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Kevin, Licensed Electrical Contractor
Category: Electrical
Satisfied Customers: 3587
Experience:  30 years Licensed Electrical Contractor in Illinois, Adjunct College Electrical Instructor, Former Electrical Inspector, Diploma: Digital Electronics, FCC Technician License
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can a low amp 4w 220V wall heater be put in line with a 40A

This answer was rated:

can a low amp 4w 220V wall heater be put in line with a 40A 220v Breaker name is XXXXX XXXXX I will be happy to assist you with your electrical question. My goal is to exceed your expectations on Just Answer!


1) What is currently being powered by the 40 amp double pole breaker? Is the 40 amp breaker being used?


2) Does 4W mean 4 wires or 4 watts? Is that a typo? Doubt that a 220 volt wall heater is 4 watts? Please confirm.

Customer: replied 3 years ago.

(1) not being used


(2) The wall heater is 220V 2.15 amps 475 WATTS

Envi wall heater

Customer: replied 3 years ago.

Are you still there!

Thanks for the replies Paul


1) No, you will need a smaller breaker, ie....a 15 amp double pole breaker to serve the small heater in question.


2) If the heater is protected by using the existing 40 amp breaker, that is a violation of the National Electrical Code, since the breaker is sized too large. That is called "over-fusing". Your connected load is only 2.15 amps, therefore the smallest breaker would be a 15 amp.




Hope this helps.........If you have any additional questions, let me know and I'll be glad to answer them for you.


Otherwise, don't forget to rate me before you log Off.


The next time you have an electrical question, you can also request for me at:


Kevin and 3 other Electrical Specialists are ready to help you
Customer: replied 3 years ago.

So if I have 2 heaters the same will the 15 amp breaker work

1) Yes, if both heaters are the same wattage and both 240 volts, your connected load will be 2 x 475 watts = 950 watts total.


Apply Watts Law where P = Watts, I = Current and E = Volts


P = I x E


Therefore, 950 W = I x 240


I = 950/240 = 3.95 amps.


2) The two heaters will be connected in parallel and served by a 15 amp double pole breaker, 240 volts.

Yes, both will work on the same 15 amp branch circuit

Thank you for the good service rating Paul..... much appreciated!


If you have any other questions, just let me know.


Take care and have a great evening..........Thanks............Kevin!