20
START UP & ADJUSTMENTS
Pre-Start Check List
√
Verify the unit is level and allows proper condensate
drainage.
√
Verify all clearance requirements are met and there is
free airflow to and from the outdoor coil.
√
Verify that the duct work is sealed to prevent air leakage.
√
Verify that the line voltage power leads are securely
connected and the unit is properly grounded.
√
Verify that the low voltage wires are securely connected
to the correct leads on the low voltage terminal strip.
√
Verify that the gas line service pressure does not exceed
10.0 inches WC (0.36 psig), and is not less than 4.5
inches WC (0.16 psig) for natural gas. For LP gas the
line service pressure must not exceed 14 inches WC
(0.51 psig) and must not be less than 11.0 inches WC
(0.40 psig).
√
Verify that the flame roll-out control is closed. If necessary,
press the red button to reset the control.
DO NOT
install
a jumper wire across the control to defeat its function.
If the control reopens upon start-up,
DO NOT
reset
the control without identifying and correcting the fault
condition which caused the control to trip.
√
Verify that the gas line has been purged and all
connections are leak tight.
√
Verify that all exterior panels are replaced and securely
fastened.
√
Verify that the outdoor fan turns freely.
√
Verify that the power supply branch circuit overcurrent
protection is sized properly.
√
Verify that the thermostat is wired correctly. The
thermostat function switch should be set to OFF and
the thermostat fan switch should be set to AUTO.
Start-Up Procedure
WARNING:
If this unit is equipped with crankcase heaters,
allow 24 hrs for heating of the refrigerant
compressor crankcase prior to start up and
anytime the power has been removed for more
than 12 hrs. Failure to comply may result in
damage or cause premature failure of the system.
• Check all electrical wiring for loose connections and
tighten as required.
• Check unit for return air filters and condensate trap.
• Close all electrical disconnects to energize the system.
Air Circulation
Leave the thermostat system mode on OFF, and set the
fan mode to ON. Blower should run continuously. Check
the air delivery at the supply registers and adjust register
openings for balanced air distribution. Examine ductwork
for leaks or obstruction if insufficient air is detected. Set
the thermostat fan mode to AUTO. The blower should
stop running.
LP/Propane Gas Conversion
WARNING:
This unit was equipped at the factory for use
with natural gas only. A special kit, supplied by
the manufacturer, is required to convert the unit
to operate on LP/propane gas. Failure to use the
proper conversion kit can cause fire, explosion,
property damage, carbon monoxide poisoning,
personal injury, or death.
Conversion of this equipment to LP/Propane gas must
be made by qualified service personnel, using approved
factory parts. LP/Propane gas conversion can be
accomplished by replacing the natural gas orifices with
the appropriate LP/Propane orifices and then adjusting the
manifold pressure as outlined on page 22.
Conversion to
LP/Propane (sea level and high altitude) is detailed in the
installation instructions provided with the conversion kit:
•
The United States LP/Propane Gas Sea Level and High
Altitude Conversion Kit (P/N 904404) is for LP/propane
conversion in the United States at altitudes between
zero and 10,000 ft. above sea level.
Please follow the
instructions provided with the kit.
•
The
Canadian LP/Propane Gas Sea Level and High
Altitude Conversion Kit (P/N 904405) kit is for LP/
propane conversions in Canada at altitudes between
zero and 4,500 ft. above sea level.
Please follow the
instructions provided with the kit.
For installations between zero and 4,999 ft. above sea
level, a #54 drill size orifice should be used. Installations
5,000 ft. above sea level require a # 55 drill size orifice.
Table 7 (page 22) lists the correct orifice size to use at
different altitudes.
After changing the orifices, it is required that you measure
the gas input rate by clocking the gas meter and using
the local gas heating value. See Verifying and Adjusting
the Firing Rate section on page 21.
