Kele UCM-420A User manual

UCM-420A
Setpoint Controller
Operating and
Installation Instructions
April 1994
TM

A LARGE number
of applications in a
SMALL package...
LOCAL SETPOINT
CONTROLLER
UCM-420A
REMOTE SETPOINT
CONTROLLER
REMOTE SETPOINT
CONTROLLER WITH
LOCAL ADJUSTMENT
4-20 mA SIGNAL
GENERATOR
PULSE-WIDTH
TO ANALOG
CONVERTER
OUTPUT EXPANDER
SAMPLE AND HOLD

Section Page
How to Use This Manual ........................................... 2
Features ......................................................................2
Specifications ............................................................ 2
Installation Instructions and Dimensions ................3
General Wiring Instructions ......................................4
General Wiring Diagrams ..........................................4
Modes of Operation - Descriptions
A Remote Setpoint Controller ..............................................8
B Local Setpoint Controller ..................................................9
C Remote Setpoint Controller with Local Adjustment ..........10
D Output Expander (Multiplexed PWM) ...............................11
E Sample and Hold ..............................................................12
F PWM to 4-20 mA Converter (Single Unit or Multiplexed) 12
G 4-20 mA Signal Generator ............................................... 12
Set-up Instructions
A Remote Setpoint Controller ..............................................13
B Local Setpoint Controller ..................................................16
C Remote Setpoint Controller with Local Adjustment...........18
D Output Expander (Multiplexed PWM) ...............................22
E Sample and Hold ..............................................................26
F PWM to 4-20 mA Converter (Single Unit or Multiplexed) 27
G 4-20 mA Signal Generator ............................................... 29
Ordering Information .................................................30
1
About the
UCM-420A
The UCM-420A is a low-cost
microprocessor-based con-
troller that uses industry-stan-
dard 4-20 mA or 1-5 VDC
input/output signals to provide
stand-alone P/I control or output
expansion.
When used as a Stand-Alone
Controller with Local Setpoint,
the UCM-420A provides propor-
tional/integral control of VFDs,
valves, actuators, or any device
that accepts a 4-20 mA or 1-5 VDC
signal. Input may be 4-20 mA,
1-5 VDC, or PreCon Type 3
Thermistor.
When used as a Stand-Alone
Controller with Remote Setpoint
for P/I control, the setpoints
may be adjusted by a 1-5 VDC,
4-20 mA, or pulse-width modu-
lated signal.
When used as a Remote
Setpoint Controller with Local
Adjustment, the remote setpoint
can have 100% control, or can
establish a base setpoint with the
local setpoint having a ±12.5%
adjustment.
When used as an Output
Expander, one AC or DC time-
based PWM signal can control up
to eight groups of UCM-420As
independently. This produces
eight analog outputs from one
PWM controller output. Five
common jumper-selectable time
bases are available.
Table of Contents
KELE
P.O. Box 34817
Memphis, TN 38184
Phone: [phone]
FAX: [phone]

• Proportional / Integral Control
• DIP switch / Jumper Programming
• Sample and Hold for Failsafe
• 6-Hour Memory on Loss of Power
• Selectable Throttling Range
• Selectable Reset Rates
• Selectable Direct- or Reverse-Acting
• 4-20 mA or 1-5 VDC* Output
• 4-20 mA, 1-5 VDC or Thermistor Input
• Selectable Pulse-Width Time Base
• Status LED Indication
• Multiplex Input Operation
• Pulse-Width to 4-20 mA Converter
• Remote and/or Local Setpoint
• Local Setpoint Potentiometer Mounted on
Unit (Standard)
• Optional DIN Rail Mount
• Optional Setpoint Potentiometer on
Stainless Steel Plate
Supply voltage 24 VAC ±10% @ 100 mA (130 mA if PWM input is used) or
24 VDC ±10% @ 50 mA (65 mA if PWM input is used)
Remote setpoint input 4-20 mA, 1-5 VDC, PWM or Multiplexed PWM
Local setpoint input 4-20 mA, 1-5 VDC, three-wire potentiometer or PreCon two-wire potentiometer
PWM time base 0.1-2.65, 5.2, 12.85, 25.6 seconds or 0.59-2.93 seconds
Output 4-20 mA sourcing (1-5 VDC with 250 ohm resistor)
Output resolution 256 steps
Output burden 650 ohm maximum
Input 4-20 mA, 1-5 VDC or PreCon Type 3 Thermistor (thermistor range 50° to 90°F)*
Input impedance 250 ohms (mA)/10,000 ohms (voltage)
Accuracy ±1%
Operating temperature 32° to 158°F (0° to 70°C)
Humidity limit 95% noncondensing
How to Use This Manual
2
The UCM-420A is a very versatile product designed
to cover a wide variety of control applications. To
properly apply the UCM-420A, refer to the MODES
OF OPERATION (beginning on page 8) and select
the configuration you desire for your control system.
Then proceed to the section and page number indi-
cated for the proper application, wiring and set-up of
the UCM-420A.
* Other ranges available
* Requires external 250 ohm resistor
FEATURES
SPECIFICATIONS

