Tapping into 240v A/C line

Old 02-15-15, 03:32 PM
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Tapping into 240v A/C line

I have a subpanel in my basement which has one 240v circuit (40 amp) which powers my central A/C. My basement is really cold in the winter, and I'd like to add a couple of wall space heaters (I'm looking at the Broan units).

I don't have room in the panel for another 240v circuit, but since the A/C and the heating units won't ever be used at the same time, I was thinking of running them all on the same line. There would be 2 wall heaters (at a max 15amps each).

I've wired many 120v circuits, but don't have experience with 240v. Can I wire this like I would a series of regular outlets, i.e., bring the line to the first heater, pass it out to the second heater, and then pass it out to the central A/C?
Old 02-15-15, 03:36 PM
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Welcome to the forums.

You would have to set a sub panel on the A/C line as you cannot connect those heaters directly to a 40A line.
Old 02-15-15, 05:11 PM
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Thanks for the quick response. What is the issue with connecting the heaters directly to the existing 40 amp circuit? The circuit is already in a sub panel - I don't understand why I'd need to connect another sub panel to the existing sub-panel.

If it helps, I attached a photo of the sub panel.

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Old 02-15-15, 06:48 PM
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Where would you obtain proper over current protection? The 40 amp breaker is too large to provide it.
Old 02-15-15, 07:36 PM
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I would replace that existing small subpanel with one a little larger, 12 to 16 spaces, and you can then run two new heater circuits from it in addition to the existing circuits.

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