Reznor UDBS Unit Installation Manual - Manual (Page 21)

Form I-UDB, P/N 202658 R14, Page 21
CAUTION: Route wires so that they do not contact the flue
wrapper or venter housing.
The electrical supply enters at the rear of the heater (See FIGURE 17).
Model UDBS includes a built-in disconnect switch. The switch on UDBS 30-125 has
a 20A@115V and a 10A@230V inductive rating. The switch on UDBS 150-400 has
a 30A@115V and a 15A@230V inductive rating. Model UDBS supply wiring connec-
tions are made inside the sealed electrical box. Sizes 30-125 connect to leads from the
circuit board; Sizes 150-400 connect to terminals on either the starter or contactor. To
maintain the sealing feature of the electrical box, always replace the cover plate.
Model UDBP supply wiring connections are made in the control compartment; Sizes
30-125 to leads from the circuit board and Sizes 150-400 directly to the terminals on
the starter or contactor.
The circuit board (See
FIGURE 16) is located inside on the bottom of the control com-
partment. 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.
The terminal strip for 24 volt thermostat connections is located on the outside of the
cabinet at the back of the heater (See FIGURE 17). Wires from the terminal strip are
factory wired to the circuit board.
FIGURE 16 - 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.
Spark
Transformer
Control
Plug
Fuse
Thermostat
Connections
Status
Lights
x
7.3 24V Control
Wiring
Connections
FIGURE 17 - Terminal
Strip for 24-volt wiring
is on the outside rear of
the heater.
Supply
Wiring
Entrance
R
G
W1
W2
R
G
W1
W2
Supply
Wiring
Entrance
Terminal
Strip
Terminal
Strip
Built-in
Disconnect
Switch
Rear View - Model UDBP
Rear View - Model UDBS
NOTE: The size of heater
illustrated has a vertical
terminal strip. Some sizes
have a horizontal terminal
strip.