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  #1  
Old 03-01-2012, 10:02 AM
FatBaldGuy FatBaldGuy is offline
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Getting 110 volts from a 220 volt outlet

My daughter just had to purchase a new washer and dryer combo since her old one died. The problem is that the old one, which came with the house, is a combination unit, and had only a single 220v plug which ran both the washer and dryer. The closet where the unit was installed has only a single 220v outlet and no 110v, which the new washer needs.

I know that 220v power is actually 2 legs of 110v each, and that in theory you could open the box and run a 100v outlet by connecting to one leg of the 220v supply, but my gut instinct tells me that would violate the building codes (this is in the state of WA if that makes any difference).

My question is twofold. First, would that actually be a code violation to piggyback a 110v wall outlet off of a 220v outlet. Second, is there such a thing as an adapter plug, that could plug into the existing outlet and split the power into 2 plugs for 220 and 110? I tried Googling, but only came up with travel converters for international use.
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Old 03-01-2012, 10:10 AM
beowulff beowulff is offline
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IANAE, but I *think* it would be kosher to disconnect one leg at the breaker, wrap white tape around it (to indicate that it is now a neutral), and connect it to neutral. At the outlet end, you can now replace the outlet with a 110v one, and take the (now neutral) wire and wrap white tape around it, and connect it to the neutral connection of the outlet. Use the existing hot and ground wires.

Last edited by beowulff; 03-01-2012 at 10:11 AM..
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  #3  
Old 03-01-2012, 10:11 AM
jz78817 jz78817 is offline
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yes, it would be a code violation.

http://www.ehow.com/info_12182443_ca...ppliances.html
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  #4  
Old 03-01-2012, 10:15 AM
gotpasswords gotpasswords is offline
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I'm assuming a stacked set? And it all runs on 120? Unless the new dryer runs on gas, I think she'll be in for some slow drying.

Ideally, the washer/dryer can be re-configured to run on 240. Or, go back to the store and say "Hey, I need one that runs on 240!"

Otherwise, converting the 240-volt receptacle will need the services of an electrician as the double 30-amp breaker at the main panel will need to be changed to a single 15 or 20 amp, and connecting the fat wires to a normal receptacle is not possible without "pigtailing" them. It will also probably be needed to re-designate one of the hot legs as a ground as a 3-wire dryer circuit is two hot legs and a neutral with no ground. Newer 4-wire circuits have the two hots, a neutral and a ground. Easy stuff for a qualified electrician, but not something I'd advise a home handyperson to attempt.

Last edited by gotpasswords; 03-01-2012 at 10:17 AM..
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  #5  
Old 03-01-2012, 10:21 AM
FatBaldGuy FatBaldGuy is offline
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Quote:
Originally Posted by gotpasswords View Post
I'm assuming a stacked set? And it all runs on 120? Unless the new dryer runs on gas, I think she'll be in for some slow drying.

Ideally, the washer/dryer can be re-configured to run on 240. Or, go back to the store and say "Hey, I need one that runs on 240!"

Otherwise, converting the 240-volt receptacle will need the services of an electrician as the double 30-amp breaker at the main panel will need to be changed to a single 15 or 20 amp, and connecting the fat wires to a normal receptacle is not possible without "pigtailing" them.
No, the old unit had only a single 220v plug, which was split inside the unit to provide power to the washer and dryer. The new unit has a 220v plug for the dryer and a 110v plug for the washer. The problem is that there is no 110v outlet in the closet.

I know I could buy some parts and build an external adapter with a 220v cord to plug in the outlet, and I could pigtail a 220v and 110v receptacle into a box that would be completely independent of the house wiring, but I was wondering if there is already such a device on the market.
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  #6  
Old 03-01-2012, 10:24 AM
gotpasswords gotpasswords is offline
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Ah. The only real solution will be to have an electrician run a new 120-volt line for the washer then. There's no easy, safe or "legal" way to tap 120 off a 240-volt circuit.

Last edited by gotpasswords; 03-01-2012 at 10:25 AM..
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  #7  
Old 03-01-2012, 10:35 AM
kanicbird kanicbird is offline
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Check your washer, perhaps there is a way to configure it to run on 220
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Old 03-01-2012, 10:39 AM
BubbaDog BubbaDog is offline
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Quote:
Originally Posted by beowulff View Post
IANAE, but I *think* it would be kosher to disconnect one leg at the breaker, wrap white tape around it (to indicate that it is now a neutral), and connect it to neutral. At the outlet end, you can now replace the outlet with a 110v one, and take the (now neutral) wire and wrap white tape around it, and connect it to the neutral connection of the outlet. Use the existing hot and ground wires.
Besides being against code, this action would render the 240 volt circuit useless and if you read the OP what he wants to do is have one 240VAC and one 120VAC available for the washer and the dryer respectively.