INSTALLATION
Mount the UCM-420A using the
mounting tabs on the unit. If pur-
chased with the UCO-47 DIN Rail
Mounting Option, mount on a DIN rail.
The UCM-420A must be installed in a
clean, dry location, avoiding areas of
temperature extremes, corrosive
vapors, or electromagnetic interfer-
ence.
Failure to follow these directions could
result in damage to the UCM-420A or
other connected equipment, as well as
affect the manufacturer's warranty.
MOUNTING
TABS
1.5
(3.81)
4.8
(12.19)
2.9
(7.37) 4.0
(10.16)
3.4
(8.64) 4.6 (11.68)
2.0
(5.08)
SIDE VIEW
TOP VIEW
MOUNTING
SLOTS FOR
OPTIONAL
DIN RAIL
ADAPTER
in
(cm)
Installation and Dimensions
DIN RAIL
MOUNTING
OPTION
3
DIMENSIONS

PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
FEEDBK
INPUT
24V PWR
COMMON
MA SIG
OUTPUT
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
24 VAC
OR
24 VDC
+
–
CONTACT AT BAS CONTROLLER
7
8
9
10
3
4
5
6
4
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
24 VAC
OR
24 VDC
+
–
CONTACT AT BAS CONTROLLER
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
Make all connections according to wiring diagrams and in compliance with national and local codes. Make all con-
nections with power removed. Failure to do so may result in circuit board damage. Shielded cable is recommended
for input and analog setpoint wiring. The shield should be connected to the UCM-420A "common" terminal. At the
opposite end, the shield is not to be connected, and should be taped back. In cases where more wires are required
to be connected to the common terminal block of the UCM-420A than will fit under the screw on the terminal block,
connect as follows:
A. Place the 24 VDC minus power wire directly under the "common" screw.
B. Place one or two short splice wires directly under the "common" screw and tighten screw.
C. Make all required "common" connections to the splice wires using crimp connections or
wire nuts.
Make all wiring connections for local and/or remote setpoint, input, power, and outputs per the General Wiring
Diagrams which follow.
The PWM Remote Setpoint Signal may be powered by the UCM-420A power supply or by a separate power
source. If a separate power source is used, the PWM signal may be 24 VAC or 24 VDC. There is no polarity on the
PWM terminals. Either leg of the PWM signal may be switched by the controller.
(See General Wiring Diagrams 1, 2 & 3.)
REMOTE SETPOINT WIRING - PULSE-WIDTH SETPOINT (DIAGRAMS 1, 2 & 3)
GENERAL WIRING DIAGRAM 1 - Using the UCM-420A power supply for PWM pulse and switching
positive leg of the PWM pulse circuit.
GENERAL WIRING DIAGRAM 2 - Using the UCM-420A power supply for PWM pulse and switching
negative leg of the PWM pulse circuit.
General Wiring
Instructions & Diagrams

5
General Wiring
Diagrams (Cont.)
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
24 VAC
OR
24 VDC
+
–
24 VAC
OR
24 VDC
+
–
CONTACT AT BAS CONTROLLER
(EITHER LEG MAY BE SWITCHED)
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
24 VAC
OR
24 VDC
+
–
+
–4-20 MA REMOTE
SETPOINT SIGNAL
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
24 VAC
OR
24 VDC
+
–
+
–1-5 VDC REMOTE
SETPOINT SIGNAL
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
GENERAL WIRING DIAGRAM 3 - Completely separate PWM and UCM-420A circuits.
REMOTE SETPOINT - ANALOG SETPOINT WIRING (DIAGRAMS 4 & 5)
GENERAL WIRING DIAGRAM 4 - 4-20 mA remote setpoint
GENERAL WIRING DIAGRAM 5 - 1-5 VDC remote setpoint

