6
configuration. Likewise, consult the instructions packaged
with the thermostat for mounting and location information.
THERMOSTAT
2-STAGE HEATING WITH
2-STAGE COOLING
Two-Stage Thermostat
with Three Low Voltage Wires to
Remote
2
2
2
1
2
1
1
2
Two-Stage Thermostat
with Three Low Voltage Wires to Remote
Overcurrent Protection
The following overcurrent protection devices are approved
for use.
• Time delay fuses
• HACR type circuit breakers
These devices have sufficient time delay to permit the
motor-compressor to start and accelerate its load.
Three Phase Compressor Rotation
CAUTION
Use care when handling scroll compressors. Dome
temperatures could be hot.
Three phase compressors are power phase dependent
and can rotate in either direction.
Verify proper rotation for three phase compressors by
ensuring the suction pressure drops and discharge
pressure rises when the compressor is energized.
NOTE: When operated in reverse, a three phase
scroll compressors is noisier and its current
draw substantially reduced compared to marked
values.
To correct, disconnect power and switch any two leads at
the unit contactor and re-observe.
High Voltage Connections
Route power supply and ground wires through the high
voltage port and terminate in accordance with the wiring
diagram provided inside the control panel cover.
Low Voltage Connections
Condensing unit control wiring requires 24 Volt minimum,
25VA service from the indoor transformer. Low voltage
wiring for two-stage units depends on the thermostat used
and the number of control wires between the indoor unit
and the condensing unit. Route control wires through the
low voltage port and terminate in accordance with the
wiring diagram provided inside the control panel cover.
THERMOSTAT
SINGLE-STAGE HEATING
WITH
SINGLE-STAGE COOLING
Single-Stage Thermostat
with Two Low Voltage Wires to Remote
SYSTEM START UP
CAUTION
POSSIBLE REFRIGERANT LEAK
To avoid a possible refrigerant leak, open the service valves
until the top of the stem is 1/8” from the retainer.
When opening valves with retainers, open each valve
only until the top of the stem is 1/8” from the retainer. To
avoid loss of refrigerant, DO NOT apply pressure to the
retainer. When opening valves without a retainer remove
service valve cap and insert a hex wrench into the valve
stem and back out the stem by turning the hex wrench
counterclockwise. Open the valve until it contacts the rolled
lip of the valve body.
NOTE: These are not back-seating valves. It is not
necessary to force the stem tightly against the
rolled lip.
NOTE: Power must be supplied to the outdoor
units containing ECM motors before the power is
applied to the indoor unit. Sending a low voltage
signal without high voltage power present at
the outdoor unit can cause malfunction of the
control module on the ECM motor.
Adequate refrigerant charge for the matching HSVTC
evaporator coil and 15 feet of lineset is supplied with
the condensing unit. If using evaporator coils other than
HSVTC coil, it may be necessary to add or remove
refrigerant to attain proper charge. If line set exceeds 15
feet in length, refrigerant should be added at .6 ounces per
foot of liquid line.
NOTE: Charge should always be checked using
superheat when using a piston and subcooling
when using TXV equipped indoor coil to verify
proper charge.
Break vacuum by fully opening liquid service valve.
After the refrigerant charge has bled into the system,
open the suction service valve. The service valve cap is
the secondary seal for the valves and must be properly
tightened to prevent leaks. Make sure cap is clean and
apply refrigerant oil to threads and sealing surface on