The op stated that he needed both a 240V and a 120V circuit.

As gotpasswords stated no legal way to rig the existing plug and rigging an external connection apparatus is a dangerous idea.
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  #9  
Old 03-01-2012, 10:49 AM
beowulff beowulff is offline
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Originally Posted by BubbaDog View Post
The op stated that he needed both a 240V and a 120V circuit.
Where?
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  #10  
Old 03-01-2012, 10:50 AM
J-P L J-P L is offline
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There are adapters available. I have one behind my stove, said stove is using gas and only needs 110 volts to run the clock and other controls.

The adapter plugs into the standard 220 connection behind the stove and the stove's plug connects to it.

I got the adapter at Home Depot in the appliance section.

However, it leave no capability of also connecting another appliance using 220 volts.
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  #11  
Old 03-01-2012, 10:50 AM
johnpost johnpost is offline
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getting 110V off of 220V is a code violation.

if the washer could run on 220V then you would have to split (with a junction box) the 220V run to a dryer receptacle and one for the washer. problem here is that dryer run (maybe 30A) has large sized wire and this would need to be carried through to the receptacle used for the washer and a 30A receptacle used for the washer and the washer plug/cordset changed to fit that 30A receptacle. cost on this would compare to running a new 110V circuit.

if the laundry is on the first floor above a basement or crawl space then it is not expensive or difficult to run a 110V circuit for it.
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  #12  
Old 03-01-2012, 11:30 AM
VOW VOW is offline
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When we lived in Germany, the current there is 220v. If we wanted to use our US appliances, we had to buy transformers. The bigger the appliance, the bigger the transformer. I've forgotten more about amps and watts than I ever really wanted to know.

From experience, we know if you plug your 110v into a 220v with no transformer, you'll destroy your appliance--either immediately or eventually.

Go online and see if the appliance has an adaptor kit for 220v. Some of those compact machines can operate on 110-220, but you'll need to install another cord.

If the appliance doesn't feature that option, do one of two things:
(1) Take it back to the store and get one that uses only 220v, or
(2) Call an electrician.

If your seat-of-the-pants remedy (meaning, you don't want to pay an electrician) fails and the house burns down, the insurance company will NOT PAY.


~VOW
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  #13  
Old 03-01-2012, 11:44 AM
jz78817 jz78817 is offline
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Quote:
Originally Posted by VOW View Post
When we lived in Germany, the current there is 220v. If we wanted to use our US appliances, we had to buy transformers. The bigger the appliance, the bigger the transformer. I've forgotten more about amps and watts than I ever really wanted to know.

From experience, we know if you plug your 110v into a 220v with no transformer, you'll destroy your appliance--either immediately or eventually.
~VOW
the situations are different, though. In .de (and presumably all other 230VAC countries) at each receptacle you have 230V phase, neutral, and possibly ground (two or three pins.) US residential power is split-single-phase, and the 240VAC is 120V phase, 120V inverted phase, neutral, and possibly ground (three or four pins.)

plus, most 230VAC countries also use 50 Hz, so things with induction motors might not run as well even if they can handle the voltage.
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  #14  
Old 03-01-2012, 11:45 AM
FatBaldGuy FatBaldGuy is offline
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Thanks for all the replies. I guess she and her husband will have to bite the bullet and call an electrician.

VOW, I know that you can't run a 110v appliance directly from a 220v source, but in the US, a 220v outlet actually consists of 2 110v legs, so that in a 220v outlet you have one neutral wire and 2 110v wires, so you can technically get 110 volts by connecting to only one leg of the circuit.

However, as others have posted here, this is a code violation and could cause problems if not done properly.
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  #15  
Old 03-01-2012, 12:14 PM
johnpost johnpost is offline
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a 220V outlet can have only 2 hot wires. depending on when the installation was done and the needs of the device it might also have a grounding wire or a grounding wire along with a neutral wire.
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  #16  
Old 03-01-2012, 02:13 PM
t-bonham@scc.net t-bonham@scc.net is offline
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Originally Posted by FatBaldGuy View Post
VOW, I know that you can't run a 110v appliance directly from a 220v source, but in the US, a 220v outlet actually consists of 2 110v legs, so that in a 220v outlet you have one neutral wire and 2 110v wires, so you can technically get 110 volts by connecting to only one leg of the circuit.
No, not always. Many older dryer outlets were wired only for 220V, with only the 2 hot wires -- no neutral. From such an outlet, you can only get 220V (unless you use the ground as part of the circuit -- an illegal & dangerous procedure).

easy way to check is to look at the outlet -- does it have 4 connectors, or only 3?
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  #17  
Old 03-01-2012, 02:16 PM
slitterst slitterst is offline
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One possible solution is to replace the 220v outlet with a subpanel with 220 and 110 breakers. From the subpanel you would run a new 220v outlet and a new 110v outlet.

