Manual 2100-537
I
Page 22 of 54
WIRING INSTRUCTIONS
GENERAL
All wiring must be installed in accordance with the
National Electrical Code and local codes. In Canada, all
wiring must be installed in accordance with the Canadian
Electrical Code and in accordance with the regulations of
the authorities having jurisdiction. Power supply voltage
must conform to the voltage shown on the unit serial plate.
A wiring diagram of the unit is attached to the inside of the
electrical cover. The power supply shall be sized and fused
according to the specications supplied. A ground lug is
supplied in the control compartment for equipment ground.
The unit rating plate lists a “Maximum Time Delay Fuse”
or “HACR” type circuit breaker that is to be used with the
equipment. The correct size must be used for proper circuit
protection and also to assure that there will be no nuisance
tripping due to the momentary high starting current of the
compressor motor.
CONTROL CIRCUIT WIRING
The minimum control circuit wiring gauge needed to insure
proper operation of all controls in the unit will depend on
two factors.
1. The rated VA of the control circuit transformer.
2. The maximum total distance of the control circuit
wiring.
Table 6 should be used to determine proper gauge of control
circuit wiring required.
For low voltage connections, see Figure #6. There are
multiple options based upon the type of installation in
regards to low voltage electrical connections and what
options are selected. These options include a motorized
valve or motorized valve with end switch for ground water
applications, and optional electric duct heater connections.
NOTE: Review the “lettered triangles” and the
corresponding notes on the lower right-hand corner of
Figure #6. When options are not used, the wires will need
attached to the reference points accordingly.
Example: 1. Control Circuit transformer rated at 50 VA
2. Maximum total distance of control circuit
wiring 85 feet.
From Table 7 minimum of 16 gauge wire should be used in
the control circuit wiring.
WALL THERMOSTAT SELECTION
The wall thermostat selection is important in that it needs to
be minimally 2-stage heat and 2-stage cool for applications
without electric heat.
For applications with electric heat, the thermostat will need
to minimally be 3-stage heat and 2-stage cool. The second
bank of electric heat (when equipped) should be wired
through a secondary relay for operation only in Emergency
Heat Mode, at which point compressor operation should be
disabled.
Refer to Figure 6 on the following page for typcial
thermostat connections.
Low Voltage Connection
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.
“R” terminal is 24 VAC hot.
“C” terminal is 24 VAC grounded.
“G” terminal is the fan input.
“Y1” terminal is the compressor part load input.
“Y2” terminal is the compressor full load input.
“O” terminal is the reversing valve input. The reversing
valve must be energized for cooling mode.
“L” terminal is the check light output/compressor lockout.
This terminal is activated on high pressure switch, low
pressure switch, condensate overow, or freeze stat trip.
This is a 24 VAC output.
“W1” terminal is rst stage electric heat input. (If
equipped.)
“E” terminal is the emergency heat input. This energizes
the emergency heat relay, and should be utilized to limit
the amount of electric heat with the geothermal heat pump
operational to limit outlet air temperature.
“W2” terminal is the second stage electric heat input. (If
equipped.)
TABLE 7
CONTROL CIRCUIT WIRING
Rated VA of
Control Circuit
Transformer
Transformer
Secondary
FLA @ 24V
Maximum Total
Distance of Control
Circuit Wiring in Feet
50 2.1
20 gauge - 45
18 gauge - 60
16 gauge - 100
14 gauge - 160
12 gauge - 250
