Circuit Breaker Protection (#125)

 



WATTS divided by VOLTS = AMPS     (WATTS / VOLTS = AMPS)

However, Section 422-14 of the National Electric Code reads:

“b) Storage type water heaters. All fixed storage type water heaters             having a capacity of 120 gallons or less  shall have a branch – circuit rating not less than 125 percent of the nameplate rating of the water heater.”

The chart below shows the recommended circuit breaker size for the maximum residential heater wattage.  The maximum wattage and rated voltage are shown on the water heater data plate.

Since a water heater acts as a continuous duty service appliance, (the elements usually heat for an extended period of time) the service wires get warm, increasing electrical resistance and requiring more amperage draw.  If the circuit breaker, permissible by code, is a quick acting circuit breaker it can trip regularly and cause inconvenience and aggravation.

Therefore, our installation instructions use the word RECOMMENDED rather than REQUIRED.

Recommended for Amperage

 

Max

Max Volts

Max

Max Volts

 

Watts

120V

208V

240V

Watts

208V

240V

600

10A

5A

5A

3500

25A

20A

750

10A

5A

5A

3800

25A

25A

1000

15A

10A

10A

4000

25A

25A

1250

15A

10A

10A

4500

30A

25A

1500

20A

10A

10A

5000

35A

30A

2000

25A

15A

15A

5500

35A

35A

2500

30A

15A

15A

6000

40A

35A

3000

35A

20A

20A

     

 

Consult the local electric power company to determine the correct electrical hook-up in order to meet local utility and building codes.