5 posts / 0 new
Last post
coverting 240v to 120v

Hi, is there a way to convert a 240vac line so you can run 120vac appliances off of it? Thanks

Re: coverting 240v to 120v

Can you expand on details?

Re: coverting 240v to 120v

Yup, need a few details but yes, very possible.

Re: coverting 240v to 120v

Yes it is possible, how depends an the type and wiring of the 240v circuit.

Re: coverting 240v to 120v

If there's a neutral wire (not just a ground), it's easy. The voltage will be 120V between ONE (either) of the hot wires and the neutral.

The breaker for the circuit must be properly sized for the SMALLEST wire in the circuit. So if the 240V circuit is a re-used dryer outlet, which is typically 30A, and you are connecting 12 gauge wire to it, you'll either need to replace the 30A breaker with a 20A one, or you'll need to install a sub-panel at the end of the 240V circuit. Example:

[30A 2-pole Breaker]=======Hot=[1-pole 20A Breaker]=12 ga==+
| | |
| 120V [120V Appliance]
| | |
240V -----Neutral-+--------12 gauge--------+
| | |
| | +--------14 gauge--------+
| | |
| 120V [120V Receptacle or lights]
| | |
[30A 2-pole Breaker]=======Hot=[1-pole 15A Breaker]=14 ga==+

You didn't hear this from me: it's also 120V between ONE of the hot wires and the ground. But to use the ground as a neutral is not permissible under any electrical code.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.