6
LOCAL SETPOINT WIRING (DIAGRAMS 6-9)
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
1-5 VDC
LOCAL
SETPOINT
SIGNAL
+
–
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
4-20 MA
LOCAL
SETPOINT
SIGNAL
+
–
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
INCREASE SETPOINT
FEEDBK
INPUT
24V PWR
PRECON TWO-WIRE
POTENTIOMETER
("XA" OPTION ON
TEMPERATURE SENSOR)
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
INCREASE SETPOINT
*WHEN A THREE-WIRE POTENTIOMETER
IS USED, JUMPER PLUGS MUST BE LEFT
OFF POSITIONS 3, 4, 5 AND 6. FEEDBK
INPUT
24V PWR
THREE-WIRE
POTENTIOMETER
5 KW TO 50 KW
MAXIMUM
RESISTANCE
RED
GREEN
BLACK
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
GENERAL WIRING DIAGRAM 6 -Using a three-wire potentiometer for local setpoint. (The UCM-420A
is shipped with a three-wire potentiometer mounted and wired per this diagram.)
GENERAL WIRING DIAGRAM 7 - Using a PreCon two-wire potentiometer ("XA" option on a tempera-
ture sensor) for local setpoint.
GENERAL WIRING DIAGRAMS 8 & 9 - Using an analog (4-20 mA or 1-5 VDC) signal for local setpoint.
Analog signals are normally used as remote setpoints. However, the UCM-420A may be configured to
accept an analog signal for a local setpoint if this is required.
GENERAL WIRING DIAGRAM 8 -
4-20 mA local setpoint GENERAL WIRING DIAGRAM 9 -
1-5 VDC local setpoint
General Wiring
Diagrams (Cont.)

PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
1
2
3
4
5
6
7
8
9
10
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
24 VAC
OR
24 VDC
+
–
–
+
CONTROLLED
DEVICE
FEEDBK
INPUT
24V PWR
7
General Wiring
Diagrams (Cont.)
INPUT WIRING (DIAGRAMS 10-12)
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
TWO-WIRE
4-20 MA
DEVICE
– +
+ –
24 VDC
POWER
SUPPLY
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
1-5 VDC
INPUT
SIGNAL
+
–
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
PRECON TYPE 3
THERMISTOR
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
COMMON
MA SIG
OUTPUT
FOUR-WIRE
4-20 MA
DEVICE
+ +
+ –
24 VDC
POWER
SUPPLY
– –
FEEDBK
INPUT
24V PWR
1
2
11
12
JUMPER
POSITION
NUMBER
JUMPER
PINS
7
8
9
10
3
4
5
6
GENERAL WIRING DIAGRAM 10 -
PreCon Type 3 Thermistor input
GENERAL WIRING DIAGRAM 11B -
4-20 mA input from a four-wire device
POWER SUPPLY & OUTPUT WIRING (DIAGRAM 13)
GENERAL WIRING DIAGRAM 13 - Power supply and output wiring
GENERAL WIRING DIAGRAM 11A -
4-20 mA input from a two-wire device
GENERAL WIRING DIAGRAM 12 -
1-5 VDC input signal

8
The UCM-420A is a versatile, low-cost microprocessor-based proportional/integral con-
troller which may be used for a wide variety of control applications.
To select the mode of operation required, please review the descriptions on the following
pages.
EXAMPLE: REMOTE SETPOINT CONTROLLER - Hot Water Reset
In this example, a BAS controller is monitoring outdoor air temperature and sending a time-based pulse-
width signal to the UCM-420A to set the system hot water temperature. By using this control system, the
BAS may also control the hot water temperature based on time of day, minimum space temperature, etc.
The UCM-420A accepts the setpoint signal from the BAS and the input from the hot water temperature
sensor and sends a proportional/integral control signal to the three-way valve to maintain the system hot
water temperature as programmed.
HOT WATER
RESET VALVE
4-20 MA P/I
CONTROL SIGNAL
UCM-420A
HOT WATER SUPPLY
FROM BOILER
PWM REMOTE SETPOINT SIGNAL
4-20 MA TEMPERATURE
INPUT SIGNAL
BAS
CONTROLLER
RTD &
TRANSMITTER
HOT WATER
SUPPLY
TO SYSTEM
HOT WATER
RETURN
FROM SYSTEM
ARemote Setpoint Controller
When the UCM-420A is used as a remote setpoint controller, a 4-20 mA, 1-5 VDC or time-based pulse-width signal
from a BAS controller sends a setpoint signal to the UCM-420A. The UCM-420A monitors a 4-20 mA, 1-5 VDC, or
thermistor input from the process being controlled to provide a proportional/integral control signal to the controlled
device. This signal may be direct- or reverse-acting. See page 13 for instructions on operating the UCM-420A in
this mode.
Modes of Operation

