Wiring a 220 VAC tankless water heater

[kabel]

The heater has three wires to connect. The maximum current draw is 54 Amps. I am connecting to a double pole 60 amp circuit breaker. The wires are #6, black and white which I intend to connect to each side of the breaker. The third wire is bare copper approximately 16 gauge. My question is: does this bare wire connect to the residential ground bar with all the other bare grounds, or does it connect to the neutral bar ( white wires in 110 volt application).

[SSN596]

A bare wire can never be used as a neutral wire. It must be a grounding wire. A pure 240volt resistive heat load like an oven or water heater does not use or need a neutral connection. If the appliance has some 120 volt loads, like control circuits or small motors, then it should have a neutral connection as well. The installation instructions for your WH should be clear about how to connect it.

[lonestarheir]

Are you sure that you have a large enough breaker? As stated, your bare wire should go to the grounding bar. Check the manufacture's specs to make sure wire is large enough and right breaker size

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Brandon
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[kabel]

Thankyou for your help. There were no installation instructions with the heater so I used common sense and wired it as described with the bare ground connectd to the residential ground bar. From first use it lasted about ten minutes and had to be sent back at some expense, hence my caution with the second installation. Incidentally, a continuity test of the bare ground to the metal case of the heater yielded a no connection result.

[HayZee518]

The bare ground is indeed an equipment ground. It should be connected to the metal parts of the unit. #6 is correct for a feeder size #6 is good for 65 amps. Check out that bare 16.