This would still require an electrician. But if the guy does his math right, it may be the only way to save from pulling new wires.
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  #18  
Old 03-01-2012, 02:41 PM
engineer_comp_geek engineer_comp_geek is online now
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Originally Posted by slitterst View Post
One possible solution is to replace the 220v outlet with a subpanel with 220 and 110 breakers. From the subpanel you would run a new 220v outlet and a new 110v outlet.

This would still require an electrician. But if the guy does his math right, it may be the only way to save from pulling new wires.
You don't want to do that. The existing wire gauge is too small to feed a sub-panel.
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  #19  
Old 03-01-2012, 03:23 PM
thelabdude thelabdude is offline
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I think current codes call for new installations to have 4 prong cords and outlets for 240 appliances. Unless the original cable was 10-3 with ground, you may need to run a new cable. Depending how much unfinished space you have, that might or might not be a problem.

Does code forbid a subpanel on a 30 amp circuit? I am guessing that is what is there.
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Old 03-01-2012, 04:42 PM
ZenBeam ZenBeam is offline
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Would it be illegal/against code to modify the washer-dryer pair so that the washer cord is fed from the dryer, rather than plugging directly into the wall? Maybe add a 110 V outlet to the dryer, to plug the washer into? I know I've seen (long ago) a 110 outlet on an electric stove, and more recently, outlets on the back of stereo equipment. (This assumes there's a four-prong plug for the dryer.)
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  #21  
Old 03-01-2012, 04:52 PM
FatBaldGuy FatBaldGuy is offline
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Originally Posted by ZenBeam View Post
Would it be illegal/against code to modify the washer-dryer pair so that the washer cord is fed from the dryer, rather than plugging directly into the wall? Maybe add a 110 V outlet to the dryer, to plug the washer into? I know I've seen (long ago) a 110 outlet on an electric stove, and more recently, outlets on the back of stereo equipment. (This assumes there's a four-prong plug for the dryer.)
I don't know about illegal/against code, but I'm sure not going to do anything to mess up the warranty on her brand new washer/dryer. Looks like running a 110v circuit to the laundry closet is going to be the answer.
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Old 03-01-2012, 06:17 PM
BubbaDog BubbaDog is offline
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Originally Posted by beowulff View Post
Where?
Right here
Quote:
Originally Posted by FatBaldGuy
[snip]is there such a thing as an adapter plug, that could plug into the existing outlet and split the power into 2 plugs for 220 and 110?[snip]
Granted he didn't come out and say he needed the circuit but his question suggested he needed both. Hopefully you didn't ask that question because I referred to present day voltage standards 240/120 compared to older 220/110. That's a po-tay-to / po-tot-toe issue that I assumed the reader would understand.

And I should repeat that your suggestion, while possibly functional, isn't code and could possibly be dangerous to future tenants.

I've never seen anything like J-P-L has on his stove other than a portable generator adapter which would be a bad idea to use on a large appliance.
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Old 03-01-2012, 07:05 PM
ZenBeam ZenBeam is offline
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I don't know about illegal/against code, but I'm sure not going to do anything to mess up the warranty on her brand new washer/dryer.
Oops. Good point.
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Old 03-01-2012, 07:05 PM
thelabdude thelabdude is offline
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I think outlets on stoves are common. Ours has a 120V one. I think when our house was built in 1970, the 2 conductor with ground SE met code for the stove.

I wonder what it would have cost to repair the old unit?
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  #25  
Old 03-01-2012, 07:32 PM
Chefguy Chefguy is offline
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Originally Posted by engineer_comp_geek View Post
You don't want to do that. The existing wire gauge is too small to feed a sub-panel.
Well, not really, unless there is a code cite that prohibits a 30 amp sub-panel. As long as you're not over-protecting the washer circuit, it would probably work okay.
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  #26  
Old 03-01-2012, 07:45 PM
J-P L J-P L is offline
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this is the adapter that I have
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Old 03-01-2012, 09:51 PM
engineer_comp_geek engineer_comp_geek is online now
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Well, not really, unless there is a code cite that prohibits a 30 amp sub-panel. As long as you're not over-protecting the washer circuit, it would probably work okay.
Even if code permitted it, it's a really really bad thing to do.

