HBX CPU-0500 User manual

HBX Control Systems Inc.
Installation Manual
Central Processing Unit 0500
Version 2.50
CPU-0500
Mixing • Boiler Staging • Differential Setpoint • Geothermal • Pump Sequencer

Control Systems Inc.
Comfort
Control
Innovation
HBX CPU-0500 HVAC Control
Version 2.50
Table of Contents
Table of Contents
Control Systems Inc.
Comfort
Control
Innovation
HBX CPU-0500 HVAC Control
Version 2.50
Table of Contents
TABLE OF CONTENTS
Introduction ............................................................................................ 1-2
Safety Symbols & Warnings ................................................................... 1
Receipt & Inspection .............................................................................. 1
Description .............................................................................................. 2
Technical Data and Dimensions ........................................................... 3
Wiring & Installation ............................................................................... 4
Wiring ....................................................................................................... 4
Jumper .................................................................................................... 4
Dipswitch ................................................................................................. 4
Installation ................................................................................................ 4
Programming CPU-0500 ......................................................................... 5-19
Multicolour Backlit Display ..................................................................... 5
Dial Operation & Set/Status Mode ....................................................... 6
Programming Scroll Mode ..................................................................... 6
Programming Change Mode ................................................................6
Control Mode .......................................................................................... 7
Programming the Control ................................................................. 8
Status Screens ..........................................................................................8
Mixing Control Programming ................................................................ 9-11
Boiler Control Programming .................................................................. 12-14
Differential Setpoint Programming ....................................................... 15
Geothermal Control Programming ...................................................... 16-18
Pump Sequencer .................................................................................... 19
Sample Wiring and Diagrams ............................................................... 20-26
Warranty Information .............................................................................. 28

HBX CPU-0500 HVAC Control
Version 2.50
© HBX Control Systems Inc. 2013 Page 1
Control Systems Inc.
Comfort
Control
Innovation
HBX CPU-0500 HVAC Control
Version 2.50
Table of Contents
HBX CPU-0500 HVAC CONTROLLER
INTRODUCTION
This manual will help with the installation, parameter setting, troubleshooting
and general maintenance requirements for the controller. To guarantee the
safe and reliable operation of this control, you must rst read this manual in
detail and take particular note to any and all warnings or caution directives
prior to connecting to AC power.
Only suitably qualied individuals with formal training in electrical and HVAC
controls should attempt the installation of this equipment. Incorrect wiring
and installation will affect the warranty provided with this unit. Wiring must be
completed in accordance with the codes and practices applicable to the
jurisdiction for the actual installation.
Please consult and install the heating appliance in accordance with
manufacture’s recommendations.
SAFETY SYMBOLS & WARNINGS
Extreme Hazard
This action poses a serious threat that could
result in personal injury or death, as well as
permanent damage to the equipment.
Proceed with caution.
Moderate Hazard
This action may cause personal injury or have
adverse effects on the installation process if
handled incorrectly.
Disconnect Power Source
The presence of low voltage(24VAC) or high
voltage(120VAC) could result in personal injury
or permanent damage to components or
equipment.
Point of Interest
This point claries pertinent information, or
brings your attention to an action that may
have adverse effects on the installation
process.
Drawing Reference
Refer to the specied electrical or mechanical
drawing at the back of the manual.
Only suitably qualied individuals with formal
training in electrical and HVAC controls should
attempt the installation of this equipment.
Incorrect wiring and installation will affect the
warranty provided with this unit. Wiring must be
completed in accordance with the codes and
practices applicable to the jurisdiction for the
actual installation.
The HBX CPU-0500 is a microprocessor based
controller and as such is not to be regarded as a
safety (limit) control. Please consult and install
the heating or cooling appliance in accordance
with the manufacturer’s recommendations.
RECEIPT & INSPECTION
After receiving, inspect the unit for any possible
physical damage that may have occurred during
transportation.
After unpacking the unit make sure the box contains:
• 1 x Remote Outdoor sensor
• 2 x Universal sensors
• 1 x Terminal Screwdriver (2.5mm)
• 2 x Cable ties

