Instantaneous water heaters for 240 and 208V Breaker Size.

[Cartoon1]

Hi All. How do you typically size circuit breaker size for instantaneous water heaters? for 240V and 208V. I'm looking at the HA036240. As you can see in the attached It shows (4x38) for 240V and (4x32) for 208. My system is 208V, taking into consideration 32 X 125% = i end up with a 40A Breaker for each circuit. Now from what i see regarding these water heaters (different manufacturers) Is typically they show 240V and a recommended 40A breakers for a 36KW, they never show 208V in many instances. This particular one shows amperage: So 40A breaker for 208 or should it be 35A for 208?

Thank you,

 

[infinity]

My system is 208V, taking into consideration 32 X 125% = i end up with a 40A Breaker

Why the 125%? This type of water heater would likely not be considered a continuous load and is not a storage type heater. IMO you could use either a 35 or 40 amp circuit.

 

[Cartoon1]

Why the 125%? This type of water heater would likely not be considered a continuous load and is not a storage type heater. IMO you could use either a 35 or 40 amp circuit.

You are right, even at 100% though i still like to use the 40A breaker. I just want to make sure if i use 40A at 208V that I'm not making a code violation somewhere.

 

[LarryFine]

40a looks right to me.

 

[infinity]

I agree with Larry unless the manufacturer instructions say otherwise a 40 amp circuit is code compliant.