The whole point behind a 220 outlet is that you need to plug something into it that needs more power than you can get from a 110 outlet. This is why you can't multi-drop 220 outlets on the same circuit like you can 110 outlets. For the same reason, you can use #12 wire and a 15 amp 110 outlet and mulit-drop them, but if you use that same #12 wire and a 20 amp 110 outlet you can't, even though internally the only difference between a 15 amp and 20 amp outlet is the little extra tab on the side of the connector (they both have exactly the same current carrying capability internally). The idea is that if you have something designed for more power it's kinda expected that you are going to draw more power out of it.

Because the wire from your new sub-panel is only rated for 30 amps, your sub-panel has to be rated for 30 amps. But if you plug in a dryer you can expect that it very well might draw close to 30 amps. Just for giggles lets say it only draws 20 amps. Add to that 15 amps from the 110 circuit and you're over the 30 amp breaker limit. Basically, the major flaw with this design is you've made it fairly likely to blow the sub-panel's main breaker any time both outlets are used.

Hence, it's a very bad design.

This is also the underlying principle as to why the OP's only real choice is to have a new, separate 110 line run for the washer.

Now, if the existing circuit were rated for 50 amps, you could put in a 50 amp panel and run a 30 amp 220 circuit for the dryer and a 15 amp 110 circuit for the washer with no problem. 50 amp circuits for dryers aren't very common though in my experience (at least not around here) so I kinda doubt the OP has one.
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  #28  
Old 03-02-2012, 08:02 AM
thelabdude thelabdude is offline
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Interesting, the old combo ran fine on the existing wiring and breaker, but the new one won't? Do we have data showing the new combo draws more current than the old? Isn't the EPA forcing more efficient appliances?

One consideration is balance. If the old washer motor was 240, it would have pulled from both legs equally. A 120 motor only pulls from one.

A few years ago I added a sub panel. It runs off a 50 amp breaker and I have breakers adding up to 150 amps in it. Nothing has blown yet.
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  #29  
Old 03-02-2012, 08:39 AM
gotpasswords gotpasswords is offline
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Originally Posted by J-P L
this is the adapter that I have
Interesting, yet frightening gizmo! It's worth noting that this adapter plugs into a 50-amp circuit, so whatever you plug into it will have effectively zero overload protection.

What makes this particular thing possible is that it plugs into a 4-wire receptacle, so separate neutral and ground are available. But, due to the lack of overload protection, I'd rather avoid using it - the appliance's power cord will more likely melt away before the 50-amp breaker senses anything wrong.
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Old 03-02-2012, 08:44 AM
J-P L J-P L is offline
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Originally Posted by gotpasswords View Post
Interesting, yet frightening gizmo! It's worth noting that this adapter plugs into a 50-amp circuit, so whatever you plug into it will have effectively zero overload protection.

What makes this particular thing possible is that it plugs into a 4-wire receptacle, so separate neutral and ground are available. But, due to the lack of overload protection, I'd rather avoid using it - the appliance's power cord will more likely melt away before the 50-amp breaker senses anything wrong.
If you read the specification, you'll notice that the device contains a 15 amps internal fuse.
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  #31  
Old 03-02-2012, 08:50 AM
Chefguy Chefguy is offline
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Originally Posted by engineer_comp_geek View Post
Even if code permitted it, it's a really really bad thing to do.

The whole point behind a 220 outlet is that you need to plug something into it that needs more power than you can get from a 110 outlet. This is why you can't multi-drop 220 outlets on the same circuit like you can 110 outlets. For the same reason, you can use #12 wire and a 15 amp 110 outlet and mulit-drop them, but if you use that same #12 wire and a 20 amp 110 outlet you can't, even though internally the only difference between a 15 amp and 20 amp outlet is the little extra tab on the side of the connector (they both have exactly the same current carrying capability internally). The idea is that if you have something designed for more power it's kinda expected that you are going to draw more power out of it.

Because the wire from your new sub-panel is only rated for 30 amps, your sub-panel has to be rated for 30 amps. But if you plug in a dryer you can expect that it very well might draw close to 30 amps. Just for giggles lets say it only draws 20 amps. Add to that 15 amps from the 110 circuit and you're over the 30 amp breaker limit. Basically, the major flaw with this design is you've made it fairly likely to blow the sub-panel's main breaker any time both outlets are used.

Hence, it's a very bad design.

This is also the underlying principle as to why the OP's only real choice is to have a new, separate 110 line run for the washer.

