10
•
Refer to the NEC (USA) or CSA (Canada) for wire siz-
ing. The unit MCA for the air handler and the optional
electric heat kit can be found on the unit Series and
Rating Plate.
•
Wire must be sized to allow no more than a 2% volt-
age drop from the building breaker/fuse panel to
the unit.
•
Wires with different insulation temperature rating have
varying ampacities - be sure to check the temperature
rating used.
Refer to the latest edition of the National Electric Code
or in Canada the Canadian Electric Code when deter-
mining the correct wire size.
12.3 Maximum Overcurrent Protection (MOP)
Every installation must include an NEC (USA) or CEC
(Canada) approved overcurrent protection device. Also,
check with local or state codes for any special regional
requirements.
Protection can be in the form of fusing or HACR style
circuit breakers. The Series and Rating Plate provides
the maximum overcurrent device permissible.
NOTE: Fuses or circuit breakers are to be sized larger
than the equipment MCA but not to exceed the MOP.
12.4 Electrical Connections – Supply Voltage
IMPORTANT NOTE: USE COPPER CONDUCTORS
ONLY.
Knockouts are provided on the air handler top panel
and sides of the cabinet to allow for the entry of the
supply voltage conductors, as shown in Figure 13. If
the knockouts on the cabinet sides are used for electri-
cal conduit, an adapter ring must be used in order to
meet UL1995 safety requirements. An NEC or CEC
approved strain relief is to be used at this entry point.
Some codes/municipalities require the supply wire to
be enclosed in conduit. Consult your local codes.
Side of
Cabinet
Top of
Cabinet
KNOCK-OUT FOR ELECTRICAL CONNECTIONS
Figure 13
12.4.1 Air Handler Only (Non-Heat Kit Models)
The building supply connects to the stripped black and
red wires contained in the air handler electrical com-
partment cavity. A ground screw is also contained in
this area. Attach the Supply wires to the air handler
conductors as shown in the unit wiring diagram using
appropriately sized solderless connectors or other NEC
or CEC approved means.
12.4.2 Air Handler - Non-Circuit Breaker Heat Kits
A terminal block is provided with the HKS kit to attach
the power supply and air handler connections. Follow
the HKS Installation Manual and wiring diagram for com-
plete wiring details.
12.4.3 Air Handler With Circuit Breaker Heat Kit
The air handler has a plastic cover on the upper ac-
cess panel that will require either one or both sections
to be removed to allow the heat kit circuit breaker(s) to
be installed. The circuit breakers have lugs for power
supply connection. See the HKS Installation Instructions
for further details.
12.5 Low Voltage Connections
Several combinations of low voltage schemes are pos-
sible, depending on the presence of a heat kit and
whether the heat kit is single-stage or multi-stage,
whether the outdoor section is an air conditioner or heat
pump, and whether the system is setup with a commu-
nicating or traditional thermostat. The 24V-control volt-
age connects the air handler to the room thermostat
and condenser. Low voltage wiring must be copper
conductors. A minimum of 18AWG must be used for
installations up to 50’ and 16AWG for installations over
50’. Low voltage wiring must be connected through the
top of the cabinet or either side. See the “Thermostat
Wiring” section of this manual for typical low voltage
wiring connections.
13
Achieving 2% Low Leakage Rate
Ensure all the gaskets remain intact on all surfaces as shipped
with the unit. These surfaces are areas between the upper
tie plate and coil access panel, blower access and coil ac-
cess panels, and between the coil access and filter access
panels. Ensure upon installation, that the plastic breaker cover
is sitting flush on the blower access panel and all access
panels are flush with each other and the cabinet. With these
requirements satisfied, the unit achieves less than 2% air-
flow leakage when tested in accordance with ASHRAE Stan-
dard 193.
