Thomas & Betts UDAS, UDAP Burner 14.Electrical Supply and Connections, Thermostat and Connections

13.Burner

14.Electrical Supply and Connections

CAUTION: Route wires so that they do not contact the flue wrapper or venter housing.

CAUTION: If any of the original wire as supplied with the appliance must be replaced, it must be replaced with wiring material having a temperature rating of at least 105°C, except for limit control, flame rollout, and sensor lead wires which must be 150°C. See Hazard Levels, page 2.

FIGURE 12 - Supply

Wiring Connections at

the Circuit Board (DSI

Integrated Control

Module)

24V Control Wiring Connections

15.Thermostat and Connections

This heater has a one-piece TCORE2® burner assembly (patent pending) designed

to provide controlled flame stability without lifting or flashback with either natu- ral or propane gas.

The burner can be removed as a unit for inspection or service; see Maintenance Section for removal instructions.

All electrical wiring and connections, including electrical grounding MUST be made in accordance with the National Electric Code ANSI/NFPA No. 70 (latest edition) or, in Canada, with CSA Standard C22.1. In addition, the installer should be aware of any local ordinances or gas company requirements that might apply.

Check the rating plate on the heater for the supply voltage and current require- ments. A dedicated line voltage supply with disconnect switch should be run di- rectly from the main electrical panel to the heater. All external wiring must be within approved conduit and have a minimum temperature rise rating of 60°C. Conduit must be run so as not to interfere with the heater access panel. If the installation requires a stepdown transformer (Option CG), follow the instructions shipped with the option package for attaching the transformer to the heater.

The electrical supply enters at the rear of the heater (See FIGURE 13). Model UDAS includes a built-in disconnect switch (20A @ 115V; 10A @ 230V Rating). Model UDAS supply wiring connects to leads located inside a sealed electrical box. To maintain the sealing feature of the electrical box, always replace the cover plate. Model UDAP supply wiring connects directly to leads on the integrated circuit board.

The circuit board (See FIGURE 12) is located inside on the bottom of the control compartment. The circuit board is polarity sensitive. It is advisable to check the electrical supply to be certain that the black wire is the “hot” wire and that the white wire is the neutral wire. The supply connection made to “L1” on the circuit board must be the “hot” wire.

		x
	Spark
	Transformer	Control Plug
		Fuse
		Thermostat
		Connections
Supply Wiring
Connections
NOTE: Circuit		Fan/Blower
		Off
board is polarity
		Delay
sensitive; “hot” wire		Status
must be connected
		Lights
to Terminal L1.

For all models, the terminal strip for 24 volt thermostat connections is located on the outside of the cabinet at the back of the heater (See FIGURE 13). Wires from the terminal strip are factory wired to the circuit board.

Use either an optional thermostat available with the heater or a field-supplied 24- volt thermostat. Install according to the thermostat manufacturer's instructions, pay- ing particular attention to the requirements regarding the location of the thermo- stat.

Form RZ-NA I-UDA, P/N 195673 Rev 5, Page 16