Water heater overcurrent protection

[hhsting]

I have 2000 watts, 277V single phase water heater. I do not have overcurrent rating marked. Panel schedule shows 20 amps branch circuit breaker to use for the water heater with 2#12 conductors #12 ground.

However, according to NEC 2014 Article 422.13, 2000w/277v = 7.22a. 7.22ax1.25= 9.02 amps so to use next standard size branch circuit breaker which would be 15 amps.

Also, NEC 2014 Article 422.11(E)(2) says to not to exceed 20 amps breaker since appliance is rated under 13.3a.

So this can mean I am allowed per code to use either 15amps or 20amps branch circuit breaker for the water heater?

 

[infinity]

Is this a storage type heater or an instant hot/point of use type?

 

[hhsting]

The water heater in question is a storage type heater.

 

[infinity]

According to the sections you've provided IMO a 15 or 20 amp circuit would be compliant however with a load of 7.2 amps I wouldn't be surprised if the manufacturer's instructions call for a 15 amp circuit.

 

[Dennis Alwon]

I agree-- 15 or 20 amp circuit. No need for a 20 so I would use a 15 amp overcurrent protective device.