Now, if the existing circuit were rated for 50 amps, you could put in a 50 amp panel and run a 30 amp 220 circuit for the dryer and a 15 amp 110 circuit for the washer with no problem. 50 amp circuits for dryers aren't very common though in my experience (at least not around here) so I kinda doubt the OP has one.
True enough. It's not the best solution, and I wouldn't ordinarily recommend it, although sometimes necessity dictates different solutions. I've done similar things in my past to come up with a workable setup, but with the understanding that it's temporary. A user would probably have to make sure he/she didn't use both appliances at the same time, although I would suspect the main amperage draw is the motor starting amps on both pieces. I don't know what the running load for a dryer is, offhand.
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Old 03-02-2012, 08:55 AM
Satchmo Satchmo is offline
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Originally Posted by gotpasswords View Post
Interesting, yet frightening gizmo! It's worth noting that this adapter plugs into a 50-amp circuit, so whatever you plug into it will have effectively zero overload protection.

What makes this particular thing possible is that it plugs into a 4-wire receptacle, so separate neutral and ground are available. But, due to the lack of overload protection, I'd rather avoid using it - the appliance's power cord will more likely melt away before the 50-amp breaker senses anything wrong.
Well, the specs say it has a "Built-in 15 Amp fuse". So it's probably all right.

Last edited by Satchmo; 03-02-2012 at 08:56 AM.. Reason: ETA ninja'd by 10 minutes. :(
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Old 03-02-2012, 09:44 AM
Crafter_Man Crafter_Man is offline
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you can use #12 wire and a 15 amp 110 outlet and mulit-drop them, but if you use that same #12 wire and a 20 amp 110 outlet you can't, even though internally the only difference between a 15 amp and 20 amp outlet is the little extra tab on the side of the connector (they both have exactly the same current carrying capability internally). The idea is that if you have something designed for more power it's kinda expected that you are going to draw more power out of it.
Sorry for the hijack, but...

When I fixed up our basement, I used #12 wire for all the receptacles. All of the receptacles are 20 amp, and I have multiple receptacles on the same circuit. Is this a code violation? Do I need to replace all my receptacles with 15 amp ones?
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Old 03-02-2012, 10:07 AM
BubbaDog BubbaDog is offline
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this is the adapter that I have
That device has CSA certification but not UL implying it might be Canadian product. Also, on the page of your cite somebody asks if it is available in the USA and got no reply.

A search of inventory to my local stores turns up no results.

Did you buy it in the USA? If so, how long ago. It appears as if it is not available in the USA.
(Edit - I see by your profile that you are in Canada) Maybe Canada has coded it as OK but USA probably hasn't)

Anybody - go to the site and put your zip code into the search box and see if your local HD has one.

I'm curious to see if these are still sold in the USA.

Last edited by BubbaDog; 03-02-2012 at 10:11 AM.. Reason: new info
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Old 03-02-2012, 10:34 AM
engineer_comp_geek engineer_comp_geek is online now
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Originally Posted by Crafter_Man View Post
Sorry for the hijack, but...

When I fixed up our basement, I used #12 wire for all the receptacles. All of the receptacles are 20 amp, and I have multiple receptacles on the same circuit. Is this a code violation? Do I need to replace all my receptacles with 15 amp ones?
Yes, that's a code violation. You need to install 15 amp receptacles.

You can keep the #12 wire of course, and you can even keep the 20 amp breaker. The 20 amp breaker with 15 amp receptacles may seem like it should be a code violation, but the NEC allows it since 15 amp receptacles are actually usually identical to 20 amp receptacles internally (and 15 amp receptacles have to be able to withstand 20 amps for UL).
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Old 03-02-2012, 10:48 AM
Crafter_Man Crafter_Man is offline
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Originally Posted by engineer_comp_geek View Post
Yes, that's a code violation. You need to install 15 amp receptacles.

You can keep the #12 wire of course, and you can even keep the 20 amp breaker. The 20 amp breaker with 15 amp receptacles may seem like it should be a code violation, but the NEC allows it since 15 amp receptacles are actually usually identical to 20 amp receptacles internally (and 15 amp receptacles have to be able to withstand 20 amps for UL).
Thanks. But now I'm pissed because I have to replace all my receptacles now. What a stupid rule.
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Old 03-02-2012, 12:09 PM
Satchmo Satchmo is offline
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Originally Posted by BubbaDog View Post
That device has CSA certification but not UL implying it might be Canadian product. Also, on the page of your cite somebody asks if it is available in the USA and got no reply.

A search of inventory to my local stores turns up no results.

