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IMPORTANT: After completion of wiring, check all
electrical connections, including factory wiring within the
unit, and ensure all connections are tight. Replace and
secure all electrical box covers and access doors before
leaving unit or connecting power to circuit supplying unit.
After all electrical wiring is complete, SET THE ZONE
SENSOR SWITCH TO THE OFF POSITION AND THE
FAN SWITCH TO AUTO SO COMPRESSOR AND FAN
WILL NOT RUN, and apply power by closing the system
main disconnect switch. This will activate the compressor
crankcase heaters. Do not change the zone sensor
setting until power has been applied long enough to
evaporate any liquid refrigerant in the compressor. It is
recommended the crankcase heaters be energized for 8
hours prior to starting.
Pre-Start Quick Check List
[ ] Is unit properly located and level with proper clear-
ances? See Figure 2.
[ ] Is the duct work correctly sized, run, taped, insulated
and weather proofed with proper unit arrangement?
(See duct work installation)
[ ] Is the gas piping correctly sized, run, trapped and
purged of air? (See gas piping)
[ ] Is condensate line properly sized, run trapped and
pitched?
[ ] Is the filter of the correct size and number, clean and
in place?
[ ] Is the wiring properly sized and run in according to the
unit wiring diagram?
[ ] Are all wiring connections tight including those in unit
and compressor electrical boxes?
[ ] Has the unit been properly grounded and fused with
the recommended fuse size? (See wiring data)
[ ] Is the zone sensor correctly wired and in a good
location?
[ ] Have the air conditioning systems been checked at
the service ports for charge and leak tested if neces-
sary?
[ ] Does the condenser fan and indoor blower turn freely
without rubbing and are they tight on the shafts?
[ ] Is the indoor fan rotation correct?
[ ] Has the indoor blower speed been determined and
the proper speed been set? (See air flow performance
data)
[ ] Has all work been done in accordance with applicable
local and national codes?
[ ] Are all covers and access panels in place to prevent
air loss and safety hazards?
START-UP
high voltage electrical components. If operating checks
must be performed with the unit operating, it is the
technician's responsibility to recognize these hazards and
proceed safely. Failure to do so could result in severe
personal injury or death due to electrical shock or contact
with moving parts.
Power-up Initialization
The "initialization" by the Unitary Control Processor (UCP)
occurs each time the system is powered-up. The UCP performs
internal self-diagnostics checks, which include identifying the
equipment components of its system, and the configuring of
itself to that system. It also checks itself to be sure it is function-
ing correctly. On units with the optional economizer, the damper
is driven open for 15-20 seconds and then fully closed. The UCP
system indicator LED is turned to "ON" within one second of
start-up if operation is correct.
Starting the Unit in the Heating Mode
The following warning complies with State of California law, Proposition 65.
!
Exposure to fuel substances or by-products of incomplete
fuel combustion is believed by the state of California to
cause cancer, birth defects, or other product reproductive
harm.
Note: See "Sequence of operation" in the unit Service Facts for
a complete description of heating operating sequence.
1. Check to ensure all grilles and registers are open and all unit
access doors are closed before start-up.
2. Purge the gas supply line of air by opening the union ahead
of the unit. When the odor of gas is detected, re-tighten
union and wait 5 minutes before proceeding.
3. Place the zone sensor system switch in the heat position.
4. Position the heating setpoint approximately 10 degrees
above room temperature and place the fan switch in "Auto"
or "On" position.
5. Open the main gas valve(s) and turn on unit main power
supply.
Note: To bypass time delays, and verify the operation of this
unit from the roof, use the "Test mode procedure" on page 3
and 4 of this manual.
1. The combustion blower motor and ignitor should energize.
The main burners should light within one minute from the
time the combustion blower starts. Initial start may be
delayed somewhat if unit is not purged and air is trapped in
gas line.
2. If burners fail to ignite after 3 tries the ignition system will
lockout. Reset by disconnecting and re-applying unit power.
3. Unit will start in the high fire mode. After a short run cycle it
will switch to low fire.
Note: Blue smoke produced by the heat exchanger during the
initial burner firing is caused by a thin film of oil on the surface of
the heat exchanger. This oil will burn off quickly.
Check control operation and burner operating conditions through
the sight glass in burner assembly cover.
21
Bodily injury can result from
Hazardous Gasses!
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