17
Open and lock unit
disconnect switch before continuing installation. Failure to
do so could result in severe personal injury or death due to
electrical shock or contact with moving parts.
▲
!
WARNING:
Disconnect Switch
— Provide an approved weather-proof disconnect either on
the side of unit or within close proximity.
Over Current Protection
The branch circuit feeding the unit must be protected as shown
on the unit rating plate.
Power Wiring
— The power supply lines must be run in weather-tight
conduit to the disconnect, and into the bottom of the unit
control box. Provide strain relief for all conduit with suitable
connectors.
— Provide flexible conduit supports whenever vibration
transmission may cause a noise problem within the
building structure.
— Insure all connections are made tight. See Figure10.
Note:
For branch circuit wiring (main power supply to unit
disconnect), Wire size for the length of run should be deter-
mined using the circuit ampacity found on the unit nameplate.
— For more than 3 conductors in a raceway or cable, for de-
rating the ampacity of each conductor.
GROUNDING: THE UNIT MUST BE ELECTRICALLY
GROUNDED IN ACCORDANCE WITH LOCAL AND NA-
TIONAL CODES .
Note:
Unit must be grounded for igniter to operate properly.
Gas pipe to unit is not an adequate ground. Ground the unit
internally as provided. See wiring diagram for location.
Figure 10 Typical Field Wiring Diagram
Control Wiring
Note: Some models have a 24 volt transformer with an integral
circuit breaker. If the breaker trips, open unit disconnect before
attempting to reset breaker. Models with a 50VA transformer
do not have this circuit breaker.
Remove compressor access panel and control box panel to
access transformer. Reset by pressing in on the black reset
button located on the left side of the transformer.
Replace all panels before restoring power to the unit.
Important Note: The unit 24 volt transformer must not be
used to power Field Installed Accessories (FIA), except for the
ones that are factory supported.
— Low voltage control wiring must not be run in conduit with
power wiring. Route low voltage (class II) colored wire from
zone sensor terminals through 7/8 inch bushing in the unit.
See Figure 1 for control entry location. Make connections
as shown by the appropriate low voltage wiring diagrams in
Figure 11.
— Zone sensor conductors are standard thermostat wire 22 to
14 ga. The only exceptions are Tracer/Tracker installations
which utilize a serial communications link and require a
shielded twisted pair of conductors between Tracer/Tracker
and the (TCI) Communications Interface .
— Recommended wire sizes and lengths for installing the
zone sensor are provided in Table 5. The total resistance of
these low voltage wires must not exceed 2.5 ohms per
conductor. Any resistance in excess of 2.5 ohms may
cause problems with the accuracy of the zone sensor
setpoint.