Did you buy it in the USA? If so, how long ago. It appears as if it is not available in the USA.
(Edit - I see by your profile that you are in Canada) Maybe Canada has coded it as OK but USA probably hasn't)

Anybody - go to the site and put your zip code into the search box and see if your local HD has one.

I'm curious to see if these are still sold in the USA.
Doesn't look like it's available in the U.S.
I logged into my local store and searched for both the SKU and Model number, the only suggested similar items are for RV converters/extentions.
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  #38  
Old 03-02-2012, 01:02 PM
kanicbird kanicbird is offline
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Thanks. But now I'm pissed because I have to replace all my receptacles now. What a stupid rule.
I won't tell anyone if you won't
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  #39  
Old 03-02-2012, 01:08 PM
kanicbird kanicbird is offline
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Originally Posted by engineer_comp_geek View Post

Because the wire from your new sub-panel is only rated for 30 amps, your sub-panel has to be rated for 30 amps. But if you plug in a dryer you can expect that it very well might draw close to 30 amps. Just for giggles lets say it only draws 20 amps. Add to that 15 amps from the 110 circuit and you're over the 30 amp breaker limit. Basically, the major flaw with this design is you've made it fairly likely to blow the sub-panel's main breaker any time both outlets are used.

Hence, it's a very bad design.
It's actually a very normal design. Many panels have circuit capacity beyond the main breaker capacity. The idea is chances are you are not going to draw all circuits to the max all the time.

In this case, a washer/dryer it is not unusual to just run one at a time, though some people prefer to do multiple loads of laundry which could cause problems.

In the above case, though generally not recommended, I would strongly consider a high capacity extension cord for the washer, or perhaps a hole in the wall can allow the washer cord to poke through to a different outlet.
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  #40  
Old 03-02-2012, 07:28 PM
thelabdude thelabdude is offline
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Quote:
Originally Posted by t-bonham@scc.net View Post
No, not always. Many older dryer outlets were wired only for 220V, with only the 2 hot wires -- no neutral. From such an outlet, you can only get 220V (unless you use the ground as part of the circuit -- an illegal & dangerous procedure).

easy way to check is to look at the outlet -- does it have 4 connectors, or only 3?
How old? The first dryer my mother had in the 50's had a 3 wire cord. Yes using the same bare wire for ground and neutral for the 120 components was a bad practice. Not only was it common, it met code until fairly recently, perhaps the 2005 revision.

Now, I doubt we can say what is possible until we know how many wires in the cable, what size, and the loads of the new washer and dryer.
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  #41  
Old 03-02-2012, 08:10 PM
engineer_comp_geek engineer_comp_geek is online now
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Quote:
Originally Posted by kanicbird View Post
Many panels have circuit capacity beyond the main breaker capacity. The idea is chances are you are not going to draw all circuits to the max all the time.
Yes, many panels do and that's perfectly acceptable. The key here is the second sentence I quoted above, that chances are you are not going to draw all circuits to the max. The NEC considers 220 circuits (and 20 amp 110 circuits) to be dedicated. The NEC basically wants you to always consider these dedicated circuits as drawing the max current, even though in the real world they often aren't.

If thelabdude's 50 amp panel feeds 150 amps worth of regular 15 amp outlets, that's perfectly fine. If it feeds two 30 amp 220 circuits it's not acceptable, even though that's only 60 amps and the other way was 150. It's all in how you consider those dedicated circuits to be loaded. It's a bit of a subtle distinction but it's the point the NEC is trying to make.
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  #42  
Old 09-24-2013, 02:00 AM
smo7 smo7 is offline
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Would these cables work like home depot device

http://www.amazon.com/Conntek-YL1430...ef=pd_sim_hi_3

or
http://www.amazon.com/Coleman-Cable-...5RYTQXE8GX16X4

I would like use the unused 220v Gas Dryer in laundry room for 2nd refrigerator.
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  #43  
Old 09-24-2013, 02:18 AM
engineer_comp_geek engineer_comp_geek is online now
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Quote:
Originally Posted by smo7 View Post
http://www.amazon.com/Conntek-YL1430...ef=pd_sim_hi_3

or
http://www.amazon.com/Coleman-Cable-...5RYTQXE8GX16X4

I would like use the unused 220v Gas Dryer in laundry room for 2nd refrigerator.
Those types of things are intended to be used with portable generators for temporary power. They are not intended for permanent installations. Powering a fridge with one of those would be a code violation.

Have an electrician run a 120 circuit to an outlet where you want the fridge.
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  #44  
Old 09-25-2013, 04:26 AM
usedtobe usedtobe is offline
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I'm guessing the last 2/3 gets into legalities - where what is legal.

