Sub panel wire gauge question


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Old 01-29-17, 05:47 PM
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Sub panel wire gauge question

Hi everyone. Long time reader, first post...

So I have a 150 amp service panel. In that panel is a 30 amp breaker with 10 gauge wire going upstairs to a sub panel that has five 20 amp breakers that run the lights and receptacles for two small bedrooms and a hallway light. Is that a safe configuration? I don't want a fire but I also don't want to go rewiring. Thanks for your help!
 
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Old 01-29-17, 05:59 PM
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Yes, safe and normal. Safe because #10 wire is rated for 30 amps so the breaker size is correct. Normal because the total of breaker amp ratings normally exceed panel supply rating. The actual load at any time is what is important. None of the breakers are probably ever at full amp capacity and never at the same time.

If the 30 amp breakers start tripping then you might have a problem but the loads you describe shouldn't be a problem. Remember too depending on how the loads or balanced you have up to 60 amps at120 volts. That is 30 amps on each of the 240v legs.
 

Last edited by ray2047; 01-29-17 at 07:22 PM.
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Old 01-29-17, 06:20 PM
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Awesome! Thanks Ray. I was worried but then again the panel says it was installed in 96 so if its been good for that long it's probably fine
 
 

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