If I had a piece of gear that needed 208/240V, but none was available at a venue, what are thoughts on an adapter that would have (2) 5-15 Edison plugs to be plugged into different circuit legs? These could then be combined into an appropriate receptacle to access the line-line voltage. Against code? Bad practice? Safety concerns?
120v to 240v Adapter
- Thread starterLPdan
- Start date
My instinct is, is that not a widow-maker?
OK, not as bad as the ones some UK DJs knock up (two UK 13A plugs wired in parallel to draw the full 20A from a dual 13A faceplate) but still dangerous. If one plug is removed, the line voltage from the other leg would travel through the load and make the hot pin live.
OK, not as bad as the ones some UK DJs knock up (two UK 13A plugs wired in parallel to draw the full 20A from a dual 13A faceplate) but still dangerous. If one plug is removed, the line voltage from the other leg would travel through the load and make the hot pin live.
115 volt AC to 220 volt AC
So this might be a stupid question. But I am going to ask it non the less. I have done some searching around and can not find an answer to this. Any help is appreciated. Thanks in advance.Can you take 2 115 VAC circuits and turn them into 220 by just connecting the neutral and the grounds and...
www.controlbooth.com
Great point, didn't consider if one came unplugged. Thanks!
There are a couple of ways... first, if you have 120v in your building, at all.... you have either split-phase 240/120v service or 3 phase 208/120v wye, or 3 phase 480 delta service entering your building (and subsequent step-down transformers)... A electrical contractor can give you an estimate to get the right voltage where you need it. The other way is a portable step-up transformer. I find that back line (guitar amps, bass rigs, drum kits, keyboards) suppliers often have them to power European equipment from USA power sources, so color them "rent-able".
Don't build kludge adapters like you described. I'm sure the link @derekleffew posted has discouraged you from doing so... but in the future ask yourself why you don't see these things done already. The Code-compliant low-hanging fruit was picked long ago...
Last edited:
As others have said, it's a very bad idea, for any number of reasons. One basic reason is that it isn't code-compliant / UL listed.
Should you have a miswired outlet, with hot and neutral reversed, you'd likely create a dead short when you plugged the adapter in (assuming the two supposed neutrals get connected together).
Should you have a breaker trip on either circuit, that circuit would still be live (to some degree) through current sneaking through the adapter and connected device, similar to what happens if one side is unplugged. This can have all sorts of unpleasant ramifications and cause considerable confusion as to why things are working but not working. I'll share a hopefully illustrative anecdote at the end of this post about this sort of thing.
Should the two circuits be on different panels or from two different electrical supplies, the neutrals might not be directly interconnected, and could have noticeable potential differences between them. Connecting them together could lead to large currents flowing through your adapter with no overcurrent protection to keep it safe.
If either side is connected through a GFCI, it will trip in short order.
There indeed are available to buy, rather to my dismay, commercially produced adapters intended for use by RVers with 50A RVs (which use a 120/240V 50A four wire plug, the same as an electric range) to allow them to connect to two 30A (120V only) and/or 20A (standard Edison) plugs and get more power than with a normal 30A to 50A adapter. These suffer from all the problems described including the lack of safety approvals.
My anecdote: I used to rent and live in a neat old farmhouse that had plenty of character and a beautiful setting with a fabulous view of Camel's Hump, the third highest mountain in Vermont. Part of the "character" of this house was a rather variable electric system that had accumulated over the years, ranging from some knob-and-tube circuits connected to screw-in fuses up to newly installed, properly code compliant wiring terminating at a fairly new breaker box. It was a bit of a mess, really. One of the worst bits I discovered was that the kitchen outlet--there was only one besides the fridge outlet--was actually connected to one leg of the fused safety switch for the electric water heater. Among other problems, this meant that one could have a load of 30A through the outlet if the water heater was not heating, but only about 5A if it was heating, before the fuse blew.
One morning, I started a load of laundry, which consumed enough hot water to kick the water heater into operation, and then began to make my breakfast as usual. Partway through heating some milk for cocoa in the microwave, it suddenly stopped with a strange anemic beep and then reset itself. I could press the control buttons for cooking, but whenever I pressed the start button it would beep and reset.
