temperatures in degrees Fahrenheit.
• Selecting any of the °C options will display all temperatures in degrees Celsius.
--- SENSOR TYPE ---
Reset oF
Reset oC
BACK ▲ ▼ SAVE
Above the Switch Set Point
Non-Condensing are the Lead Group
Condensing are the Lag Group
Target Switch
Set Point = 120°F
Below the Switch Set Point
Condensing are the Lead Group
Non-Condensing are the Lag Group
120°F
140°F
100°F
SWITCH MODE = Target Temperature
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 91011 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
3031
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
CONDCOND
NON-
COND
NON-
COND
NON-
COND
NON-
COND
CONDCOND
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 91011 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
3031
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Target
Temp
Above the Switch Set Point
Condensing are the Lead Group
Non-Condensing are the Lag Group
Outdoor Switch
Set Point = 30°F
Below the Switch Set Point
Non-Condensing are the Lead Group
Condensing are the Lag Group
30°F
50°F
10°F
SWITCH MODE = Outdoor Temperature
CONDCOND
NON-
COND
NON-
COND
NON-
COND
NON-
COND
CONDCOND
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 91011 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
3031
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
12
RUNPROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
34567 8 91011 12 13 15
14 17
16 18 22
20
19 21 24
23 29
25 27
26 28 32
3031
LN
-+
+
TT
OORS-485
mAGND VLT
SYS ABCD
PWR
CUR / VLT
A
-+
+
mAGND VLT
-+
+
mA
GND VLT
-+
+
mA
GND VLT
+
mA
TEMP
OUTDOOR
OO
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=25oF SYS= 145oF
<<A>> B
100% 52%
Outdoor
Temp

Adjustablefrom0ºF/-18ºCto200ºF/94ºC Default:150ºF/66ºC
Button: MENU/<System Startup>/..../Sensor Type/Switch Setpoint
• It is the Target Temperature Set Point at which the Mini-MOD-CNC will switch between
Condensing Boiler Group and Non-Condensing Boiler Group.
• The Condensing Boiler Group will be the lead group when the Target Temperature is below
the Switch Set Point. However, the Non-Condensing Group will be the lead group when the
Target Temperature is above the Switch Set Point.
- SWITCH SETPOINT -
150 oF
[ ]
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HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 17

Adjustablefrom5Fº/3Cºto20Fº/11Cº Default:5Fº/3Cº
Button: MENU/<System Startup>/..../Switch Setpoint/Switch Diff
• The Switch Differential controls the group switching. It allows the Target Temperature to
drop a specied number of degrees below the Switch Set Point before changing the lead
group over.
• The Switch Differential should be set to a high setting to reduce the switching frequency
between the Condensing and Non-Condensing Boiler Groups, particularly if no Switch
Delay was set. See next setting.
--- SWITCH DIFF ---
5 oF
[ ]
BACK ▲ ▼ SAVE

Adjustablefrom0.0to12.0Hours Default:0.5hours
Button: MENU/<System Startup>/..../Switch Setpoint/Switch Diff/Switch Delay
• The Switch Delay is an additional layer of assurance used to reduce the intermittent change
of the lead group.
• To switch the lead group when the temperature is dropping, the Target Temperature must
drop below the Switch Set Point less the Switch Differential and remain below the Switch
Set Point for the complete Switch Delay period before the switching of the lead group could
take effect. That is, if the Switch Set Point was set to 135ºF, and the Switch Differential
was set to 5Fº, then the Target Temperature must drop below 130ºF for the complete Switch
Delay for the lead group to change from condensing to non-condensing.
• To switch the lead group when the Target Temperature is rising, the Target Temperature must
rise above the Switch Set Point for the complete Switch Delay before the switching of the
lead group could take effect.
• Note that if the Switch Delay was set to 0.0 hours, the Mini-MOD-CNC will utilize it built-
in delays. These delays vary between 3 to 15 minutes based on the Boiler Types used.
--- SWITCH DELAY ---
0.5Hour
[ ]
BACK ▲ ▼ SAVE

Yes,No Default:Yes
Button: MENU/<System Startup>/..../Switch Delay/Heavy Load Seq#2 Group
• This option makes the second group of boilers act as a backup in heavy load conditions.
Thus, allowing them to start after all lead group boilers have run at their maximum capacity.
• If the system was designed to operate both groups of boilers in heavy load conditions, then
select Yes.
• Selecting No will only allow the lead group to operate. The secondary group will remain off
even if the system cannot reach the desired set point.
HEAVY LOAD
-SEQUENCE #2 GROUP-
No
Yes
BACK ▲ ▼ SAVE

Modulating,Staging Default:Modulating
Button: MENU/<System Startup>/..../Heavy Load Seq#2 Group/Condensing Boiler Type
• Select the appropriate boiler type from the list. Each of the types will be followed by a
related additional conguration settings to adjust.
CONDENSING
---- BOILER TYPE ----
Modulating
Staging
BACK ▲ ▼ SAVE

