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XP21 SERIES
STEP 2 -- ELECTRICAL -- Circuit Sizing and Wire Routing
In the U.S.A., wiring must conform with current local codes
and the current National Electric Code (NEC). In Canada,
wiring must conform with current local codes and the cur
rent Canadian Electrical Code (CEC).
Refer to the furnace or air handler installation instructions
for additional wiring application diagrams and refer to unit
nameplate for minimum circuit ampacity and maximum
overcurrent protection size.
24VAC TRANSFORMER
Use the transformer provided with the furnace or air han
dler for low‐voltage control power (24VAC - 40 VA mini
mum)
WARNING
Electric Shock Hazard. Can cause injury
or death. Unit must be grounded in
accordance with national and local
codes.
Line voltage is present at all components
when unit is not in operation on units with
single‐pole contactors. Disconnect all
remote electric power supplies before
opening access panel. Unit may have
multiple power supplies.
IMPORTANT !
If unit is equipped with a crankcase heater, it should
be energized 24 hours before unit start-up to pre
vent compressor damage as a result of slugging.
CAUTION
ELECTROSTATIC
DISCHARGE
(ESD)
Precautions and
Procedures
Electrostatic discharge can affect
electronic components. Take care
during unit installation and service to
protect the unit's electronic controls.
Precautions will help to avoid control
exposure to electrostatic discharge by
putting the unit, the control and the
technician at the same electrostatic
potential. Touch hand and all tools on an
unpainted unit surface before
performing any service procedure to
neutralize electrostatic charge.
1.
Size Circuit and Install Disconnect
: Refer to the unit
nameplate for minimum circuit ampacity, and maxi
mum fuse or circuit breaker size (HACR per NEC).
Install power wiring and properly sized disconnect
switch
.
NOTE -
Units are approved for use only with copper con
ductors. Ground unit at disconnect switch or connect to an
earth ground.
2.
Install Thermostat
: Install room thermostat (ordered
separately) on an inside wall in the center of the condi
tioned area and 5 feet (1.5m) from the floor. The ther
mostat should not be installed on an outside wall or
where it can be affected by sunlight or drafts
.
NOTE -
24VAC, Class II circuit connections are made in
the control box.