HBX CPU-0500 HVAC Control
Version 2.50
Page 2
HBX CPU-0500 HVAC CONTROLLER
DESCRIPTION
The CPU-0500 is designed to be a stand-alone Outdoor Reset Control device. The purpose and function of
the CPU-0500 is to provide control for multiple applications. The applications are selectable through single dial
operation on the programming interface and consist of Boiler, Mixing, Differential Setpoint, Geothermal Control or
Pump Sequencer.
Mixing Control
As a Mixing Control, the CPU-0500 has the capability to run a single On/Off or modulating boiler. Mixing types
include Modulating Mixing, PMIp or Floating Action.
Boiler Control
The use of the CPU-0500 as a Boiler Control allows the capability to run up to two On/Off boilers, or a single
modulating boiler with DHW requirements.
Differential Setpoint Control
The CPU-0500, when selected as a Setpoint Control, will allow for Dual or Differential Setpoint requirements.
Geothermal Control
Manages applications using heat pumps, chillers or compressors. The control handles the reversing valve, up to 2
heat pumps, hot tank and cold tank, or a single hot/cold tank. This mode also allows for a built-in backup feature.
Pump Sequencer
This control allows the system to sequence and cycle pumps, override pumps and turn the pump off when the
outdoor temperature goes above a certain value (WWSD).

HBX CPU-0500 HVAC Control
Version 2.50
© HBX Control Systems Inc. 2013 Page 3
DIMENSIONS
TECHNICAL DATA & DIMENSIONS
TECHNICAL DATA
Specications:
Built in 2 Amp fast acting fuse
3 x Thermistor Input
(10K Ohm)
2 x Miscellaneous Input Signal
2 x Relay Outputs
Dry Contacts
(240VAC 10Amps)
1 x Modulating Output / 2Amp Dry Contact
(4-20mA or 1-10VDC)
Weight:
0.408Kg
Dimensions:
100mm W x 168mm H x 70mm
ETL Listings:
Meets CSA C22.2 No. 24
Meets UL Standard 873
ETL Control No. 3068143
Storage:
50°F to 104°F (10ºC to 40ºC)
CPU ECO
CPU-0500
Input
Signals (2)
Mod or
ON/OFF Boiler
Sensor (2)
Outdoor
Sensor
120
VAC
Pump
Outputs (2)
Outdoor
Sensor
120
VAC
Heating or
Cooling
Demand
Sensor (2)
Heat
Pump 1
Heat
Pump 2
/ Backup
Reversing
Valve
Multicolour
backlit display
Control dial
Barcode
& Serial #
70mm 66mm17
Side View Front View
Rear View Top View
168mm
100mm
63.2mm
86mm
Bottom View