Adjustablefrom1to15 Default:1
Button: MENU/<System Startup>/..../Condensing Boiler Type/ Condensing Boiler Number
• Select the number of condensing boilers. These boilers will occupy the rst letters of the
wiring stages on the Mini-MOD-CNC starting with Stage-A.
• Then, select the number of non-condensing boilers later in the Startup menu. See "Startup
Menu Sequence" on page 15.
CONDENSING
-- BOILER NUMBER --
2
[ ]
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HT# 059102-00 B

18 Heat-Timer Corp.


4-20mA,0-5V,0-10V,1-5V,or2-10VOutputs Default:4-20mA
• If either of the Condensing or Non-Condensing Boiler Groups was set to Modulating as
the Boiler Type, the Mini-MOD-CNC will offer the capability of controlling a variety of
modulating signals. Each boiler can be congured to have a different modulating signal.
• The modulating output for each boiler can be congured to 4-20mA operation (Current)
or any of the voltage ranges (0-5V, 0-10V, 1-5V, 2-10V). Check the modulating boiler to
determine its control requirements.
• When using the Mini-Extension, connect it to the Mini-MOD-CNC prior to conguring the
Output Type. Otherwise, the Mini-MOD-CNC might not recognize them properly.

Normal,Parallel Default:Normal
• Some modulating boilers perform better at higher modulation. For these units, it is
advantageous to run one unit at high modulation than several units at lower modulation. If
the units used are of this type, select Normal. This is the recommended setting for typical
steel and cast iron boilers or boilers with low turndown ratios.
CONDENSING
-- OUTPUT A TYPE --
4-20ma
0-10v
0-5v
2-10v
1-5v
Not Installed
BACK ▲ ▼ SAVE

Make sure that boiler
modulation wiring matches the
signal selected. Warranty will
not cover failed components
caused by improper wiring.
See "Wiring to Modulating
Output" on page 13.
CONDENSING
- MODULATING MODE -
Normal
Parallel
BACK ▲ ▼ SAVE
• There are many condensing boilers that run more efciently at lower modulation. If it
is more energy efcient to run several units at lower modulation than one at high, select
Parallel. This is typically used on water-tube boilers, low mass boilers, or boilers with high
turndown ratios.
• For best Parallel performance, set the Modulation Start % to be equivalent to the lowest
ring rate of the boiler multiplied by 2. That is, if the lowest ring of the boiler was 20%,
set your Modulation Start% to 40%. See "Modulation Start %" on page 32.
• If Parallel is selected, it is preferred to set the Lag Delay to 0. See "Lag Delay" on page 26.
HT# 059102-00 B

Mini-MOD-CNC & Mini-Extension Installation Manual 19


On/Off,2-Stage,3-Stage,4-StageOutputs Default:On/Off
• The Mini-MOD-CNC can sequence any type of multi-stage boiler starting with a single On/
Off and up to a 4-stages. Just select the number of stages per boiler from this menu option.
• The number selected applies to all sequencing boilers within that group whether it is
condensing or non-condensing.
NON-CONDENSING
-- OUTPUT TYPE --
On/Off
2-Stage
3-Stage
4-Stage
BACK ▲ ▼ SAVE

Lo/Hi/Lo/Hi,Lo/Lo/Hi/Hi Default:Lo/Hi/Lo/Hi
• During low load conditions, some boilers run more efcient when the lower stages are
energized alone than with the higher stages. For these types of boilers select Lo/Lo/Hi/Hi.
Then, the Mini-MOD-CNC will sequence the lower stages of all boilers their Mode is set to
Auto before sequencing the higher stages.
• For the rest of the boiler types, the Lo/Hi/Lo/Hi should allow the staging of the lower stage
of the lead boiler followed by the higher stage of the same boiler. Then when more stages
are needed, it will re the lower stage of the lag boiler followed by the higher stage of the
lag boiler.
NON-CONDENSING
- STAGING MODE -
LO/HI/LO/HI
LO/LO/HI/HI
BACK ▲ ▼ SAVE

