240 outlet question

Jul 10, 2008 10 Replies
B

I have a 240VAC twist-lock outlet that was installed to power a repeater/coupler for X-10 home automation gear. I seem to remember (very dimly) that it's against the code to spawn multiple 110VAC outlets downstream from that 240VAC. Since I am out of neutral and ground connections and have no more knockouts left in the circuit box, it would be handy to be able to wire in some new 110VAC outlets to the 240VAC one since the coupler/repeater only uses a few watts.



Does anyone know for sure what the rules are about 110VAC outlets downstream from a 240VAC one? I know one consideration is that the 240AC outlet be connected to a ganged breaker so that if there's a problem, both legs of the circuit will be disconnected if either one trips it. That's how it's set up right now, so if that's the only constraint I should be good to go . . .



TIA


-- Bobby G.


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B

I know of no reason you couldn't add 120V outlets if a neutral is available and the breaker is 15 or 20A.

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R

My garage shop has a 220 branch (with ganged breaker in main house panel), the first device on that branch is a 220 outlet for my table saw and band saw, then there are four more 110 outlets for my work area coming off the 220 outlet (two per side). It passed inspection here, and I like the fact that overloading any of the 110's shuts down all of them. If you are worried then just replace the 220 outlet with a small 4 slot subpanel and move the old 220 and two new 110 branches off that panel.

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B

Just run your 240 VAC line into an auxiliary panel. Then you can run circuits out of it.

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M

It is legal.

You have to have a neutral in the box. You didn't say if the plug was

120/240? If it is 240 only, you will not have a neutral in the box.
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R

Thanks! Yes - neutral and ground are present in the box.

-- Bobby G.

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E

Sometimes, anyway. There are plenty of 3 wire + ground circuits now.

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R

Is that a code requirement or a nice thing to do?

-- Bobby G.

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R

Thanks for the reply, Rick. It sounds as if it's legal, though, to run the

110VAC outlets out of the oversized metal electrical box I mounted the 240VAC outlet in. That would be the ideal solution, effort and cost-wise, that is. This is a "nice to have" but not necessary installation. What do 4 slot subpanels cost should I change my mind (or the inspector change it for me)?

-- Bobby G.

My garage shop has a 220 branch (with ganged breaker in main house panel), the first device on that branch is a 220 outlet for my table saw and band saw, then there are four more 110 outlets for my work area coming off the 220 outlet (two per side). It passed inspection here, and I like the fact that overloading any of the 110's shuts down all of them. If you are worried then just replace the 220 outlet with a small 4 slot subpanel and move the old 220 and two new 110 branches off that panel.

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R

Great, thanks! Everyone seems to agree that 120VAC outlets wired downstream from a 240VAC with neutral on a ganged breaker is codeworthy. I don't know why I thought differently.

-- Bobby G.

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M

Just to double check. Black, Red, White, Green/bare

Don't assume the white is neutral. It may be your other hot.

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