HBX CPU-0500 HVAC Control
Version 2.50
Page 4
1, 2: Demand Signal 1
Apply heat demand from a dry contact.
2, 3: Demand Signal 2
Used for DHW or Setpoint demand. Dry contacts only.
4, 5: Modulating / Boiler Contacts / Heat Pump 1
Modulating, Boiler 1, and Heat Pump 1 Output. Also
used in differential setpoint output for modulating
devices.
Sensor Inputs
6, 9: Primarily used for boiler temperature but also
used for setpoint 1 temperature in Setpoint controls or
hot tank temps.
7, 9: Used for DHW or setpoint on Boiler controls and
low temperature system temperature on Mixing
control. Also used for setpoint 2 temperature or cold
tank temps.
8, 9: Outdoor temperature. Only on Boiler, Mixing and
ECO controls.
15, 16: Relay 2
Generally used as a pump contact unless in Setpoint
mode or reversing valves (ECO Mode).
13, 14: Relay 1
This relay is generally a pump contact or can be used
as a second stage boiler or second heat pump.
(Relays 1 & 2 are dry contacts and rated for a
maximum of 10 Amps.)
Please ensure no power is applied to pin 4,5
when in any modulating mode.
10 A
RL
1
RL
1413
1
10 A
RL
2
RL
1615
2
Central Processing Unit
CPU-0500
HBX
DS
1
2
DS
1
31
2
DO NOT
CONNECT
POWER
HERE
GR
120
12
N
L
1110
11
TM
32
7
TM TM
6 8 9
BL
1
BL
54
1
2A
4-20mA
1-10v
+ - DO NOT
CONNECT
POWER
HERE
yellow blueblack
Extra Relay 2
Extra Relay 1 / boiler 2
Supply Power 120 VAC
Demand Inputs
Boiler Contacts
Sensor Inputs
WIRING AND INSTALLATION
Wiring
All signal wiring must be with a minimum of 18AWG wire at a
maximum of 500ft.
Jumper
This jumper is used to add or remove arc suppression from the
relay 2 contacts.
If you are using the CPU-0500 in Mixing Mode and doing PMIp
injection the jumper should be left in place. Remove the jumper
for all other modes.
Dipswitch
The CPU-0500 is able to output either a 4-20mA signal or a
1-10VDC signal from the 4 & 5 contacts when in Modulating
Mode.
For 4-20mA the dipswitch is set to OFF (up position).
For 1-10VDC the dipswitch is set to ON (down position).
onon
on
on
CPU-0500 Rear View
DipswitchJumper
Installation
The CPU-0500 is designed to be wall mounted, DIN rail mounted or installed in a separate electrical enclosure.
The unit should be mounted inside and protected from falling water and high humidity conditions. With all the
covers in place it is designed to protect any individual from accidental electrical shock.

HBX CPU-0500 HVAC Control
Version 2.50
© HBX Control Systems Inc. 2013 Page 5
PROGRAMING
MULTICOLOUR BACKLIT DISPLAY
The Multicolour Backlit Display is one of the key features of the HBX Controls stand-alone CPU-0500 Control.
Depending on which mode of operation is selected the screen colour will change to indicate information
about the status of the system.
Screen Colours
Mixing and Staging:
Light Blue - NO Heat Demand
Red - Demand (DHW or Heat Demand) and Boiler running
Green/Yellow - Heat Demand ON, boiler running but in boiler protection
Dark Blue - Heat Demand ON and boiler satised
Geothermal:
Green/Yellow - Demand on, no heat pumps running.
Red - Demand and heat pumps running (Heating mode).
Dark Blue - Demand and heat pumps running (Cooling mode)
Light Blue - No demands
Pump Sequencer:
Light Blue - No Demand
Dark Blue - Pump Running
Red - No Flow Alarm
DHW
Gpm
Heat Cool
1 2
°F
110.0
Status
Set
Indicates changing
settings in set mode.
Relay 1 is ON.
Relay 2 is ON.
DHW priority.
Indicates WWSD.
Indicates CWSD.
Indicates modulation
percentage. Shows for
modulating boilers and MOd
output in Mixing mode.
Indicates flow
Indicates Setpoint
Shows current temperature.
Indicates DHW demand.
Indicates heat demand.
Indicates cool demand.
Indicates stages.
Indicates current
viewing mode.
1 2

