Originally Posted By: jmyers
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Thanks to everyone for their thoughts.
Here is the scenario. There was a two pole, 30 amp breaker servicing an air conditioning unit, running on #6 aluminum. After thinking about it for a while, I could not think of any codes which made it illegal or wrong.
The #6 would be rated for 40 amps which is one size larger than needed, given it was aluminum wire. The air conditioning unit was totally inaccessible so the name plate rating could not be determined. The wire run was relatively short, say 40 to 50 feet, so the only reason that I figured they could have done it would have been voltage drop. Guessing on that one!
Here is my concern. With the wire being oversized, would the breaker still trip at the rated amperage even though the wire size is increased? Meaning, if I take the #6 wire and put 35 amps through it continuously, will the 30 amp breaker still trip within the breaker amperage rating?
For all that matters, if I hook up 4/0 to the 30 amp breaker and put 35 amps through it continuously, will it still trip?
I was just thinking out loud and the brain is in overload mode today! ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)