OPERATION & SERVICE
Checking Three Phase (3Ø) Power
A three phase power supply consists of three wires connected to the L1, L2 and L3 terminals of the Power Distribution Block. All three wires are “hot” with voltage present.
Voltage Between Terminals: Set the volt meter to an AC voltage range above the expected voltage (600 VAC or higher range initially). Checking three phase (3Ø) power requires that three voltage readings be taken between all possible parings of the terminals on the Power Distribution Block. Carefully touch the two test probes between:
1L1 and L2 terminals of the water heater’s Power Distribution Block
2L2 and L3 terminals of the water heater’s Power Distribution Block
3L1 and L3 terminals of the water heater’s Power Distribution Block
All three voltage readings should match the voltage listed on the water heater’s rating label by ± 5%.
Voltage to Ground: Check between each of the three terminals (L1, L2 and L3) of the Power Distribution Block and the ground wire connection inside the water heater’s control panel. On some 208 volt power supplies each reading will be approximately 120 volts to ground. Some 208 volt models will have a “stinger leg” with one of the three readings to ground measuring 208 volts - 208 volt stinger legs should be connected to L2. On 240 volt power supplies each reading should be approximately 120 volts to ground. On 480 power supplies each reading to ground should be approximately 277 volts.
Service Warning: Zero or low voltage readings between internal wiring and/or Power Distribution Block terminals and ground can be due to an inadequate earth ground. TREAT ALL WIRES AS BEING HOT until it has been determined there is no voltage present.
If the voltage readings taken between L1, L2 and L3 are more than ± 5% of the listed voltage on the water heater’s rating label or if the readings to ground were far less (at or near zero volts) than expected: check the fuses and the breaker and/or disconnect switch supplying power to the water heater. Contact a Qualified/Licensed electrician to restore power. If the voltage readings taken are a standard voltage (277/208/240/480) but do not match the listed voltage on the water heater’s rating label secure power to the water heater. DO NOT place it back in service. Contact the distributor and/or manufacturer to determine if the water heater can be field converted and/or replaced to match the power supply at the location.
L1 L2 L3
Power Distribution Block
(see Figures 1 & 2 on pages 8 and 9)
208/240/480 Volt 3Ø Power
Servicing should only be performed by a Qualified Service Agent
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