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Steve G.
Steve G., Electrical Engineer
Category: Electrical
Satisfied Customers: 17987
Experience:  Spent 20 years as an Electrical Engineer, designing electrical plans and specifications.
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I just had our breaker panel replaced (a 200 amp Federal Panel

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I just had our breaker panel replaced (a 200 amp Federal Panel was replaced with a 200 amp 40 slot , Square D panel), and i had an aux panel installed with a 220 volt temporary generator connection receptacle for emergency power. The aux panel has 8 breaker slots for the circuits we selected to be in service during emergency power. The 8 circuits were originally on 15 amp breakers in the main panel. When they were moved to and set up in the aux panel, they were connected to 20 amp breakers. These 8 circuits are always powered up, whether it is from line power or emergency generator power depending on the position of the two switches for the main power to the aux panel. Upon my questioning, the electrician said it would be OK, because the design of the circuit, and components in it allows for a certain percentage "safety factor" above the rating of the wiring in the circuit.
Do you agree? Or do I have a fire hazard here. I'm wanting to change the 20 amp breakers in the aux panel back to 15 amp if I can. The small aux panel is a GE panel.

Hello there and welcome to Just Answer. My name is XXXXX XXXXX I will be assisting you today. I am an engineer with over 30 years of electrical and electronic training, repair and installation experience. I will try and answer your question accurately and precisely so that we can get you on your way.

Now..these 15A circuits, are they for general lighting and power? What gauge is the wiring in these circuits?

If you can let me know that we can continue.

Customer: replied 4 years ago.

The circuits are general lighting, including 120 watt recessed lighting, master bathroom where hair dryer would be used, office with computer, printer etc, but no really unusually large loads except weekly use of a vacuum cleaner with a 10 amp motor. I do not know the gauge of the wiring, but the electrician described it as that normally used for a 15 amp circuit in house wiring.

Customer: replied 4 years ago.

Did you receive my response Steve?

Customer: replied 4 years ago.

I just did some looking & I believe the wiring on the 15 amp circuits is 14 gauge.

If it is 14 AWG wiring - that will be written on the sheathing, then you need 15A breakers.

If it is 12 AWG, then 20A is fine however, your receptacles should also be 20A and I bet you they are 15A.

I think the safest thing would be to swap out those breakers to 15A. A single pole 15A breaker is between $10 and $15 so the expense is not that bad. Under $100 for your peace of mind.

I'll be here if you need further help with this issue. Please let me know.

Customer: replied 4 years ago.

The 20 amp breakers in question are in the GE aux panel. Are the 15 and 20 amp breaker normally interchangeable (physically) in the panels?

GE breakers and Square D breakers are not normally interchangeable.

Sorry :(

I'll be here if you need further help with this issue. Please let me know.

Customer: replied 4 years ago.

I was referring to 20 amp and 15 amp GE breakers being interchangeable, if that is what was put into the GE aux panel

Oh yes. Absolutely. That will work. I am sorry for the misunderstanding.

If you look inside the breaker box, it should tell you what type of breakers to use. They are very likely GE THQ or THQB type. That will be molded into the breaker also or written on a label on each breaker.

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Customer: replied 4 years ago.

Thanks Steve. That should take care of me. I will have the electrician come back and change out the eight, 20 amp for 15 amp breakers as soon as I can get him here. I am a retired engineer (not electrical), but have no experience with house wiring. Thanks for your help.