HBX CPU-0500 HVAC Control
Version 2.50
Page 6
DIAL OPERATION & SET/STATUS MODE
There are 2 modes for the control, programming and status screens. The programming screen is identied by
the SET icon on the top/middle left corner. The status screen is indicated by the STATUS icon the top/middle left
corner.
By pressing the dial in for more than one second will allow the user to
access the programming section of the control.
PROGRAMMING SCROLL MODE
To enter this mode the dial must be pressed in for more than one
second. When the SET indicator comes on release the button, you will
now be in Programming Scroll Mode.
In this mode turning the dial to the left or right will scroll through the
programming options on the control. Each setting will be indicated by
the icons around the screen as well as the temperature/number of that
setting.
If you allow the control to idle in Programming Scroll Mode for thirty
seconds the control will automatically return to STATUS mode.
PROGRAMMING CHANGE MODE
To change a setting you must press the dial in momentarily and an
arrow will appear in the top left corner of the screen. This will indicate
the control is in the Programming Change Mode. While in the change
mode the user will be able to change the setting of that selection by
turning the dial to the left or right. Once you have nished changing the
setting, press the dial momentarily and the arrow in the top left corner
will disappear. This will indicate that the user is no longer in Programming
Change Mode.
CPU05CPU-0500
I
n
p
ut: 120V
A
C 60Hz 10
A
Output: 4-20mA/1-10V
110V
CPU05CPU-0500
I
n
p
ut: 120VAC 60Hz 10
A
Output: 4-20mA/1-10V
110V
Set
CPU05
CPU-0500
I
n
p
ut: 120VAC 60Hz 10
A
Output: 4-20mA/1-10V
110V
Status
CPU-0500Input: 120VAC 60Hz 10A Output: 4-20mA/1-10V
CPU-0500
Set

HBX CPU-0500 HVAC Control
Version 2.50
© HBX Control Systems Inc. 2013 Page 7
Boiler Mode
Programming for this mode can be found on pages 12 through 14. This mode is used
when running boilers only. The boiler congurations available in this mode are single
modulating, On/Off boiler, and two stage On/Off boiler. With single boiler operation the
control will run the boiler pump and DHW pump. In two stage operation the control will
not run the DHW pump.
Status
Set
Differential Setpoint Mode
Programming for this mode can be found on page 15. This mode is used when running
a differential setpoint. This may be used with solar installations. This mode also includes
a high temperature dump feature from the tank so that multiple tanks can be used. In
differential mode, the control will also send a modulating signal output based on how
far the control is from the differential. This can be used to run a pump in modulating
applications for constant ow.
Status
Set
Geothermal Mode
Programming for this mode can be found on pages 16 through 18. This mode is used
when running heat pumps/chillers or geothermal related installations. The control will run
up to 2 stages of heat pumps, a reversing valve for heating and cooling applications, as
well as hot and cold tanks. This mode also allows for a built-in backup feature.
Status
Set
Pump Sequencer
Programming for this mode can be found on page 19. This mode is used to provide
pump control for two pumps and maintain the feed water ow through the boiler. This
control allows the system to sequence and cycle pumps, override pumps and turn the
pump off when the outdoor temperature goes above a certain value (WWSD)
Status
Set pmp
Mixing Mode (Default = Mixing Mode)
Programming for this mode can be found on pages 9 through 11. This mode is used
when running mixing pumps or valves. Mixing congurations include PMIp, Modulating,
and Floating Valve. When in Pulse Modulated Injection (PMIp) or Floating Valve the
control will run single modulating or On/Off boiler. In modes other than Floating Valve
the control will run the injection and system pump.
Status
Set
CONTROL MODE
The programming instructions for the CPU-0500 are broken down into the ve control modes listed below. When
the control is rst plugged in you are asked to select which control mode you would like your CPU-0500 to
operate in. To select your control mode simply turn the dial to the left or right to select the correct mode then
wait ve seconds to accept your selection.

