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jackdawson1049 t1_iw71259 wrote

Reply to comment by Hattix in Running wire to power this 20x10 shed for an office. What wire do I need? by skinnywolfe

Funny, I was taught to use RMS.

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Hattix t1_iw8a6ji wrote

A breaker will trip on a peak current. It's not much of a 30A breaker if it lets 42.5A past now, is it?

However, don't just believe some random yahoo on the Internet with electrical safety, test it out in a controlled and safe setup.

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JonJackjon t1_iw8p437 wrote

> A breaker will trip on a peak current. It's not much of a 30A breaker if it lets 42.5A past now, is it?

A thermal magnetic breaker trips at different rates.

Magnetic circuit trips the breaker when a short or near short is experienced. They are rated to trip at 2 to 5 times the rated current. Whether 2, 3, 4 or 5 times depends on the type of breaker.

The thermal circuit will trip the breaker when enough heat is generated due to the current flow. Since is it heat related the current is sensed as RMS.

This is a safety and a local code issue. Please do not suggest solutions where you don't know the complete situation nor the local code requirements.

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jackdawson1049 t1_iw8pufx wrote

I was trying to give OP a quick and dirty example to get them in the ballpark. We haven't even considered voltage drop in the wire or the start up current draw. If I was installing this circuit based on the 3600 watt example I would be designing, based on experience, for a minimum 50 amp breaker.

Now I admit, I'm not an electrical engineer or even an electrician. I'm just a lowly PMEL tech who calibrates and repairs all of the test equipment.

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