OPERATION & SERVICE
Servicing should only be performed by a Qualified Service Agent
26
Heating Element Voltage Test
This test is typically performed after an amperage test (page 25) has determined one or
more heating elements (or heating element loops) is not drawing the correct amperage.
There are five standard element/contactor wiring configurations for the water heaters
covered by this manual - see pages 18 - 22. This is due to differences in power supply
phase, type of contactor(s) installed and the type of heating elements installed. Because of
these differences there will be five different methods to measure voltage to the heating
elements.
Voltage to the heating elements is always measured at the lower (output) terminals/poles of
each contactor. The measured voltage should always match the listed voltage on the water
heater’s rating label.
Voltage Test Procedure
1
Determine power supply phase/voltage to the water heater - see the water heater’s rating label.
2
Determine if the water heater is equipped with a 3 pole or 4 pole contactor(s) - see page 35.
3
Determine if the water heater is equipped with six or three wire heating elements - see page 17.
4
Locate the heating element connection/wiring diagram that corresponds to the power supply phase, type of
contactor and type of element(s) determined in Steps 1 - 3 above. See pages 18 - 22.
5
Ensure tank temperature is less than 100°F/38°C - dump water to lower tank temperature if necessary.
6
Adjust the temperature settings to ensure a call for heat is active for all heating elements. Raise the
Operating Set Point to 140°F or higher. Set all Differentials at 2°F - see pages 61 and 62.
7
Set the AC volt meter to a range above the expected voltage (600 VAC or higher range initially).
8
Follow the instruction from the list on page 27 that corresponds with the power supply phase, type of
contactor(s) and type of heating element(s) on the water heater being serviced as determined in Steps 1 -
3 above.
Three Wire Element
Six Wire Element
3 Pole Contactor
4 Pole Contactor
Single Phase (1Ø) Power
3 Pole Contactor
4 Pole Contactor
Three Phase (3Ø) Power
Measure voltage to heating
element loops at the lower
terminals of the contactors.
Six Wire Element Flange
Three Wire Element Flange