Water Heater Circuit Breaker Size

[Mike Lamb]

What would be an appropriate sized breaker for this WH?

[Mike Lamb]

I am replacing a 2 pole 30 amp breaker - if that is the right size - for this tank. Murray panels and breakers are discontinued. Need help as to what specific breaker should I get? This is beyond my expertise.

[Marc]

30 Amp.

[Bill Kibbel]

Quote

What would be an appropriate sized breaker for this WH?

23.4 amps. You won't find one, so

25 Amps.  Might not find one, so

30 amps. You'll find one.

[Jim Katen]

Like Bill said, a 25- or 30-amp breaker is fine - IF you have 240-volt power. 

I'd use a Siemens brand breaker. They've owned the Murray line for quite a while. 

[Mike Lamb]

Thanks.

[mtwitty]

Both 25 and 30 amp are compliant if the supply is 240 volts. If the supply is 208 volts, only a 25 amp breaker is allowed.

[Marc]

Why? Assuming the OCP device is sized to protect the circuit conductors.

[mtwitty]

1 hour ago, Marc said:

Why? Assuming the OCP device is sized to protect the circuit conductors.

The NEC states that the OCD is "not to exceed" 150% of the rated current. 422.11(E)(3) At 208 volts, that current would be 24.4 amps. The next standard size breaker is 25, which is the only one allowed in this scenario.

[Marc]

After all these years..I had no idea.

[mic20]

I installed the same WH I bought from LINK DELETED. They helped me install it and the size of the circuit breaker is 30 amp.

Edited August 2, 2022 by Bill Kibbel

[Bill Kibbel]

5 hours ago, mic20 said:

I installed the same WH I bought from LINK DELETED. They helped me install it and the size of the circuit breaker is 30 amp.

What's the voltage there in Romania?