low voltage connections
These units use a grounded 24 volt AC low voltage circuit and require at least a 2 stage heating and a 2 stage cooling thermostat.
“G” terminal is the fan input.
“Y” terminal is the compressor Stage 1 input. “Y1” terminal is the compressor Stage 2 input.
“B” terminal is the reversing valve input. The reversing valve must be energized for heating mode.
“R” terminal is 24 VAC hot.
“C” terminal is 24 VAC grounded.
“L” terminal is compressor lockout output. This terminal is activated on a high or low pressure trip by the electronic heat pump control. This is a 24 VAC output.
“W2” terminal is second stage heat (if equipped).
“O1” terminal is the ventilation input. This terminal energizes any factory or field installed ventilation option.
“DH” terminal is the dehumidifier input. This terminal energizes the factory or field installed dehumidifier option.
“E” terminal is the emergency heat input. This terminal energizes the emergency heat relay if equipped.
NOTE: For total and proper control using DDC, a minimum of 8 controlled outputs are required (6 if no ventilation or dehumidifier option
is installed). For proper system operation under Emergency Heat conditions where the compressor needs to be deactivated, the
low voltage connections
for ddc control
START UP
These units require
application:
1.Use separate service and manufacturing equipment to avoid cross contamination of oil and refrigerants.
2.Use recovery equipment rated for
3.Use manifold gauges rated for
4.
5.
6.
7.
8.
9.Polyol Ester oil is hygroscopic; it will rapidly absorb moisture and strongly hold this moisture in the oil.
10.A liquid line dryer must be used - even a deep vacuum will not separate moisture from the oil.
11.Limit atmospheric exposure to 15 minutes - Maximum.
12.If compressor removal is necessary, always plug compressor immediately after removal. Purge with small amount of nitrogen when inserting plugs.
Fan Only | Energize G | ||
Cooling Mode 1st Stage | Energize Y, G | ||
Cooling Mode 2nd Stage | Energize Y, Y1, G | ||
Heat Pump Heating 1st Stage | Energize Y, G, B | ||
Heat Pump Heating 2nd Stage | Energize Y, Y1, G, B | ||
3rd Stage Heating | Energize G, W2, Y, B, Y1 | ||
w/Heat Pump (if employed) |
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Ventilation | Energize G, O1 | ||
Dehumidifier | Energize DH | ||
Emergency Heat | Energize B, W2, E, G | ||
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Manual |
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