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507919-01
Issue 1946
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
current 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 handler
for low-voltage control power (24VAC - 40 VA minimum).
Electric Shock Hazard. Can cause injury or
death. Unit must be properly 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.
WARNING
Fire Hazard. Use of aluminum wire with this product
may result in a fire, causing property damage, severe
injury or death. Use copper wire only with this product.
WARNING
Failure to use properly sized wiring and circuit breaker
may result in property damage. Size wiring and circuit
breaker(s) per Product Specifications and unit rating
plate.
WARNING
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.
WARNING
Refer to the unit nameplate for minimum circuit ampacity,
and maximum fuse or circuit breaker (HACR per NEC).
Install power wiring and properly sized disconnect switch.
NOTE - Units are approved for use only with copper
conductors. Ground unit at disconnect switch or
connect to an earth ground.
SIZE CIRCUIT AND INSTALL SERVICE
DISCONNECT SWITCH
NOTE - 24VAC, Class II circuit connections are made
in the control panel.
Install room thermostat (ordered separately) on an inside
wall approximately in the center of the conditioned area
and 5 feet (1.5m) from the floor. It should not be installed
on an outside wall or where it can be affected by sunlight
or drafts.
THERMOSTAT
5 FEET
(1.5M)
INSTALL THERMOSTAT
SERVICE
DISCONNECT
SWITCH
MAIN FUSE BOX/
BREAKER PANEL
Figure 4.