VFD UCM-420A
T30-030
AC POWER
IN
STATIC
PRESSURE
TUBING
4-20 MA
P/I
CONTROL
SIGNAL
SUPPLY
AIR
RETURN
AIR VAV TERMINAL
VAV TERMINAL
VAV TERMINAL
9
When the UCM-420A is used as a local setpoint controller, the potentiometer mounted on the unit may control the
setpoint. If this is not desired, a UCM-SPA setpoint potentiometer or PreCon "XA" Setpoint Option on a tempera-
ture sensor may be wired to the "Local Setpoint" terminals as shown in the wiring diagrams. (The local setpoint may
also be configured to accept a 4-20 mA or 1-5 VDC signal, although these signals would normally be used as a
remote setpoint). A 4-20 mA, 1-5 VDC, or thermistor input (with a range of 50 to 90°F)* from the process being con-
trolled allows the UCM-420A to monitor the system and provide a proportional/integral, direct- or reverse-acting
signal to the device being controlled. See page 16 for instructions on operating the UCM-420A in this mode.
*Other ranges available
Local Setpoint Controller
Modes of Operation (Cont.)
EXAMPLE: LOCAL SETPOINT CONTROLLER - Static Pressure Control
In this example, the input to the UCM-420A is a 4-20 mA signal from a pressure transducer that monitors duct pres-
sure. The setpoint is adjusted by using the setpoint potentiometer mounted on the UCM-420A. The UCM-420A then
sends a 4-20 mA control signal to the VFD which controls the AHU fan speed, which in turn, determines duct pres-
sure.
B

SUPPLY
AIR
VAV
TERMINAL
BAS
CONTROLLER
UCM-420A
4-20 MA P/I
CONTROL
SIGNAL
ST-S3E-XA
TEMPERATURE SENSOR
WITH SETPOINT ADJUST
THERMISTOR
TEMP INPUT
LOCAL SETPOINT
ADJUST
4-20 MA REMOTE
SETPOINT SIGNAL
ACT.
SUPPLY
AIR
10
Remote Setpoint Controller With Local Adjustment
C
When the UCM-420A is used as a remote setpoint controller with local adjustment, a 4-20 mA, 1-5 VDC, or time-
based pulse-width signal from a BAS controller sends a setpoint signal to the UCM-420A. The setpoint poten-
tiometer on the UCM-420A or a UCM-SPA setpoint potentiometer wired to the "Local Setpoint" terminals may then
be used to adjust the setpoint ±12.5% of the input range, or a PreCon "XA" Setpoint Option on a temperature
sensor may be used as a local setpoint and may adjust the setpoint ±9.4% of the input range. (A 4-20 mA or 1-5 VDC
signal may also be used as the "Local Setpoint" signal, although these are normally remote setpoint signals. When
these are used as local setpoints in this mode, they have the authority to adjust the setpoint ±12.5% of the input
range.) A 4-20 mA, 1-5 VDC, or thermistor input (with a range of 50 to 90°F)* from the process being controlled
allows the UCM-420A to monitor the system and provide a proportional/integral, direct- or reverse-acting signal to
the device being controlled. See page 18 for instructions on operating the UCM-420A in this mode.
* Other ranges available
EXAMPLE: REMOTE SETPOINT CONTROLLER WITH LOCAL ADJUSTMENT - VAV Control
In this example, a PreCon ST-S3E-XA Thermistor with setpoint adjustment is located in the space being con-
trolled. The setpoint is a 4-20 mA signal from a BAS controller. The PreCon "XA" setpoint adjuster will have
authority to adjust the setpoint ±3.76°F. [(90 to 50°F*) x 0.094 = 3.76°F] In this example, the BAS controller could
be programmed to send a setpoint signal for 72°F (12.8 mA) during the day, 82°F (16.8 mA) at night, etc.
Modes of Operation (Cont.)