Page 8
REPROGRAMMING THE CONTROL
To reprogram the control for a different mode simply unplug the control and wait ten seconds before plugging
the control back in. This will allow you to manually select a different mode for the control. The control will not
reset to factory defaults.
Boiler Temperature
DHW Target
(boiler mode only) Low Temperature System
Target (mixing mode only)
Boiler TargetDHW Temperature
(boiler mode only)
Low Temperature System
Temperature
(mixing mode only)
°F
Boiler Temp
82.0
Status
DHW
°F
Temp
105.0
Status
°F
System
Temp
108.0
Status
°F
Setpoint
Boiler Temp
150.0
Status
°F
Setpoint
DHW
Temp
130.0
Status
°F
Setpoint
System
Temp
70.0
Status
STATUS SCREENS (BOILER & MIXING)
Outdoor Temperature
°F
Out Temp
30.0
Status
Setpoint 1 Temperature
1
°F
Setpoint
Temp
82.0
Status
Outdoor
Temperature
°F
Out Temp
Status 10.0
Outdoor
Temperature
°F
Out Temp
Status 70.0
Hot Tank
Temperature
°F
System
Temp
Status
100.0
1
Pump 1 Alarm
Status ALM1
STATUS SCREENS (DIFFERENTIAL SETPOINT)
STATUS SCREENS (GEOTHERMAL)
STATUS SCREENS (PUMP SEQUENCER)
Setpoint 2 Temperature
2
°F
Setpoint
Temp
105.0
Status
Hot Tank Setpoint
°F
Setpoint
System
Temp
Status
115.0
1
Pump 2 Alarm
Status ALM2
Cold Tank Setpoint
°F
Setpoint
System
Temp
Status 50.0
2
Cold Tank
Temperature
°F
System
Temp
Status
2
Status screens will differ depending upon the operation mode you have selected.

Page 9
Design Room Temperature
This is the design room temperature. It is used in the outdoor reset design calculation. Set it
to the approximate desired room temperature.
(50°F to 120°F) Default: 70°F
Room
Temp
70.0
Set
Design Outdoor Temperature
This is the design outdoor temperature. It is used in the outdoor reset design calculation. Set
the maximum temperature you would like the control to be at.
(-50°F to 150°F) Default: -10°F
Out Temp
10.0
Set
Minimum Boiler Temperature
This is the minimum boiler temperature. This setting will vary depending on the type of boiler
you are running. This is boiler supply temperature so keep that in mind when selecting this
feature. If the minimum boiler temperature is set to OFF then the boiler demand will always
be ON when a heat demand is present.
(OFF / 51 °F to 200 °F)
Default: OFF
Min
Boiler Temp
off.
Set
Minimum Low Temperature System Temperature
This is the minimum system temperature. Set this temperature to the minimum temperature
you would like to see in the low temperature system loop.
(40°F to 190°F) Default: 70°F
Min
System
Temp
70.0
Set
► MIXING CONTROL PROGRAMMING
Design Boiler Temperature
This is the design boiler temperature. It is used in the outdoor reset design calculation and is
also the maximum setting for the boiler.
(50°F to 200°F) Default: 190°F
Boiler Temp
190.0
Set
Design Low Temperature System Temperature
This is the design low temperature system temperature. It is used in the outdoor reset design
calculation for the low temperature reset curve.
(50°F to 190°F) Default: 135°F
System
Temp
135.0
Set

Page 10
DHW Boiler Setpoint
This setting is used to set the desired boiler setpoint when there is a DHW demand. This can
be triggered from an aquastat.
(50°F to 200°F) Default: 180°F
When mixing, this can only be triggered by an aquastat.
Boiler
DHW
Temp
180.0
Set
Screens applicable in Modulating Mixing Mode only:
Boiler Selection
This setting is used to select what boiler(s) are connected to the control.
Selection Types:
MOD: Modulating Boiler
1: Single Stage ON/OFF Boiler
Default: 1.
Boiler
Stage
Set
Screen Applicable in Single Stage On/Off Boiler Mode only:
Boiler Differential
This is the differential for the boiler. Adjust this setting to the desired differential for the boiler.
(2°F to 60°F) Default: 20°F
Eg.) 6°F differential would be 3°F above and 3°F below.
Refer to Diagram #7 Single On/Off Boiler with Injection
Diff
Boiler
20.0
Set
Warm Weather Shut Down (WWSD)
This setting is used to set the temperature at which the CPU-0500 will go into WWSD. Above
this temperature the system will be shut off.
(20°F to 150°F) Default: 75°F
Max
Out Temp
75.0
Set
Modulating Step Time
When in Mixing mode this is the setting for the steps between modulating up or down on the
device.
(1s to 300s) Default: 10s
Refer to Diagram #8 Modulating Mixing.
Stage
Time
10.0
Set
Minimum Modulation Percentage
This setting is used to set the minimum modulation level that the device can go down to. It
can also be used to set the minimum positions on valves.
(10% to 60%) Default: 20%
Stage
%
20.0
Set

