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MHH · Nov 26, 2006, 10:09 AM

I have a 220VAC single phase 30 amp circuit that I would like to split into two 110VAC circuits. The 220VAC circuit has 3 wires and if I measure across the two main terminals I get the 220VAC and if I measure between a main terminal and what appears to be ground, I get the 110VAC. If I take one of the wires from one of the main terminals and what appears to be the ground of the 220vac circuit then how do I get a ground for the newly created 110VAC? Can I run a separate ground from another VAC 110 outlet and connect to the new 110VAC circuit?

Thanks

labman · Nov 26, 2006, 10:58 AM

You should have a black, red, white, and bare or green. If so, you can do it using the white as the neutral for both circuits. It is a shortcut I don't like, but OK by code.

tkrussell · Nov 26, 2006, 01:16 PM

Be sure you understand Labman correctly, he is using the proper terminology, you need a neutral AND a ground. You only mention "ground".

If the "ground" wire you have is insulated, then it can be used as a neutral. If the wire is bare it can only be a ground.

What Labman is referring to is to share a Neutral wire with two 120 volt circuits, which is allowed, but does have issues, we can get into later.

What I need from you is detail on the "ground" wire you have. Don't mean to be nitpicky, but there is a huge difference between Neutral and Ground.

Neutrals are currect carrying conductors, and if this is not correctly, or if you do not understand, you can end up sending current through-out your electrical system's grounding.

Running another wire from another outlet is never allowed. Especially if your not sure what you are running , either a ground, or a neutral.

Where are you located?

What type of cable is this wiring?

Is the "ground" insulated or bare?

I do not believe you have enough information to continue with what you are proposing until we get more detail from you.

MHH · Nov 26, 2006, 07:08 PM

Thanks for the quick responses. I checked again and unfortunately it is only a 3 wire cable for the 220VAC circuit. It has a white, black and a bare ground in a orange shield. This is what has thrown me as I was expecting a 4 wire cable for the 220, two hots , a neutral and a ground. I haven't done a voltage or continuity check from the ground of the 220 and a 110 circuit to see if there is voltage between the two or if they are indeed both at ground potential. Before I did any thing I wanted to see what the experts had to say. Thanks for all the help

Originally Posted by tkrussell

Be sure you understand Labman correctly, he is using the proper terminology, you need a neutral AND a ground. You only mention "ground".

If the "ground" wire you have is insulated, then it can be used as a neutral. If the wire is bare it can only be a ground.

What Labman is referring to is to share a Neutral wire with two 120 volt circuits, which is allowed, but does have issues, we can get into later.

What I need from you is detail on the "ground" wire you have. Don't mean to be nitpicky, but there is a huge difference bewteen Neutral and Ground.

Neutrals are currect carrying conductors, and if this is not correctly, or if you do not understand, you can end up sending current through-out your electrical system's grounding.

Running another wire from another outlet is never allowed. Especially if your not sure what you are running , either a ground, or a neutral.

Where are you located?

What type of cable is this wiring?

Is the "ground" insulated or bare?

I do not beleive you have enough information to continue with what you are proposing until we get more detail from you.

Swigo · May 15, 2018, 01:05 PM

I have a 220 vac line going to a GFI box for my hot tub. I want to tap off one side of my 220 vac in the box to go to a new outlet. I plan on connecting the 110 vac to either the Black wire or the Red wire Plus the White neutral wire and the Bare wire. (all before the GFI breaker.) I will then install a GFI on my 110 vac outlet.
Does that sound right?
Thanks,
Dennis

ma0641 · May 15, 2018, 03:04 PM

NEC requires a dedicated circuit for a spa/hot tub. Any outlets located at the spa must be on a separate GFCI circuit.

Stratmando · May 18, 2018, 09:36 AM

You need a Neutral AND Ground. Ground is Not to carry Current, If you did have a ground and Neutral, a Red and Black can Share a Neutral(a Multi Circuit), they need to Be Next to each other on Panel, Opposite phases, on a 2 Pole Breaker.
Being on opposite phases, If 1 circuit draws 20 amps, and other draws 15 amps, the Neutral carries the difference(5 amps), if they were on same phase, Neutral would carry current of both(35 Amps)