Prove,DHWPriority,DHWNoPriority,NoPriority(Summer) Default:Prove
Button: MENU/<System Startup>/..../Prove-DHW Sharing
• This setting determines the functionality of Input Terminals 29 and 30.
• When Prove is selected, the Mini-MOD-CNC will not start any boiler unless Prove terminals
are shorted/closed. However, it will allow the System relay to function normally.
PROVE/DHW SHARING
Prove
DHW Priority
DHW No Priority
No Priority (Summer)
BACK ▲ ▼ SAVE
• Using the terminals to connect to an aquastat for a Domestic Hot Water call and selecting any of the DHW options will raise the
calculated water temperature to the DHW Set Point (See next setting).
• The Domestic Hot Water Priority option de-energizes the System relay during domestic hot water calls for a period of one hour.
If after the priority period the DHW call did not expire, the System relay will energize providing heat to the building and the
temperature target will remain at the DHW Set Point. After the DHW call ends, the set point will drop to satisfy the reset ratio or
set point.
• Domestic Hot Water No Priority option allows the System relay to remain energized during a domestic hot water call (aquastat call
on terminals 29 and 30). However, in Summer, Shutdown, No Tstat call for heat, or when outdoor temperature is above Outdoor
Cutoff, a DHW call will energize the System relay. After the DHW call terminates, the System relay will continue to run for the
System Run-On period before turning off.
• Domestic Hot Water No Priority (Summer) behaves the same as the DHW No Priority. The only difference is that in Summer,
Shutdown, No Tstat call for heat, or when outdoor temperature is above Outdoor Cutoff, a DHW call WILL NOT energize the
System relay except for the Run-On delay after the DHW call ends.


Adjustablefrom140ºF/60ºCto200ºF/93ºC Default:180ºF/82ºC
Button: MENU/<System Startup>/..../DHW Set Point
• On a DHW call, the Mini-MOD-CNC will raise the target to the DHW Set Point until the
DHW call expires.
- DHW SETPOINT -
180 oF
[ ]
BACK ▲ ▼ SAVE

ShutdownInput,TstateInput,SetbackInput Default:ShutdownInput
Button: MENU/<System Startup>/..../Setback\Shutdown
• The Mini-MOD-CNC has two levels of heat, a Normal/Day and a Setback/Night. The
Normal/Day is good for when buildings are occupied and people are active. The Setback/
Night holds a lower system temperature for night periods or when buildings are unoccupied.
- SETBCK/SHUTDOWN -
Shutdown/Disable
Tstat/Enable
Setback
BACK ▲ ▼ SAVE
HT# 059102-00 B

20 Heat-Timer Corp.
• When Shutdown or Tstat is selected, the Day/Night Schedules will be available in the operating menu. See "Shutdown/Tstat/
Setback Mode" on page 19. Terminals 31 and 32 will function as a Shutdown (Turn off boilers when shorted) or as a Tstat (Turn off
boilers when opened). However, a call for DHW will bring the boilers on.
• When Setback is selected, the External Signal option will switch the Mini-MOD-CNC to Setback mode when terminals 31 and 32
are shorted. This allows an external device or control to provide the setback signal. No scheduling or boost menu options will be
available with Setback.


30Minutes,Disabled Default:30Minutes
Button: MENU/<System Startup>/..../Boost Mode
• The morning Boost is designed to return the building to comfortable ambient temperatures
after the cooler Night (Setback) period. The Mini-MOD-CNC will accomplish this
by running elevated water temperatures (will add Setback setting to calculated water
temperature) for 30 minutes before the start of the Day schedule setting. That is, if the
normal day set point at a specic outdoor was 145˚F and the Setback setting was 20˚F, the
boost will raise the system calculated temperature to 165˚F for 30 minutes before the start of
the Day Schedule setting.
• If no Boost is needed, then simply select Disabled from the Boost Menu.
• Boost is only available if Shutdown or Tstat is selected as an option. See "Shutdown/Tstat/
Setback Mode" on page 19.
--- BOOST MODE ---
30 Minutes
Disable
BACK ▲ ▼ SAVE

AllOff,AllOn Default:AllOn
Button: MENU/<System Startup>/..../Sensor Fault
• The Sensor Fault will determine the operating status of all output stages that has their Mode
set to Auto when a sensor reads Short or Open.
• When All-On is selected, the Mini-MOD-CNC will turn all boilers On to 100% when
the System reads Short or Open and the outdoor temperature is below Outdoor Cutoff.
However, when the Outdoor reads Short or Open, the Mini-MOD-CNC will try to maintain
the Maximum Water Temperature.
• When All-Off is selected, the Mini-MOD-CNC will turn all boilers Off when either the
System or the Outdoor sensor reads Short or Open. However, when the Outdoor reads Short
or Open, the Mini-MOD-CNC will try to maintain the Minimum Water Temperature.
--- SENSOR FAULT ---
All Off
All On
BACK ▲ ▼ SAVE

A good practice after performing any Startup menu modication is to
check all operating settings and adjustments to match the new settings.

To Reset the Mini-MOD-CNC control to its original factory defaults, power down the
control. Hold down the two right most buttons while powering the control back up until the
Total Clear Started screen appears. The Display will direct you to the Startup
menu to program the control after the defaults are loaded.
TOTAL CLEAR STARTED
Release buttons
and
Please Wait
NOTE: When resetting the control to original factory defaults all control settings will be overwritten and will no longer exist.

Do not turn off power to control until all Startup settings have been made. Otherwise, the next
power-up will be set to many Startup factory settings that might not t your application.
HT# 059102-00 B