Figure 2.2 Wall-Mount Unit Control Board - Bard D25A2PA Installation And Service Instructions Manual

• If conditions outside are not conducive to free
cooling, the control board will send:
1. 24VAC signal from N02 to CCM (Compressor)
2. 24VDC from terminal N07 (Blower Motor Start
Relay)
3. 0-10VDC signal from Y1 (Speed Voltage)
Heating Call
When a call for heating generates from the controller,
the control board will send:
1. 24VAC signal from terminal N04 to heat strip
contactor.
2. 24VDC from terminal N07 (Blower Motor Start
Relay)
3. 0-10VDC signal from terminal Y1 (Motor Speed)
High Pressure/Comp Control Module
0-10VDC Indoor Blower Speed Signal
2-10VDC Free-Cooling Damper Signal
24VDC from 48VDC-24VDC Converter
24VDC Output to Blower Motor Start Relay
FIGURE 2.2
Wall-Mount Unit Control Board
Power Loss Relay
Dirty Filter Switch
Low Pressure Switch
Common
Damper Blade Switch
Common
Common
24VAC Heating Output
24VAC Input
Loss of Utility Power
When AC power is lost to the unit (no shore power,
no generator), the AC power loss relay will send a
digital input to terminal DI 1, alerting the board. If
the temperature outside is warmer than the shelter
internal temperature, the units will remain static. If
the temperature outside is cooler than the internal
temperature and there is a generated cooling call, the
control board will send:
1. 2-10VDC Signal from terminal Y2 (Damper Signal)
- Modulates damper to achieve 55°F at supply
air temperature sensor
2. 24VDC from terminal N07 (Blower Motor Start
Relay)
3. 0-10VDC signal from terminal Y1 (Motor Speed)
24VDC to OA Humidity Sensor
Ground
Freezestat Sensor 10kΩ
OA Hum Sensor 4-20mA
RA Temp Sensor 10kΩ
OA Temp Sensor 10kΩ
Supply Air Sensor 10kΩ
– Communication Wire
+ Communication Wire
24VAC Input
24VAC Compressor Output
–24VDC from Power Converter
+24VDC from Power Converter
Manual 2100-643C
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