Detroit Radiant Products Company UH Series - Manual (Page 22)

22
UH Series
Field Wiring Supply Voltage
Before proceeding with electrical connections, ensure that the supply voltage, frequency, phase and
current capacity meet the requirements specified on the rating plate. A dedicated line voltage supply
with properly sized wire should run directly from the main electrical panel to the heater. The power to
the unit must be protected with a circuit breaker appropriate for the load. The unit must be electrically
grounded in accordance with local codes, or in their absence, with the latest edition of the National
Electrical Code, ANSI / NFPA 70 and/or the Canadian Electrical Code CSA C22.1, latest edition.
An electrical service disconnect must be provided at the furnace location. A 2 x 4 junction box can be
mounted directly to the unit panel utilizing the provided 1/2” knock-out. If conditions do not allow for this,
locate the service disconnect not more than 5 feet away from the service access panel.
The main electrical supply enters at the rear of the heater utilizing 1/2” electrical knock-out (See Figure
3.6). When routing the electrical supply conduit to the unit, ensure that it does not interfere or obstruct
the heater’s service access panel.
Unit comes with three wire leads to connect the main power supply. Connect the hot, neutral and
ground wires as shown in the field wiring diagram, Figure 3.6. When routing wires through the knock-
out, use a UL Listed bushing or chase nipple to prevent damage to the wire insulation. When operating
this unit as a sealed combustion appliance, the cabinet opening to the junction box must be sealed air
tight using either a UL approved bushing or a non-reactive UL approved sealant to bushing.
The power supply to the heater must be within +/- 5% of the voltage rating as indicated on the rating
plate of the appliance. If input power does not meet these specifications, contact your utility company.
CAUTION
!
WARNING
!
Edges of sheet metal holes may be sharp. Use gloves as a precaution when
routing wires.
3.0 Installation • Field Wiring Supply Voltage