Thomas & Betts UDAP - Manual (Page 16)

Form RZ-NA I-UDA, P/N 195673 Rev 5, Page 16
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.
14. Electrical
Supply and
Connections
FIGURE 12 - Supply
Wiring Connections at
the Circuit Board (DSI
Integrated Control
Module) Supply Wiring
Connections
NOTE: Circuit
board is polarity
sensitive; “hot” wire
must be connected
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.
CAUTION: Route wires
so that they do not
contact the flue wrapper
or venter housing.
15. Thermostat
and
Connections
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.
13. Burner
This heater has a one-piece
T CORE
2
® 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.
24V Control Wiring
Connections
Spark
Transformer
Contr
ol
Plug
Fuse
Thermostat
Connections
Fan/Blower
Off
Delay
Status
Lights
x