Page 11
Mixing Type
This setting is used to select your Mixing type.
In: PMIp Injection Pump
MO: Modulating Output (4-20mA or 1-10vDC)
FL: Floating action valve (power open / power close)
Default: In
Set
DHW Priority
This setting is used to set the DHW priority. If set to ON then the System Pump will shut off
when there is a DHW call. The priority time is 60 minutes. In Mixing mode the injection device
will shut off in a priority situation.
(ON/OFF Default: OFF
On
Time
DHW
off.
Set
Celsius & Fahrenheit
Use this setting to change the display format from °C to °F.
(°C/°F) Default: °F
°F
.
Set
Heat Demand
1) ON: This setting indicates that the CPU-0500 is in a permanent heat demand. Use instead
of attaching a thermostat.
2) OFF
(ON/OFF) Default: OFF
Heat
off.
Set

Page 12
Screen Not Applicable in MOD Boiler Mode:
Design Room Temperature
This is the design room temperature. It is used in the outdoor reset design calculation. Set it
to the approximate desired room temperature.
(50°F to 120°F) Default: 70°F
Room
Temp
70.0
Set
Minimum Boiler Temperature
This is the minimum boiler temperature. This setting will vary depending on the type of boiler
you are running. This is boiler supply temperature so keep that in mind when selecting this
feature.
If the minimum boiler temperature is set to OFF then the boiler demand will always be ON
when a heat demand is present.
(OFF / 51°F to 200°F) Default: OFF
This is used when you would like the modulating boiler to control itself.
Design Outdoor Temperature
This is the design outdoor temperature. It is used in the outdoor reset design calculation. Set
the maximum temperature you would like the control to be at.
(-50°F to 150°F) Default: -10°F
Out Temp
10.0
Set
Min
Boiler Temp
off.
Set
Boiler Differential
This is the differential for the boiler. Adjust this setting to the desired differential for the boiler.
(2°F to 60°F) Default: 20°F
Eg.) 6°F differential would be 3°F above and 3°F below.
Diff
Boiler
20.0
Set
Warm Weather Shut Down (WWSD)
This setting is used to set the temperature at which the CPU-0500 will go into WWSD. Above
this temperature the system will be shut off.
(20°F to 150°F) Default: 75°F
Max
Out Temp
75.0
Set
Design Boiler Temperature
This is the design boiler temperature. It is used in the outdoor reset design calculation and is
also the maximum setting for the boiler.
(50°F to 200°F) Default: 190°F
Boiler Temp
190.0
Set
► BOILER CONTROL PROGRAMMING

Page 13
Screens applicable in Modulating Mode only:
Screen Applicable in Boiler Two Stage Mode only:
Screen Not Applicable in Boiler Two Stage Mode:
DHW Target
This setting is used to set the desired DHW tank temperature.
(OFF/1°F to 200°F) Default: 130 °F
Refer to Diagram #3 Single Modulating Boiler with DHW or #4 Single On/Off Boiler
with DHW.
Setpoint
DHW
130.0
Set
Modulating Step Time & Staging Lag Time
When the boiler is set to MOD mode this setting sets the time between the steps when the
boiler needs to increase or decrease the ring rate.
(1s to 300s) Default: 10s
Boiler Two Stage
When the boiler is set for two stages this setting will be set for the minimum lag time between
boiler stages.
(1m to 300m) Default: 10m
Refer to Diagram #5 Two Stage Boiler.
DHW Boiler Setpoint
This setting is used to set the desired boiler setpoint when there is a DHW demand. This can
be triggered from either a thermistor or an aquastat.
(50°F to 200°F) Default: 180°F
When stage 2 is selected this can only be triggered by an aquastat.
DHW Differential
This is the differential for the DHW tank. Set this setting to the desired differential for the DHW
tank.
(2°F to 60°F) Default: 6°F
Eg.) 6°F differential would be 3°F above and 3°F below.
Diff
DHW
6.0
Set
Boiler
DHW
Temp
180.0
Set
Stage
Time
10.0
Set
Stage
Time
10.0
Set
Minimum Modulation Percentage
This setting is used to set the lowest modulation level the boiler can go down to.
(10% to 60%) Default: 20%
Stage
%
20.0
Set