11
Modes of Operation (Cont.)
SUPPLY
AIR
VAV
TERMINAL
ACT.
SUPPLY
AIR
UCM-420A
ST-S3P
SUPPLY
AIR
VAV
TERMINAL
ACT.
SUPPLY
AIR
UCM-420A
ST-S3P
SUPPLY
AIR
VAV
TERMINAL
ACT.
SUPPLY
AIR
UCM-420A
ST-S3P
TEMPERATURE
SENSOR
4-20 MA P/I
CONTROL
SIGNAL
+
–
CONTROLLER
N.O. PWM
CONTACT
In this example, one time-based
pulse-width output from a BAS con-
troller is used to send a setpoint
signal to three UCM-420A setpoint
controllers. Each of these may have
a different setpoint. Each UCM-420A
also accepts an input from a PreCon
Type 3 Temperature Sensor in the
space being controlled. The
UCM-420As send 4-20 mA propor-
tional/integral control signals to the
VAV terminals so that the input
matches the setpoint. Multiple
UCM-420As may be assigned the
same address so that they have the
same setpoint. Eight different
addresses are available so that up to
eight groups of UCM-420As may be
controlled by one BAS output.
Instructions on setting UCM-420A
addresses and how to update the
setpoint with the BAS pulse-width
signal are on page 22.
EXAMPLE: UCM-420As USED AS OUTPUT EXPANDERS - Multiplexed VAV Control
The UCM-420A may be operated in a multiplexed pulse-width modulation mode so that one BAS output may control
up to eight groups of UCM-420As with each group able to have a different setpoint. When operated in this mode,
each UCM-420A accepts a 4-20 mA, 1-5 VDC, or thermistor input (with a range of 50 to 90°F)* from the process
being controlled. The "PWM INPUT" terminals are wired to the normally open contacts on a BAS controller. The
BAS controller is programmed to send a series of 24 VAC or 24 VDC time-based pulse-width signals to the
UCM-420As. These PWM signals select which units are to be addressed, and adjust their setpoints as required.
The UCM-420As which are not being addressed ignore the new setpoint signal and continue to control based on
their previous setpoint. Each UCM-420A will monitor its input signal and send a P/I control signal to the controlled
device to maintain the required setpoint. When operated in this mode, the local setpoint may also be used to adjust
the setpoint which has been set by the BAS controller. The setpoint potentiometer on the UCM-420A or a UCM-
SPA setpoint potentiometer wired to the "Local Setpoint" terminals may be used to adjust the setpoint ±12.5% of the
input range, or a PreCon "XA" Setpoint Option on a temperature sensor may be used as a local setpoint and may
adjust the setpoint ±9.4% of the input range. (A 4-20 mA or 1-5 VDC signal may also be used as the "Local
Setpoint" signal, although these are normally remote setpoint signals. When these are used as local setpoints in this
mode, they have the authority to adjust the setpoint ±12.5% of the input range.) See page 22 for instructions on
operating the UCM-420A in this mode. * Other ranges available
DOutput Expander (Multiplexed PWM)

12
If the device to be controlled by the UCM-420A needs to be calibrated before the system is started up, the UCM-420A
may be used to generate a 4-20 mA output signal in 1 mA steps. In this mode the UCM-420A ignores all input and
setpoint signals and outputs a signal from 4-20 mA when DIP switches are turned off or on as required. See Page
29 for instructions on operating the UCM-420A in this mode.
THIS CONCLUDES MODES OF OPERATION. THE FOLLOWING SET-
UP INSTRUCTIONS WILL GUIDE YOU THROUGH THE STEPS NEC-
ESSARY TO ACHIEVE THE MODE OF OPERATION YOU REQUIRE.
ESample and Hold
The UCM-420A may be used to monitor and pass through a 4-20 mA or 1-5 VDC signal. If the signal being moni-
tored is lost, the UCM-420A will output the last valid value for the signal until the signal returns. On a power loss, the
signal is remembered up to six hours. When used in this mode the UCM-420A may be programmed to either
reverse the signal being monitored, or pass it through direct. See page 26 for instructions on operating the UCM-420A
in this mode.
FPulse-Width to 4-20 mA Converter (Single or Multiplexed)
G4-20 mA Signal Generator
In this mode the UCM-420A converts a time-based pulse-width AC or DC signal to a 4-20 mA output. By using the
multiplexed mode, multiple UCM-420As may be controlled by one BAS output. In this mode all setpoint and input
signals are ignored and the output signal is based on the pulse-width signal only. The output signal is retained up to
6 hours on a loss of power. Upon a power return, the saved value is output until a new pulse signal is received. The
output may be direct- or reverse-acting. See page 27 for instructions on operating the UCM-420A in this mode.
Modes of Operation (Cont.)

