18
18-BB42D1-1A-EN
Unit Startup
Pre-Start Quick Checklist
☐
Is the unit properly located and level with the
proper clearances? See,
.
☐
Is the duct work correctly sized, run, taped,
insulated, and weatherproofed with proper unit
arrangement as shown in the ductwork installation
section?
☐
Is the condensate line properly sized, run, trapped,
and pitched and shown in the Condensate Drain
Piping section?
☐
Is the filter of the correct size and quantity? Is it
clean and in place? See Air Filter Installation
section.
☐
Is the wiring properly sized and run according to the
unit wiring diagram?
☐
Are all the wiring connections, including those in
the unit tight?
☐
Has the unit been properly grounded and fused
with the recommended fuse size?
☐
Is the thermostat well located, level, and correctly
wired? See Electrical Wiring section
☐
Have the air conditioning systems been checked at
the service ports for charge and leak tested if
necessary?
☐
Do the condenser fan and indoor blower turn free
without rubbing and are they tight on the shafts?
☐
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?
Starting the Unit in Cooling
Mode
N
No
otte
e:: See the section on Sequence of Operation for a
description of the cooling operating sequence.
To start the unit in the cooling mode, set the comfort
control to C
CO
OO
OLL and to a setting below room
temperature. The condenser fan motor, compressor
and evaporator fan motor will operate automatically.
Continuous fan mode during Cooling operation may
not be appropriate in humid climates. If the indoor air
exceeds 60% relative humidity or simply feels
uncomfortably humid, it is recommended that the fan
only be used in the A
AU
UTTO
O mode.
O
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After the unit has operated in the cooling mode for a
short period of time, install pressure gauges on the
gauge ports of the discharge and suction line valves
(behind the Compressor access panel). Check the
suction and discharge pressures and compare them to
the normal operating pressures provided in the unit’s
SERVICE FACTS.
N
No
otte
e:: Do not use the PRESSURE CURVES from the
unit's SERVICE FACTS to determine the unit
refrigerant charge. The correct charge is shown
on the unit nameplate. To charge the system
accurately, weigh in the charge according to the
unit nameplate and check subcooling against the
Subcooling Charging Table in the SERVICE
FACTS.
V
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With the compressor operating, check the line voltage
at the unit (contactor is located behind the Control
access panel). The voltage should be within the range
shown on the unit nameplate. If low voltage is
encountered, check the size and length of the supply
line from the main disconnect to the unit. The line may
be undersized for the length of the run.
C
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Shhuutt D
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Set the comfort control to O
OFFFF or to a setting above
room temperature.
IIm
mp
po
orrtta
an
ntt:: De-energize the main power disconnect
ONLY when servicing the unit. Power may
be required to keep the heat pump
compressor warm and to boil off
refrigerant in the compressor.
Starting the Unit in Heating
Mode
N
No
otte
e:: See the section on Sequence of Operation for a
description of the heat pump heating operating
sequence.
Check that all grills and registers are open and all unit
access panels are closed before start-up.
Set the comfort control above room temperature until
achieving a first stage call for heat and set the fan to
A
AU
UTTO
O or O
ON
N.
H
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Set the comfort control to O
OFFFF or at a setting below
room temperature.