Eventually that evening, after returning home from work, I figured out what was going on. The fuse in the safety switch for the leg the kitchen outlet was connected to had of course blown, but as the water heater was on, there was a sneak path through the heating element to the kitchen outlet. So long as the current being consumed was negligible, something resembling full line voltage was available; but once a load was applied, the voltage dropped. Needless to say, once I discovered what the actual cause was and what the connections were, I grumbled to my landlord, who was equally surprised and promptly corrected the wiring.
I really did enjoy living in that house, but I also saw enough to realize I'd never care to own it myself...not that there was any real possibility of it going on the market anyhow. It had been in my landlord's family for several generations.
Should you have a miswired outlet, with hot and neutral reversed, you'd likely create a dead short when you plugged the adapter in (assuming the two supposed neutrals get connected together).
Should you have a breaker trip on either circuit, that circuit would still be live (to some degree) through current sneaking through the adapter and connected device, similar to what happens if one side is unplugged. This can have all sorts of unpleasant ramifications and cause considerable confusion as to why things are working but not working. I'll share a hopefully illustrative anecdote at the end of this post about this sort of thing.
Should the two circuits be on different panels or from two different electrical supplies, the neutrals might not be directly interconnected, and could have noticeable potential differences between them. Connecting them together could lead to large currents flowing through your adapter with no overcurrent protection to keep it safe.
If either side is connected through a GFCI, it will trip in short order.
There indeed are available to buy, rather to my dismay, commercially produced adapters intended for use by RVers with 50A RVs (which use a 120/240V 50A four wire plug, the same as an electric range) to allow them to connect to two 30A (120V only) and/or 20A (standard Edison) plugs and get more power than with a normal 30A to 50A adapter. These suffer from all the problems described including the lack of safety approvals.
My anecdote: I used to rent and live in a neat old farmhouse that had plenty of character and a beautiful setting with a fabulous view of Camel's Hump, the third highest mountain in Vermont. Part of the "character" of this house was a rather variable electric system that had accumulated over the years, ranging from some knob-and-tube circuits connected to screw-in fuses up to newly installed, properly code compliant wiring terminating at a fairly new breaker box. It was a bit of a mess, really. One of the worst bits I discovered was that the kitchen outlet--there was only one besides the fridge outlet--was actually connected to one leg of the fused safety switch for the electric water heater. Among other problems, this meant that one could have a load of 30A through the outlet if the water heater was not heating, but only about 5A if it was heating, before the fuse blew.
One morning, I started a load of laundry, which consumed enough hot water to kick the water heater into operation, and then began to make my breakfast as usual. Partway through heating some milk for cocoa in the microwave, it suddenly stopped with a strange anemic beep and then reset itself. I could press the control buttons for cooking, but whenever I pressed the start button it would beep and reset.
Eventually that evening, after returning home from work, I figured out what was going on. The fuse in the safety switch for the leg the kitchen outlet was connected to had of course blown, but as the water heater was on, there was a sneak path through the heating element to the kitchen outlet. So long as the current being consumed was negligible, something resembling full line voltage was available; but once a load was applied, the voltage dropped. Needless to say, once I discovered what the actual cause was and what the connections were, I grumbled to my landlord, who was equally surprised and promptly corrected the wiring.
I really did enjoy living in that house, but I also saw enough to realize I'd never care to own it myself...not that there was any real possibility of it going on the market anyhow. It had been in my landlord's family for several generations.
DavidJones
Well-Known Member
Or you could just buy one of these. https://www.quick220.com/
As @TimMc intimates, likely the best way to do it safe and right is with a transformer.
Chris Pflieger
Well-Known Member
How the **** is that ETL listed?!*
Are you suppose to just try random circuits till you find two with opposite polarities?
I'm guessing that box has some relays that kill the other circuit if one goes dead, but still it seems like a bad kludge.
* OK, actually, after going through the process of listing products with both UL and ETL, I know that's a dumb question.
microstar
Well-Known Member
The Quick220 website and company information answers your questions. They have a patent on their safety circuit and the product information tells you to find two outlets of opposite polarity and use the supplied outlet tester to make sure there is no GFCI on those outlets. So yes, you just try random circuits. Looks like they've been around since 1998. What could possibly go wrong?
Similar threads
Vintage Lighting
Radial Leko Lamp Socket Adaptors for Prop Lights