If remote setpoint is set for pulse-width modulation, select the pulse-width time base from
TABLE 2. If remote setpoint is by 4-20 mA or 1-5 VDC, proceed to Step A-3.
Mode Switch Switch Switch Switch Set jumper
A1 A2 B1 B2 plugs on
4-20 mA Remote setpoint ON OFF OFF OFF Position 1
1-5 VDC Remote setpoint ON OFF OFF OFF Position 2
PWM Remote setpoint
(no multiplex mode) ON OFF ON OFF Position 1
13
Set-Up Instructions
ASET-UP OF THE UCM-420A AS A REMOTE SETPOINT
CONTROLLER (SEE PAGE 8)
Set the DIP switches and jumpers as shown in TABLE 1 for the remote setpoint to be used.
FAILSAFE FEATURE
On a loss of power, the remote setpoint value is retained for up to 6 hours. Upon power return on a unit with
PWM remote setpoint, the saved value will be used for control until a new PWM pulse is received.
Upon power return on a unit with analog remote setpoint, the saved value will be used to control until a new
analog setpoint signal is received.
If power is not lost, but the analog remote setpoint signal is suddenly lost (because of a loose wire or
Building Automation System failure), the UCM-420A will continue to control with the previous setpoint until a
valid signal returns.
STEP
A-2
Time base B6 B7 B8
0.1-2.65 seconds OFF OFF OFF
0.1-5.2 seconds OFF OFF ON
0.1-12.85 seconds OFF ON OFF
0.1-25.6 seconds OFF ON ON
0.59-2.93 seconds ON OFF OFF
STEP
A-1
Setpoint = (pulse length) (input range) + input lower value
time base
Example: If pulse length is 12.8 sec., time base is 25.6 sec., and the input sensor has a 4-20 mA range of
20° to 120°F, the setpoint could be determined as follows: Setpoint = (12.8) (120-20) + 20 = 70.2°F
(25.6 - 0.1)
TABLE 2
TABLE 1

Throttling Range Switch A6 Switch A7 Switch A8
10% OFF OFF OFF
20% OFF OFF ON
35% OFF ON OFF
50% OFF ON ON
65% ON OFF OFF
80% ON OFF ON
90% ON ON OFF
100% ON ON ON
Input Set jumper plugs on
4-20 mA Positions 7 and 11
1-5 VDC Positions 8 and 11
PreCon Type 3 Thermistor Positions 10 and 12
14
Select the type of input to be used and set the jumper per TABLE 3. The input may be a 4-20 mA
or 1-5 volt signal that measures temperature, pressure, humidity, etc., or a PreCon Type 3
Thermistor. If the thermistor is used, the range of the thermistor is 50° to 90°F.*
*Other ranges available
STEP
A-3
TABLE 3
TABLE 4
Set switch A3 in the "ON" position for Direct-Acting Control and in the "OFF" position for
Reverse-Acting Control. ( Direct-Acting Control is when an increase in the input signal above set-
point causes the output signal to increase. Reverse-Acting Control is when an increase in the input
signal above setpoint causes the output signal to decrease.)
STEP
A-4
Set the proportional throttling range per TABLE 4. The throttling range is the amount of signal
change at the input required to cause the output signal to go through its entire range (4-20 mA).
For example, a 20% throttling range means that a 1 mA change in the input causes a 5 mA change
in the output signal. When using the optional thermistor input, a 1°F change in input is the equiva-
lent of 0.4 mA change in the mA input mode. The correct throttling range cannot be calculated, but
must be adjusted for each application. Generally, systems that respond quickly should have a nar-
rower throttling range than systems that respond slowly.
STEP
A-5
Set-Up Instructions (Cont.)