Would it be possible to install a junction box where the current 240 outlet is?

If so, is it legal (it really should be) to run a 240 to one outlet and 120 to another, all in the same closet. The 4 or 6 ga wire would run about 3' - hardly bank-busting, esp. compared to what electricians charge.

This assumes that there are at least 3 conductors to existing outlet:
Black
Black
White

Don't be surprised if there is a white being used as ground. It may even be a bare wire, but it IS connected to neutral.

I owned a house built in 1919 - when re-wired in the early 1960's BY THE UTILITY COMPANY (they were burying all overhead lines and automatically upgraded everybody to 200A service.
They did NOT sink grounding rods - it used ground-to-neutral.
The 1979 house also uses ground-to-neutral.

your house is very likely to use ground to neutral - to confirm, remove the cover of your breaker box - the bare wires are ground - they should all go to the same bar - that bar is your grounding buss. Five will get you ten there is a white wire attached to the ground buss - congratulations! Your home is grounded to neutral.
Using that fact, even if the only other wire to the existing 240 is bare ("ground"), you would be doing absolutely nothing more or less dangerous than already exists by using the bare to pick up 120.

Using a separate junction box will make it look nice and clean, should you ever want to sell.

For those who worry excessively about code: look into "homeowner permits" - in CA at least, you are allowed to do things to your own house which a stranger would need a license to do.
The permit process is how the State enforces this - to "pull a permit" requires a license. Unless it is the owner doing the work, in which case he/she can pull a "owner.occupier" permit.

Never messed with it - didn't want to have to stop work at points A, B and C and wait for an over-worked, under-staffed Inspector to look at it and say "yep, that's a pipe, all right!".

Last edited by usedtobe; 09-25-2013 at 04:30 AM..
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  #45  
Old 09-25-2013, 05:56 AM
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Quote:
Originally Posted by usedtobe View Post
If so, is it legal (it really should be) to run a 240 to one outlet and 120 to another, all in the same closet.
It's not to code, and it shouldn't be. When you are using 240 volts, it is usually because you can't get enough power out of a 120 volt circuit. Therefore, 240 volt circuits are expected to be dedicated to a single outlet. That's the reason behind not allowing 240 volt and 120 volt outlets on the same circuit. It's the same reason that a 20 amp 120 volt outlet has to be on its own dedicated circuit as well.

Quote:
Originally Posted by usedtobe View Post
This assumes that there are at least 3 conductors to existing outlet:
Black
Black
White
It's more common to have a black and a red for the two hots so that you can differentiate between them.

Quote:
Originally Posted by usedtobe View Post
Don't be surprised if there is a white being used as ground. It may even be a bare wire, but it IS connected to neutral.
In newer wiring, white will only be neutral. It should never be ground. Bare or green should be ground. In older wire where there was no dedicated ground, the neutral was often used as the safety ground for appliances.

The problem with using the neutral as a safety ground is that if the neutral wire breaks and you turn on the appliance on, the case becomes electrically hot. It requires only a single point of failure for a dangerous condition to occur. With a separate safety ground, if the neutral breaks, the appliance just stops working. It requires multiple faults to occur before you end up with a dangerous condition like the case becoming electrically hot.

Quote:
Originally Posted by usedtobe View Post
I owned a house built in 1919 - when re-wired in the early 1960's BY THE UTILITY COMPANY (they were burying all overhead lines and automatically upgraded everybody to 200A service.
They did NOT sink grounding rods - it used ground-to-neutral.
The 1979 house also uses ground-to-neutral.

your house is very likely to use ground to neutral - to confirm, remove the cover of your breaker box - the bare wires are ground - they should all go to the same bar - that bar is your grounding buss. Five will get you ten there is a white wire attached to the ground buss - congratulations! Your home is grounded to neutral.
Using that fact, even if the only other wire to the existing 240 is bare ("ground"), you would be doing absolutely nothing more or less dangerous than already exists by using the bare to pick up 120.
I'm not sure what you are calling "grounded to neutral" here. In older homes there was no safety ground. The neutral was used as the safety ground. The neutral from the fuse/breaker box was tied to the cold water pipe to make the connection to earth ground. This served two purposes. First, the cold water pipe was present in pretty much every house and made a convenient common point of ground. Second, since people commonly come in contact with water and water is reasonably conductive, you don't want your water system to be at anything other than electrical ground potential. Grounding to the water pipe insured that both the electrical and the water systems were both referenced to the same earth ground.

