UHA LOW PROFILE UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL
9.5 Internal Wiring Diagram
AXIAL FAN | AXIAL FAN (UHA 300, | |
350, 400) ONLY) | ||
|
Black
| White |
| Green |
| Black |
FLUE |
|
BLOWER |
|
| White |
| Green |
PRESSURE | Blue |
| |
SWITCH | Blue |
Green |
|
| L2 | L1 |
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| |
White |
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| White |
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| |
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| |
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| White |
| Black | Black |
| |
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| |||
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| Green |
| Green |
| ||
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| GAS VALVE | |||
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| 3 | 1 | Black | |
TRANSFORMER |
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| 4 | 5 |
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| Blue |
| Yellow |
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| |
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| Yellow |
| ||
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| Brown | ||
VAC24 HOT | GROUND |
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| |
3 | 2 | 1 |
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| 6 | 5 | 4 |
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LIMIT | Orange |
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SWITCH |
|
| Orange |
(UHA | Orange |
| |
|
| ||
300,350, |
| Flame | |
|
| ||
400 ONLY) |
|
| |
MANUAL RESET LIMIT SWITCH | LIMIT | ||
(UHA 30 - 125 ONLY) | SWITCH |
| |
SENSE |
| Black |
|
Orange
IGNITION MODULE
R
G
W
C
|
|
| R | = 24 VAC TO THERMOSTAT (RED) |
|
|
| G | = MANUAL FAN INPUT FROM THERMOSTAT (GREEN) |
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|
| W | = HEAT DEMAND INPUT FROM THERMOSTAT (WHITE) |
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| C | = COMMON SIDE OF TRANSFORMER |
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| Black |
| THERMOSTAT INPUT: |
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| FIELD SUPPLIED |
ELECTRODE
Black 
Black
Black
ACC
L1 
CMB
Blower
Black |
IMPORTANT:
For field wiring into service junction box, or if any of the original wire supplied with the heater
must be replaced, it must be replaced with wiring material having a temperature rating of at least 105° C (221° F) and 600 volts. For supply connections, use No. 14 AWG or larger wires.
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