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Old 10-04-2008, 02:24 PM   #1
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Calculating load - 240 load question


I ran ever appliance I would possible run, and then threw in a couple extra heavy resistance appliances for good measure and put a clamp meter on my each side of my box so see what I was drawing.

I maxed out at right about 55A on each side of the box. My question is if I added a hot tub, and for the sake of conversation lets say it is on a 40A breaker and it draws the full 40A (I know it would not really max out the circuit).

Can a 40A double pole breaker draw 40A from each side of the panel or can it only draw a total of 40A (20A from each side)?

I don't have anything 240V that is hooked up that I know the draw of, so I don't have any way of testing this right now.

My thought is that it could only pull 20A per side max, so then my load would be 55A per side + 20A = 75A per side when I am maxed out. If this is correct, then I would only be within 75% of my 100A capacity even with what is really high usage for me.

Jamie

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Old 10-04-2008, 02:26 PM   #2
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Calculating load - 240 load question


If it is 40 amps @ 240v it is 40 amps PER SIDE. NOT 20 amps per side.

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Old 10-04-2008, 03:00 PM   #3
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Calculating load - 240 load question


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If it is 40 amps @ 240v it is 40 amps PER SIDE. NOT 20 amps per side.
Matter of fact Jamie per your scenario, in theory (and sometimes in practice) you can physically separate the two halves and have 2 individual single pole, 40 A breakers.
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Old 10-04-2008, 03:36 PM   #4
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Calculating load - 240 load question


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Matter of fact Jamie per your scenario, in theory (and sometimes in practice) you can physically separate the two halves and have 2 individual single pole, 40 A breakers.
Now that you say it this way it makes perfect sense to me. The setup where there are 2 single pole breakers bonded together, both switches attached to each other.

Wow a hot tub sure can draw alot of power compared to many 120 appliances.

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Old 10-04-2008, 05:24 PM   #5
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Calculating load - 240 load question


Yep. Interesting when ya think about it, huh?
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Old 10-04-2008, 05:26 PM   #6
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Calculating load - 240 load question


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Now that you say it this way it makes perfect sense to me. The setup where there are 2 single pole breakers bonded together, both switches attached to each other.

Wow a hot tub sure can draw alot of power compared to many 120 appliances.

Thanks
Jamie
Yes, but it will cycle, just like an electric range.

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