Resets/Minute Switch A4 Switch A5
Reset OFF OFF OFF
0.5 Resets/Minute OFF ON
1 Resets/Minute ON OFF
2 Resets/Minute ON ON
15
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
FEEDBK
INPUT
24 PWR
COMMON
MA SIG
OUTPUT
1
2
3
4
5
6
7
8
9
10
11
12
B3
0
0
0
0
1
1
1
1
B6
0
0
0
0
1
B7
0
0
1
1
X
B8
0
1
0
1
X
B4
0
0
1
1
0
0
1
1
B5
0
1
0
1
0
1
0
1
MUX
ADDR
1
2
3
4
5
6
7
8
A6
0
0
0
0
1
1
1
1
A7
0
0
1
1
0
0
1
1
A8
0
1
0
1
0
1
0
1
PROP
T.R.
10%
20%
35%
50%
65%
80%
90%
100%
UCM-420A
TIME
BASE
2.65
5.2
12.85
25.6
.59-2.93
A4
0
0
1
1
A5
0
1
0
1
RESET
PER MIN
OFF
0.5
1
2
"1" MEANS
TURN SWITCH ON "0" MEANS TURN SWITCH OFF
SWITCH OFF SWITCH ON
A3
A2
A1
B1
B2
REVERSE ACTING
BOTH OFF >> REMOTE SETPT
SAMPLE AND HOLD MODE
BOTH OFF >> ANALOG
REMOTE SETPOINT
DIRECT ACTING
LOCAL SETPT ENABLE
REMOTE SETPT ENABLE
PWM REM SETPT SGLE UNIT
PWM REM SETPT MUX MODE
LOCAL SETPOINT
FEEDBACK REMOTE
SETPOINT
STATUS
B
A1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
24 VAC OR 24 VDC POWER
4-20 MA, 1-5 VOLT OR THERMISTOR INPUT SIGNAL
4-20 MA SOURCING OUTPUT SIGNAL TO
CONTROLLED DEVICE
4-20 MA OR 1-5 VOLT REMOTE SETPOINT SIGNAL
(ONLY IF REMOTE SETPOINT IS ANALOG SIGNAL)
24 VAC OR 24 VDC PWM SIGNAL FROM BAS
(ONLY IF REMOTE SETPOINT IS PWM)
CONTACT AT CONTROLLER*
+
–
+
–
–
+
+
–
+
–
Steady Green - Power On
Dark - Power Loss
Steady Red - PWM Signal Present
WIRING THE UCM-420A AS A REMOTE SETPOINT CONTROLLER
Set the integral reset rate per TABLE 5. The integral reset feature corrects the output of the
UCM-420A to compensate for the offset inherent in proportional-only controllers. The integral reset
ramps the output in the direction that forces the input signal to exactly match the setpoint. The
number of times per minute this offset is overcome by the output signal is the integral reset rate. If
the output of the UCM-420A is used for digital control, set the integral reset "OFF."
STEP
A-6
Set-Up Instructions (Cont.)
TABLE 5
THIS CONCLUDES SET-UP OF THE UCM-420A AS A REMOTE SET-
POINT CONTROLLER. WIRE THE UCM-420A PER THE WIRING
DIAGRAM BELOW AND PER GENERAL WIRING DIAGRAMS.
LED INDICATION
*NOTE: PWM contact at controller may switch either positive or negative leg of circuit, and PWM
circuit may use the same power supply as the UCM-420A, or a separate power supply. See the
General Wiring Diagram Section for detailed wiring.

Input Set jumper plugs on
4-20 mA Positions 7 &11
1-5 VDC Positions 8 & 11
PreCon Type 3 Thermistor Positions 10 & 12
Mode Switch Switch Set jumper
A1 A2 plugs on
Three-wire pot Local setpoint OFF ON Position 1 (No jumper on 3-6)
4-20 mA* Local setpoint OFF ON Positions 1 & 3
1-5VDC* Local setpoint OFF ON Positions 1 & 4
Two-wire pot* Local setpoint OFF ON Positions 1 & 6
16
BSET-UP OF THE UCM-420A AS A LOCAL SETPOINT
CONTROLLER (SEE PAGE 9)
Set the DIP switches and jumpers as shown in TABLE 6 for the local setpoint to be used.
STEP
B-1
TABLE 6
TABLE 7
*UCM-420A comes from the factory with an integral three-wire local setpoint potentiometer. To use any
other local setpoint option, installer must first remove existing three wires from local setpoint terminals on
UCM-420A terminal block.
Select the type of input to be used and set the jumpers per TABLE 7. The input may be a 4-20 mA
or 1-5 volt signal which measures temperature, pressure, humidity, etc. or a PreCon Type 3
Thermistor. If the thermistor is used, the range of the thermistor input is 50 to 90°F.*
*Other ranges available
STEP
B-2
Set switch A3 in the "ON" position for Direct-Acting Control and in the "OFF" position for
Reverse-Acting Control. ( Direct-Acting Control is when an increase in the input signal above set-
point causes the output signal to increase. Reverse-Acting Control is when an increase in the input
signal above setpoint causes the output signal to decrease.)
STEP
B-3
Set the proportional throttling range per TABLE 8. The throttling range is the amount of signal
change at the input required to cause the output signal to go through its entire range (4-20 mA).
For example, a 20% throttling range means that a 1 mA change in the input causes a 5 mA change
in the output signal. When using the optional thermistor input, a 1°F change in input is the equiva-
lent of 0.4 mA change in the mA input mode. The correct throttling range cannot be calculated, but
must be adjusted for each application. Generally, systems that respond quickly should have a nar-
rower throttling range than systems that respond slowly.
STEP
B-4
Set-Up Instructions (Cont.)

