A.O. Smith 120 trough 500 - Manual (Page 29)

BTR TANK TYPE HEATERS
SERVICE HANDBOOK
A.O. Smith Water Products Service Handbook
Irving, Texas ©2000 Training Department
28
HARNESS CHART
Heater Harness Function Damper Harness
Black 24V Hot 1-Brown
Yellow 24V from Therm 2-Orange
Red 24V from damper 3-Yellow
White 24V common 4-Black
Series 110 and 111 heaters and converted model BTR(C) and BTC heaters with Effikal
Dampers.
NORMAL OPERATION
Condition:
• Heater on standby
• Damper closed
• High Limit closed
STEP A
TEST FOR 24VAC BETWEEN BLACK (COMMON)
AND BROWN
STEP A. TEST FOR 24VAC BETWEEN BLACK (COMMON) AND BROWN
IF THEN
24VAC is present Continue to Step B.
24VAC is not present See Troubleshooting Step A1
Wires are from left to right:
Black i Yellow i Brown i White