16
START UP & ADJUSTMENTS
Pre-Start Check List
√
Verify the unit is level and allows condensate to drain.
√
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 in the low voltage area of the control box.
√
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 or 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.
System Cooling
1. Set the thermostat’s system mode to COOL and the fan
mode to AUTO. Gradually lower the thermostat temperature
setpoint below room temperature and verify the compressor,
fan and indoor blower energize.
2. Feel the air being circulated by the indoor blower and verify
that it is cooler than ambient temperature. Listen for any
unusual noises. If unusual sounds occur, determine the
source of the noise and correct as necessary.
3. Allow the cooling system to operate for several minutes and
then set the temperature selector above room temperature.
Verify the fan and compressor cycle off with the thermostat.
NOTE:
The blower will also stop after an 85 - 90 second
delay.
System Heating
1. Set the thermostat to the lowest setting.
2. Follow the procedures given on the operating instruction
label, this manual or attached inside the louvered control
access panel.
3. Set the thermostat above room temperature and verify the
Operating Sequence. See
4. Verify that the compressor and outdoor fan motor are not
energized.
5. After the unit has run for approximately five minutes, set the
thermostat below room temperature and verify the shutdown
sequence; steps 10 -12 in the Operating Sequence section
).
Verifying & Adjusting Temperature Rise
Verify the temperature rise through the unit is within the range
specified on the unit data label. Temperature rises outside
the specified range could result in premature heat exchanger
failure.
1. Place thermometers in the return and supply air stream as
close to the unit as possible. The thermometer on the supply
air side must be shielded against direct radiation from the
heat exchanger to avoid false readings.
2. Adjust all registers and duct dampers to the desired
position. Run the unit for 10 to 15 minutes before taking any
temperature readings. The temperature rise is the difference
between the supply and return air temperatures.
NOTE:
For typical duct systems, the temperature rise will fall
within the range specified on the data label (with the blower
speed at the factory recommended setting) shown in
. If the measured temperature rise falls outside
the specified range, it may be necessary to change the blower
speed. Lowering the blower speed increases the temperature
rise and a higher speed decreases the temperature rise.
The unit is equipped with a variable speed motor. Speed
selection is made by moving the leads on the blower motor
terminal block. The speed taps for adjusting the motor speed
are shown in the unit wiring diagram or
and
. Refer to the Blower Speed Section
(
) for additional information.
Ground
Joint
Union
Dripleg
Shut-Off Valve
with 1/8 NPT
plugged tap
Burner
Assembly
Manifold
Some utilities
require Shut-Off
Valve to be
4 to 5 feet
above floor
Automatic Gas Valve
(with manual shut-off)
Figure 8. Typical Gas Hookup - Right Side Entry