In a modern house, there is a separate safety ground. The safety ground is connected to the neutral at the breaker box, and both are connected to earth ground. After the introduction of plastic pipe, the cold water pipe could no longer be relied on as an earth ground connection, so a separate grounding rod is now required. But, you still want your water system to be electrically grounded to the same ground that your electrical system is, so you are also required to connect the neutral and ground to the cold water pipe as well.

In both cases, the neutral is connected to earth ground.

Quote:
Originally Posted by usedtobe View Post
Using a separate junction box will make it look nice and clean, should you ever want to sell.
A junction box would make it look pretty, but it still wouldn't be to code. That could be an issue when you try to sell the house.

Quote:
Originally Posted by usedtobe View Post
For those who worry excessively about code: look into "homeowner permits" - in CA at least, you are allowed to do things to your own house which a stranger would need a license to do.
The permit process is how the State enforces this - to "pull a permit" requires a license. Unless it is the owner doing the work, in which case he/she can pull a "owner.occupier" permit.

Never messed with it - didn't want to have to stop work at points A, B and C and wait for an over-worked, under-staffed Inspector to look at it and say "yep, that's a pipe, all right!".
I have no idea what the rules are in CA, and the rules do vary from state to state (and sometimes even from city to city). However, the stuff in the national electrical code was put in there for a reason and you want to do things right.

If you circumvent the code and permit process you can also expose yourself to some hefty liability. If some sort of fault happens later, and causes a fire, for example, the insurance company can point to the wiring and say that whoever did the wiring has to pay for the damages because the wiring wasn't done to code. Even if the improper wiring didn't cause the fire, it can be very difficult to defend against in court simply because the insurance company's lawyers only have to point to the national electrical code to prove their side. If you get things inspected, then you can always say that you did your best and the inspectors even passed it, which gets you off of the liability hook. If you didn't get it inspected but it's still done to code, then you at least have that on your side and the insurance company can't as easily dump the financial responsibility into your lap.
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Old 09-25-2013, 06:50 AM
HoneyBadgerDC HoneyBadgerDC is offline
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I recently bought a GFI panel for my jacuzzi. It has a seperate circuit for a 20 amp 110 volt plug built into it. $165.00. The circuit from the main panel to the GFI is rated at 50 amps @ 220volts.
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  #47  
Old 09-25-2013, 09:41 AM
johnpost johnpost is offline
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in lots (most in the USA) of places repairing/replacing existing wiring/devices(switches, receptacles, ...) can be done to the electrical code at the time it was put in; though it might leave performance or safety at a level lower than which you would want.

if you change or add to the electrical system then it must be done to the current electrical code.

if you violate the code there is danger to other people. other people besides yourself, especially subsequent homeowners, will not know of your violations and may die because of it.
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  #48  
Old 09-25-2013, 12:09 PM
JFLuvly JFLuvly is offline
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Just for the record 240V is not what the dryer motor runs off of, it is a 120V motor. The power coming into the dryer does not magically come together inside, it is two separate circuits. One circuit usually feeds the motor and timer and the other circuit feeds the heating elements. Each leg draws around 21-23 amps during operation, but inrush currents can exceed 30A. Running a washer on the same circuit as the dryer while the dryer is running would most definitely pop the 30A breaker. The 240V circuit delivers higher amperage, using thicker wire to appliances that need two high amperage separate 120V circuits.
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  #49  
Old 09-25-2013, 12:25 PM
engineer_comp_geek engineer_comp_geek is online now
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Quote:
Originally Posted by JFLuvly View Post
The power coming into the dryer does not magically come together inside, it is two separate circuits. One circuit usually feeds the motor and timer and the other circuit feeds the heating elements.
Dryer designs vary. Most of the ones that I have seen use 120 volts for the motor and 240 volts for the heating elements. This arrangement allows the dryer to be used on both 120/240 systems and the less common 120/208 systems. (ETA: though obviously the heating will be reduced on the 208 systems, requiring longer drying times)

Last edited by engineer_comp_geek; 09-25-2013 at 12:26 PM..
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Old 09-25-2013, 12:33 PM
bob++ bob++ is offline
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I read this and thought how much simpler it is for us in the UK. Our power circuits are all 240 volt except for a dedicated feed to an electric oven if you have one. That feed is also 240 volts but has thicker wires to accommodate the greater load. Each three pin socket is rated at 16 amps but plugs normally have a maximum 13 amp fuse fitted. The three wires (blue, brown and green/yellow) are 'called' live neutral and earth. This is shorthand as all switches are single pole and only cut power to the 'live' side.

The oven feed has to be a direct unbroken line to the breaker board and terminates on the wall near the cooker (The cooker has a double pole switch). There is almost always a standard three pin 16 amp socket on the front of the switch box as well.
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