Service Procedure Vi: Contactor Testing - Bradford White ElectriFLEX HD CEHD 50 Service Manual

Contactor Operating Coils
This procedure assumes control circuit is operating correctly.
Providing the water temperature in tank is within the operating
range of the thermostat, checking contactor operation can be
as simple as rotating the thermostat dial and listening to the
contactor(s) to see if they respond to a call for heat.
1. Turn Power "ON" and rotate thermostat dial to the maximum
setting, with water temperature in tank below the thermostat
setting, the contactor(s) will close. With the contacts closed,
check for line voltage across operating coil terminals (see
illustration 10).
A) Line voltage IS present, okay, go to step 2.
B) Line voltage NOT present, verify control circuit
operation.
2. Check for rated voltage across lower terminals of contactor(s)
(see illustration 11).
A) Rated voltage IS present, okay, go to step 3.
B) Rated voltage NOT present, replace contactor.
3. Rotate thermostat dial to the minimum setting. With water
temperature in tank above thermostat setting, the contactor(s)
will open. With the contacts open, voltage should not be
present at lower terminals of contactor(s).
4. Check for line voltage across operating coil terminals (see
illustration 10).
A) Line voltage IS present, verify control circuit
operation.
B) Line voltage NOT present, okay go to step 5.
5. Check for rated voltage across lower terminals of contactor(s)
(see illustration 11).
A) Rated voltage IS present, replace contactor.
B) Rated voltage NOT present, contactor is okay.
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Service Procedure VI:
Contactor Testing
18
WARNING
High voltage exposure. Use caution when making
voltage checks to avoid hazard to life or property.