LOC SPT POT +
LOC SPT INPUT
LOC SPT POT –
THREE-WIRE POTENTIOMETER
(5KWTO 50 KW)
LOCAL SETPOINT
(FACTORY INSTALLED
ON BASIC MODEL)
INCREASE SETPONT
LOC SPT POT +
LOC SPT INPUT
LOC SPT POT – TWO-WIRE POTENTIOMETER
LOCAL SETPOINT
("XA OPTION ON
PRECON THERMISTOR)
INCREASE
SETPONT
LOC SPT POT +
LOC SPT INPUT
LOC SPT POT – 4-20 MA OR 1-5 VOLT
LOCAL SETPOINT
+
–
COMMON
COMMON
Resets/Minute Switch A4 Switch A5
Reset OFF OFF OFF
0.5 Resets/Minute OFF ON
1 Resets/Minute ON OFF
2 Resets/Minute ON ON
Throttling Range Switch A6 Switch A7 Switch A8
10% OFF OFF OFF
20% OFF OFF ON
35% OFF ON OFF
50% OFF ON ON
65% ON OFF OFF
80% ON OFF ON
90% ON ON OFF
100% ON ON ON
17
PWM
INPUT
PWM
INPUT
REM SPT
INPUT
LOC SPT
POT +
LOC SPT
INPUT
LOC SPT
POT –
FEEDBK
INPUT
24 PWR
COMMON
MA SIG
OUTPUT
1
2
3
4
5
6
7
8
9
10
11
12
LOCAL SETPOINT
FEEDBACK REMOTE
SETPOINT
STATUS
B
A
24 VAC OR 24 VDC POWER
4-20 MA, 1-5 VOLT OR THERMISTOR INPUT SIGNAL
4-20 MA SOURCING OUTPUT SIGNAL TO
CONTROLLED DEVICE
+
–
–
+
+
–
SEE
LOCAL
SETPOINT
WIRING
OPTIONS
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
WIRING THE UCM-420A AS A LOCAL SETPOINT CONTROLLER LOCAL SETPOINT WIRING OPTIONS
Steady Green - Power On
Dark - Power Loss
LED INDICATION
TABLE 8
Set the integral reset rate per TABLE 9. The integral reset feature corrects the output of the
UCM-420A to compensate for the offset inherent in proportional-only controllers. The integral reset
ramps the output in the direction that forces the input signal to exactly match the setpoint. The
number of times per minute this offset is overcome by the output signal is the integral reset rate. If
the output of the UCM-420A is used for digital control, set the integral reset rate "OFF."
STEP
B-5
TABLE 9
THIS CONCLUDES SET-UP OF THE UCM-420A AS A LOCAL SETPOINT CON-
TROLLER. WIRE THE UCM-420A PER THE WIRING DIAGRAM BELOW AND
PER GENERAL WIRING DIAGRAMS.
Set-Up Instructions (Cont.)

Setpoint = (pulse length) (input range) + input lower value
time base
Example: If pulse length is 12.8 sec., time base is 25.6 sec., and the input sensor has a 4-20 mA range of
20 to 120°F, the setpoint could be determined as follows: Setpoint = (12.8) (120-20) + 20 = 70.2°F
(25.6 - 0.1)
Time base Switch B6 Switch B7 Switch B8
0.1-2.65 seconds OFF OFF OFF
0.1-5.2 seconds OFF OFF ON
0.1-12.85 seconds OFF ON OFF
0.1-25.6 seconds OFF ON ON
0.59-2.93 seconds ON OFF OFF
18
CSET-UP OF THE UCM-420A AS A REMOTE SETPOINT
CONTROLLER WITH LOCAL ADJUSTMENT (SEE PAGE 10)
Set Switch A1 and Switch A2 both in the "ON" position.
STEP
C-1
Set the DIP switches and jumpers as shown in TABLE 10 for the remote setpoint to be used.
STEP
C-2
Remote Setpoint Signal Switch B1 Switch B2 Set jumper plugs on
4-20 mA OFF OFF Position 1
1-5 VDC OFF OFF Position 2
PWM ON OFF Position 1
TABLE 10
TABLE 11
FAILSAFE FEATURE
On a loss of power the remote setpoint value is retained for up to 6 hours. Upon power return on a unit with
PWM remote setpoint, the saved value will be used for control until a new PWM pulse is received. Upon
power return on a unit with analog remote setpoint, the saved value will be used to control until a new
analog setpoint signal is received. If power is not lost, but the analog remote setpoint signal is suddenly lost
(because of a loose wire or Building Automation System failure) the UCM-420A will continue to control with
the previous setpoint until a valid signal returns.
If Remote Setpoint is set for Pulse-Width Modulation, select the pulse-width time base from
TABLE 11. If remote setpoint is by 4-20 mA or 1-5 VDC, proceed to Step C-4.
STEP
C-3
Set-Up Instructions (Cont.)