Table of Contents
Advertisement
18 | Electrical
Safety Devices and the UPM Controller
1
2
3
4
5
17
15
7
Figure # 47
[1] Board Power Indicator
[2] UPM Status LED Indicator
[3] Water Coil Freeze Protection Temperature Selection
[R30]
[4] Air Coil Freeze Protection Temperature Selection
[5] UPM Board Settings
[6] Water Coil Freeze Connection (Freeze 1)
[7] Air Coil Freeze Connection (Freeze 2)
[8] LCD Unit Display Connection
[9] 24VAC Power Input
[10] Compressor Contact Output
[11] High Pressure Switch Connection
[12] Call for Compressor Y1
[13] Low Pressure Switch Connection
[14] 24VAC Power Common
[15] Condensate Overflow Sensor
[16] Dry Contact
[17] UPM Ground Standoff
If the unit is being connected to a thermostat with a
malfunction light, this connection is made at the unit
malfunction output or relay. Refer to Figure #46
If the thermostat is provided with a malfunction light
powered off of the common (C) side of the
transformer, a jumper between "R" and "COM"
terminal of "ALR" contacts must be made.
8733942411 (2017/07)
11
13
12
Each unit is provided with a factory installed Unit
Protection Module that controls the compressor
operation and monitors the safety controls that protect
the unit.
Safety controls include the following:
•
•
10
9
•
Subject to change without prior notice
If the thermostat is provided with a malfunction light
powered off of the hot (R) side of the transformer,
then the thermostat malfunction light connection
should be connected directly to the (ALR) contact on
the unit's UPM board.
High pressure switch located in the refrigerant
discharge line and wired across the HPC terminals
on the UPM.
Low pressure switch located in the unit refrigerant
suction line and wired across terminals LPC1 and
LPC2 on the UPM.
UPM Board Dry Contacts are Normally Open (NO)
Water side freeze protection sensor, mounted close
to condensing water coil, monitors refrigerant
temperature between condensing water coil and
thermal expansion valve. If temperature drops
below or remains at freeze limit trip for 30 seconds,
the controller will shut down the compressor and
enter into a soft lockout condition. The default
freeze limit trip is 26°F, however this can be
changed to 15°F by cutting the R30 or Freeze1
resistor located on top of DIP switch SW1 (Refer to
Figure #47, item [3] for resistor location), Refer to
Figure #48 for sensor location.
Figure # 48
SM Series Heat Pump
SM Series Heat Pump
Advertisement
Table of Contents