Page 14
Boiler Selection
This setting is used to select what boiler(s) are connected to the control.
Selection Types:
1: Single Stage ON/OFF Boiler
2RT: 2 Stages of ON/OFF Boiler with Rotation
2: 2 Stage Boiler with No Rotation
MOD: Modulating Boiler
Default:1
The time of rotation between heat pumps is 48 hours of run time. It means that the
boilers are going to rotate when the rst boiler exceeds the second by 48 hours and
vice versa.
Boiler
Stage
Set
Heat Demand
1) ON: This setting indicates that the CPU-0500 is in a permanent heat demand. Use instead
of attaching a thermostat.
2) OFF
(ON/OFF) Default: OFF
Heat
off.
Set
Celsius & Fahrenheit
Use this setting to change the display format from °C to °F.
(°C/°F) Default: °F
°F
.
Set
DHW Priority
This setting is used to set the DHW priority. If set to ON then the System Pump will shut off
when there is a DHW call. The priority time is 60 minutes. In Mixing mode the injection device
will shut off in a priority situation.
(ON/OFF) Default: OFF
Boiler Pump Selection
1) ON: This setting is used to setup the boiler pump contact. If this setting is on, then the
boiler pump contact will come on only if the boiler is being enabled. This setting also works
for modulating boilers.
2) OFF: If this setting is off the boiler pump contact will come on with the demand.
Default: OFF
The setting can be used as a boiler enable signal for modulating boilers.
On
Time
DHW
off.
Set
Boiler Pump
off.
Set

Page 15
Setpoint 1 Differential
This setting is used to set the differential between setpoint 2 temperature and setpoint 1
temperature.
When the difference exceeds this then relay #1 will engage.
(2°F to 100°F) Default: 10°F
Diff
1
Setpoint
10.0
Set
Setpoint 1 Lagtime
This setting is used to set a lagtime on setpoint 1. When this is set above zero the control will
wait the predetermined time before turning the relay for the setpoint back on.
(0s to 240s) Default: 0s
This will help to stop short cycling of the connected device.
TimeOff
1
Setpoint
0.0
Set
► DIFFERENTIAL SETPOINT PROGRAMMING
Celsius & Fahrenheit
Use this setting to change the display format from °C to °F.
(°C/°F) Default: °F
°F
.
Set
Setpoint 1 Heating/Cooling
This setting is used to set whether or not you would like setpoint 1 to be a heating or cooling
setpoint. Set this to OFF for a cooling setpoint.
(OFF/ON) Default: ON
Close
Open
1
Setpoint
oN.
Set
Mixing Modulating Mode
When using modulating output this is the setting for the steps between modulating up or
down of the device.
(1s to 300s) Default: 6s
Refer to Diagram #10 Differential Setpoint.
Stage
Time
6.0
Set
Minimum Modulation Percentage
This setting is used to set the minimum modulation level that the device can go down to. It
can also be used to set the minimum positions on valves.
(10% to 60%) Default: 30%
Stage
%
30.0
Set
High Temperature Dump
This setting is used as a high temperature dump when the setpoint 1 temperature exceeds
this temperature. When this happens relay #2 will engage.
(5°F to 200°F) Default: 180°F
1Max
°F
Setpoint
180.0
Set
Screens applicable for Modulating Output only:

Page 16
► GEOTHERMAL CONTROL PROGRAMMING
System Temperature 1
Set the System Temperature 1 for the desired heating temperature. When a heat demand is
present and not in WWSD, the control will target this temperature for heating.
(50°F to 200°F) Default = 110°F
°F
System
Temp
Set110.0
1
System Temperature 2
Set the System Temperature 2 for the desired cooling temperature. When a cooling demand
is present and not in CWSD, the control will target this temperature for cooling.
(20°F to 100°F) Default = 50°F
If there is no thermistor attached to pins 7 and 9, the control assumes single tank
operation.
°F
System
Temp
Set 50.0
2
Design Room Temperature
This is the design room temperature. It is used in the outdoor reset design calculation. Set it
to the approximate desired room temperature.
(50°F to 120°F) Default: 70°F
Room
°F
Temp
Set 70.0
Design Outdoor Temperature
This is the design outdoor temperature. It is used in the outdoor reset design calculation. Set
this temperature to the value at which you would like to hit your maximum temperature in
from the control.
(Off/ -50°F to 126°F) Default: OFF
Outdoor reset is not applicable if the control is set to OFF.
Out Temp
Set OFF.
Heating Differential
This setting is used to set the heating differential. This option sets the tank differential when
heating.
(2°F to 50°F) Default: 10°F
Eg.) 6°F differential would be 3°F above and 3°F below.
°F
System
Set 10.0
1
Diff
Cooling Differential
This setting is used to set the cooling differential. This option sets the tank differential when
cooling.
(2°F to 50°F) Default: 10°F
Eg.) 6°F differential would be 3°F above and 3°F below.
°F
System
Set 10.0
2
Diff
Cold Weather Shut Down
This setting is used to set the temperature at which the CPU-0500 will go into CWSD. Below
this temperature the system will not allow the control to instigate cooling mode.
(-50°F to 150°F) Default: 75°F
Min
°F
Out Temp
Set 75.0

Page 17
Warm Weather Shut Down (WWSD)
This setting is used to set the temperature at which the CPU-0500 will go into WWSD. Above
this temperature the system will not allow the control to instigate heating mode.
(20°F to 150°F) Default: 70°F
Max
°F
Out Temp
Set 70.0
Use Backup Temperature
Set this temperature to the desired outdoor temperature that will allow the backup (stage 2)
to come on. When the temperature resides above this value, the backup will not initiate a
heat demand.
(Off/-50°F to 199°F) Default: OFF
If set to OFF, the backup (stage 2) will come on only based on time delay.
Heat
Boiler
Set OFF.
On
Heating or Cooling Priority
Designates either heating or cooling priority in a system.
OFF = Cooling priority
ON = Heating priority
(ON/OFF) Default: OFF
Heat
System
Set OFF.
On
Off
Minimum Lag Time
Choose the minimum lag time between heat pumps in a multi-heat pump application.
(1 minute to 30 minutes) Default: 3 minutes
Set 3.0
Time
Stage
Celsius or Fahrenheit
Use this setting to change the display format between °F and °C.
(°F/°C) Default: °F
°F
Set .
Stage Selection
1: Single stage heat pump.
2 RT: 2 stages of heat pumps with rotation.
2: 2 stages of heat pumps without rotation.
Default: 1
The time of ratation between heat pumps is 48 hours of run time. It means that the
heat pumps are going to rotate when the rst heat pump exceeds the second by 48
hours and vice versa.
Use the setting when a backup is being used. This way the backup will not rotate
into the number 1 position.
System
Set
1 .
Stage

Page 18
Backup Differential
This setting can be used with the USE Backup Temperature or on its own to bring the backup
on. This setting is used to set a differential on the tank at which you would like the backup to
come on. This setting will override the Use Backup Temperature. eg. 20.0°F Diff and System/
Setpoint 100.0°F. The backup will come on at 80.0°F once the stage time has elapsed.
(OFF/20 to 50°F) Default: 20°F
Rotate Cycles
Set the number of cycles at which you would like to rotate the heat pumps.
(OFF/2 to 240) Default: OFF
°F
Boiler
Set20.0
Diff
On
Stage
SetOFF.
Off