24
Electrical
Before connecting power to the unit, read and understand the entire section of this document. As-built
wiring diagrams are furnished with each control by the factory and are attached to the module’s door.
When installed, the appliance must be electrically grounded in accordance with local codes, or in
the absence of local codes, with the National Electrical Code, ANSI/NFPA 70, and/or the Canadian
Electrical Code, CSA C22.1, if an external electrical source is utilized.
Verify the voltage and phase of
the power supply, and the wire amperage capacity is in accordance with the unit nameplate. Refer to
for wire size and amperage ratings.
•
Always disconnect power before working on or near a unit. Lock and tag the disconnect switch
and/or breaker to prevent accidental power-up
.
• The main electrical feed should be brought through one of the conduit openings located in the base of
the unit, within the perimeter of the curb.
DO NOT ROUTE WIRING WITHIN THE SUPPLY OR
RETURN DUCT.
• A dedicated branch circuit should supply the unit with short circuit protection according to the National
Electric Code.
• Make certain that the power source is compatible with the requirements of your equipment. The unit
nameplate identifies the proper phase and voltage of the equipment.
• Units shipped with an optional remote HMI panel have separate wiring requirements. It is important to
run the main electrical wires in a separate conduit from the remote control HMI wiring. The HMI wiring
is Cat-5 and must be separate from power cable. Maximum distance on any low voltage wire is 1000
feet.
• Before connecting the unit to the building power source, verify power line wiring is de-energized.
• Secure the power cables to prevent contact with sharp objects.
• Do not kink power cable and never allow the cable to come in contact with oil, grease, hot surfaces, or
chemicals.
• Before powering up the unit, check fan wheel for free rotation and make sure that the interior of the
heater is free of loose debris or shipping materials.
• If any of the original wire supplied with the appliance needs to be replaced, it must be replaced with
wiring material having a temperature rating of at least 149°F and type TW wire or equivalent.
•
Seal ALL base penetrations with an appropriate filler (caulk or all-purpose putty) to prevent
water from entering the space. Refer to
.
WARNING: Low Voltage Wiring Should Never Route Together With High Voltage Wiring.
WARNING!!
Disconnect power before installing or servicing control. High voltage electrical input is needed
for this equipment. A qualified electrician should perform this work.
Table 10 - Copper Wire Ampacity
Wire Size
Maximum Amps
Wire Size
Maximum Amps
14 AWG
15
1/0 AWG
150
12 AWG
20
2/0 AWG
175
10 AWG
30
3/0 AWG
200
8 AWG
50
4/0 AWG
230
6 AWG
65
250 MCM
255
4 AWG
85
300 MCM
285
3 AWG
100
350 MCM
310
2 AWG
115
400 MCM
335
1 AWG
130
500 MCM
380
600 MCM
420
