Instant tankless water heater

[hhsting]

I have 208V single phase 4160 kw tankless instant hot water heater. See below link. Should the breaker be sized 20A, 25A or 30A?

https://www.zoro.com/chronomite-208vac-20-amps-both-electric-tankless-water-heater-sr-20l208-htr-i/i/G3709036/?utm_source=google&utm_medium=surfaces&utm_campaign=shopping+feed&utm_content=free+google+shopping+clicks&campaignid=21413729702&productid=G3709036&v=&gad_source=1&gbraid=0AAAAADw3hZcjYUExoogG_i7kJgwjTb_kw#specifications

 

[LarryFine]

I'd say 25 or 30 amps.

 

[wwhitney]

Storage type water heaters of 120 gallons or less are considered continuous loads for the purposes of sizing the branch circuit per 422.13. But that would not apply to the water heater in the OP.

Electric pool water heaters need to have OCPD not less than 125% of the nameplate-rated load, per 680.10. So if the water heater is used for that application, 25A would be the minimum.

Otherwise, I see no reason that 20A would not be the minimum.

Cheers, Wayne

 

[hhsting]

Storage type water heaters of 120 gallons or less are considered continuous loads for the purposes of sizing the branch circuit per 422.13. But that would not apply to the water heater in the OP.

Electric pool water heaters need to have OCPD not less than 125% of the nameplate-rated load, per 680.10. So if the water heater is used for that application, 25A would be the minimum.

Otherwise, I see no reason that 20A would not be the minimum.

Cheers, Wayne

This is tankless instantaneous water heater. Where do you see storage type?

 

[hhsting]

I'd say 25 or 30 amps.

How?


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[infinity]

I have 208V single phase 4160 kw

Is that 4.160 kw? 4160000w/208v=20,000 amps

 

[retirede]

Is that 4.160 kw? 4160000w/208v=20,000 amps

What’s a couple of decimal places between friends?

 

[LarryFine]

How?

20 x 1.25. I wouldn't want a full 20a load, continuous or not, on only a 20a circuit.

Even a non-storage water heater could be on for three hours, intentional or otherwise.

 

[LarryFine]

What’s a couple of decimal places between friends?