Rev. B 4-16-02
3
P/N 472091
C. WIRING
1. Look at the existing wiring diagram on the left door and find out what model of the NT heater you have from top
of wiring diagram.
NOTE
First check the three terminals on your blower. If there are male terminals, please cut them and replace with
female terminals, (provided in the kit).
•
If you see “MiniMax NT 400 Low NOx” that means your heater is Single Voltage
Dual Speed
(SVDS):
Replace the new wiring diagram for SVDS. The label is provided in
the kit, (P/N 472084).
• Please see
Figure 2 for SVDS
and follow the instructions below exactly.
a. Reconnect existing wire P7 to J7, P9 to J9, and P10 to J10 respectively on the 6800 control board.
b. Reconnect the existing white wire from Low Gas Pressure Switch to “TH” on the Ignition Module.
c. Reconnect the existing 5-pin Mate-N-Lok Plug (with gray, black, white and blue wires) to Ignition Module.
The male terminals of gray and blue wire connect to Hot Surface Igniter (HIS #1).
d. Connect
new wire #P11
to J11. Then, connect the common female terminal, orange wire, to “IND” on the
Ignition Module; next, connect the common female terminal, (red/blue) wire, to “VAL” on the Ignition Module.
e. Connect existing wire P4 to J4 but using “splice” to connect
new wire #1
(orange). The female terminal connect
to “24VAC” on Ignition Module.
f. Connect
new wire #2
(white).
The common male terminal connect to white wire of P11; the 1
st
female terminal
connect to “GND” on the Ignition Module; the 2
nd
female terminal connect to “RET” on the Fan Board.
g. Connect
new wire #3
(white).
The common male terminal connect to white wire of the Blower; the female
terminal connect to F1 terminal of Ignition Module; the other female terminal connect to Hot Surface Igniter (HIS #2).
h. Connect
new wire #4
(orange).
The common female terminal connect to “24 VAC” on the Fan Board; the
female terminal connect to “PC” on the Fan Board; the male terminal connect to orange wire of P11.
i.
Connect the
new wires #5
(white), from F2 of Ignition Module to Terminal Block #4.
j.
Install the In-Line Fuse (provided in the kit) between the Hot Surface Ignitor (HSI #2) and the blower, see Wiring
Diagram (Figure 2).
•
If you see “MiniMax NT 250 Low NOx” that means your heater is Single Voltage
Single Speed
(SVSS):
Replace the new wiring diagram for SVSS. The label is provided in
the kit, (P/N 472088).
• Please see
Figure 3 for SVSS
and follow the instructions below exactly.
a. Reconnect existing wire P7 to J7, P9 to J9, and P10 to J10 respectively on the 6800 control board.
b. Reconnect the existing white wire from Low Gas Pressure Switch to “TH” on the Ignition Module.
c
Reconnect the existing 5-pin Mate-N-Lok Plug (with gray, black, white and blue wires) to Ignition Module.
The male terminals of gray and blue wire connect to Hot Surface Igniter.
d. Connect
new wire #P11
to J11. Then, connect the common female terminal (orange) wire to the Air Pressure
Switch; then connect the female terminal (orange) wire to the “IND” on the Ignition Module; next, connect the
common female terminal (red/blue) wire to “VAL” on the Ignition Module; last, connect the female terminal
(white) wire to “GND” on the Ignition Module.
e. Connect existing wire P4 to J4 but using “splice” to connect
new wire #1
(orange). The female terminal connect
to “24VAC” on Ignition Module.
f. Connect the
new wires #5
(white) from F2 of Ignition Module to Terminal Block #4.
g. Connect the
new wire #6
(white) from F1 of Ignition Module to the white wire of the Blower.
