SBD TANK TYPE HEATERS
SERVICE HANDBOOK
Technical Training Department
Ashland City, TN ©2003
26
HARNESS CHART
Heater Harness
Function
Damper Harness
Black
24V Hot
1-Brown
Yellow
24V from Thermostat
2-Orange
Red
24V from damper
3-Yellow
White 24V
common
4-Black
NORMAL OPERATION
Condition:
•
Heater on standby
•
Damper closed
•
High Limit closed
STEP 8
TEST FOR 24VAC BETWEEN BLACK (COMMON)
AND BROWN
STEP 8. TEST FOR 24VAC BETWEEN BLACK (COMMON) AND BROWN
IF THEN
24VAC is present
Continue to Step 8A.
24VAC is not present
See Troubleshooting Step 9A
Wires are from left to right:
Black
i
Yellow
i
Brown
i
Orange