By code, can you wire a 220v outlet and 110v outlet on the same circuit?

[thefed]

I have a rental that has a dryer as well as overhead lights on the same circuit. Is this up-to-code? I will contact our electrician, but am googling with no success...

 

[travelover]

Generally an electric dryer is on a 30 amp circuit (220v) which means all of the wires in the circuit have to be able to handle 30 amps (10 gauge minimum) . Lights are generally wired with 14 / 12 gauge wire which is only rated for 15/20 amps.

So if the lights are indeed on a 30 amp circuit breaker, there is a fire hazard.

 

[thefed]

I found this: (NEC 210.4(C))

which implies you can mix 110v and 220v, but i am unsure how that really works in relation to travelover's reply....

 

[calmloki]

Generally an electric dryer is on a 30 amp circuit (220v) which means all of the wires in the circuit have to be able to handle 30 amps (10 gauge minimum) . Lights are generally wired with 14 / 12 gauge wire which is only rated for 15/20 amps.

So if the lights are indeed on a 30 amp circuit breaker, there is a fire hazard.

To expand on Travelover's comment, even if the 240v breaker was a 20 amp breaker, consider that it is really two 20 amp 120v breakers linked together. Now you put a 30 amp load on one side of that breaker. Since the breakers are linked together the overloaded side can't throw off - result, serious fire danger as the 12 gauge wire and outlet overheats. Can't see it being ok for code...

 

[Westernskies]

I called tech support for my local utility; a helpful employee with an Indian accent assured me that it was perfectly safe; in fact he sent me the proper wiring diagram:

 

[homestead]

If you wire a 110 off a 220 circuit there is no wire for the return unless
you use the ground which should not be used for current since that would
elevate the ground slightly.

 

[Rambler]

Similar question:

I have a 220v plug (double 30amp breaker) in my garage that I had the electrician set up for an arc welder, in case I ever decided to get/use one on our 2 acre place.

I am kind of doubting now if I will ever have an arc welder, and would prefer a 30amp or maybe even a 50 amp 110/120v plug-in for an as of yet un-purchased RV.

Can I use the double 30amp to breakers and have the 110/120v receptacle installed instead of the 220?

Been wondering about this for a while. I know a bit about electricity, but not about double 30amp breakers and how 220v receptacles are wired.

Thx, R

 

[kumquat]

In my part of the world you can't have multiple anything on a 220 circuit. You can, however, have a sub-panel that is fed by enough 220 current to supply multiple 220 circuits or in Rambler's case multiple 110 circuits, providing other code provisions are met.

 

[travelover]

You can install a small subpanel downstream from the 220volt 30 amp outlet to break down into several 110 volt 15 or 20 amp circuits. This subpanel has a couple 15 or 20 amp breakers in it to protect the smaller gauge wire for regular outlets and lights.

This is how detached garages and work sheds are typically wired where a 220 outlet is also needed for a welder, etc.

I found this book useful, especially for explaining grounding rrequirements:

Amazon.com: Wiring a House (For Pros by Pros) (9781561585274): Rex Cauldwell: Books

 

[Ronstar]

Thefed - I doubt your situation is up to code, and like Travelover and Calmoki are saying - the wire size to the lights has to be up to the breaker capacity.

Rambler - 2 options

1. Install a subpanel on your 220v line and put a 110v breaker in it with a single receptacle for the rv (like Travelover says)

2. Replace your 30 amp 2 pole breaker with a single pole 110v breaker and just not use the second hot wire.

Again, the wire size and breaker have to be up to the level of the total amperage being draw on the circuit. Bookstores have a lot of DIY books that will get you going.

 

[RonBoyd]

I found this book useful, especially for explaining grounding rrequirements:

Amazon.com: Wiring a House (For Pros by Pros) (9781561585274): Rex Cauldwell: Books

or at:

Wiring a House

 

[Nords]

I have a rental that has a dryer as well as overhead lights on the same circuit. Is this up-to-code? I will contact our electrician, but am googling with no success...

To expand on Travelover's comment, even if the 240v breaker was a 20 amp breaker, consider that it is really two 20 amp 120v breakers linked together. Now you put a 30 amp load on one side of that breaker. Since the breakers are linked together the overloaded side can't throw off - result, serious fire danger as the 12 gauge wire and outlet overheats. Can't see it being ok for code...

Even if the inspector lets you get away with it, here's another reason landlords would want to avoid setting themselves up:
One leg of a 220v circuit can trip anytime that it thinks it needs to. (What's even worse is that the metal clip holds the switch to the other breaker switch, so it doesn't really look tripped unless you have a good strong flashlight or you're very familiar with that panel.) If that overloaded 110/220 leg of the breaker trips, then the lights will stop working. The tenant will only notice if they try to turn on the lights. However the dryer will continue to run its 120v motor (spinning the drum) while not being able to heat its 220v coils. You're going to get a call from a very confused (or very ticked off) tenant approximately monthly.

I found this book useful, especially for explaining grounding rrequirements:
Amazon.com: Wiring a House (For Pros by Pros) (9781561585274): Rex Cauldwell: Books

One of the best "how to" books I've ever read. I keep a copy in the garage near our project supplies. We have his plumbing book too.

Last week when I was installing the used stove we'd bought off Craigslist, Rex explained why its neutral was shorted to ground at the terminal block. I knew that the house we'd bought it from was built in 1959 but geez, I thought they'd have updated the wiring at least once in that 50 years. If I hadn't been able to look it up in the book then I would've probably shrugged my shoulders at the stove's weird wiring requirements* and put a grounded neutral in the kitchen.

*[Submarine electrical systems are mostly ungrounded so that a watchstander can check for grounds every hour and hopefully find the problem before the ground turns into a short. So my military electrical experience interferes with my electrical home-improvement skills. My spouse isn't even willing to take hourly ground readings, let alone log them.]

 

[Westernskies]

Similar question:

I have a 220v plug (double 30amp breaker) in my garage that I had the electrician set up for an arc welder, in case I ever decided to get/use one on our 2 acre place.

I am kind of doubting now if I will ever have an arc welder, and would prefer a 30amp or maybe even a 50 amp 110/120v plug-in for an as of yet un-purchased RV.

Can I use the double 30amp to breakers and have the 110/120v receptacle installed instead of the 220?

Been wondering about this for a while. I know a bit about electricity, but not about double 30amp breakers and how 220v receptacles are wired.

Thx, R

If the plug was set up for a 30 amp 220v receptacle, they probably used 3-conductor wire (10-2 or 8-2; plus the ground) You will probably need 4-conductor (10-3 or 8-3, with a ground wire) for the subpanel- 2 hot (red and black), 1 neutral (white) and one ground (bare or green). If it is in conduit, you may be able to use one of the existing conductors to pull two new wires in (use the ground, it's cheaper to replace) if it was wired with shielded cable you may have to pull a new wire (not sure if you can pull a short neutral from a nearby receptacle, or if it needs to go all the way back to the main breaker box?)