# Switched Neutral



## brian john (Mar 11, 2007)

electric ninja said:


> Ran into a switched neutral today for the first time.


Switched by an ATS, light switch?



> Put 220 to it and burned some things up.


How did you put 220 to it?



> After explanation, I understand how it works but not seeing any benefit other than confusion. Anyone know what benefit a switched neutral provides?


You need a more in depth explanation, I am lost!


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## static09 (Feb 19, 2012)

i see no application where a switched neutral adds any benefit at all....i never switch the neutral...EVER!!!!!


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## BurtiElectric (Jan 11, 2011)

Breaker? Gas station?


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## BurtiElectric (Jan 11, 2011)

static09 said:


> i see no application where a switched neutral adds any benefit at all....i never switch the neutral...EVER!!!!!


Class one division 1


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## kbatku (Oct 18, 2011)

In knob & tube houses switching the neutral was standard practice. Don't ask me why - it made sense at the time.


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## static09 (Feb 19, 2012)

BurtiElectric said:


> Class one division 1


so there is apps where u would???not saying ther is not just saying in my work*(commerial/residential/service/build) we never do it!!!!!


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## BurtiElectric (Jan 11, 2011)

static09 said:


> so there is apps where u would???not saying ther is not just saying in my work*(commerial/residential/service/build) we never do it!!!!!


Commercial??? Under a gas canopy???


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## brian john (Mar 11, 2007)

static09 said:


> i see no application where a switched neutral adds any benefit at all....i never switch the neutral...EVER!!!!!


What about in an ATS? Very common.
As noted Gas Stations.


When you install a generator do you lift the neutral ground bond in the generator?


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## jza (Oct 31, 2009)

Gas stations switch neutrals?


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## static09 (Feb 19, 2012)

im assuming this has something to do with spark suppress and implosion proof jobs??..might be above my paygrade enlighten us..i was assuming the OP wasnt wiring a gas station lol...my bad


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## static09 (Feb 19, 2012)

jza said:


> Gas stations switch neutrals?



i dunno lol...apparently so!!!!


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## BurtiElectric (Jan 11, 2011)

The estop that controls the gas panel (all loads in class 1 div 1) need to be cut including the neutrals when the estop is pushed. You can use individual breakers or a shunt trip switched neutral breaker to feed the gas panel and drop the whole panel that way


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## static09 (Feb 19, 2012)

BurtiElectric said:


> The estop that controls the gas panel (all loads in class 1 div 1) need to be cut including the neutrals when the estop is pushed. You can use individual breakers or a shunt trip switched neutral breaker to feed the gas panel and drop the whole panel that way


i see...ok come to think of it i do remember one job an inspector made me switch to a 4pole contactor on a generator....he wanted the neutral to be switched with the phases...long ago...vaguely...hmmmm


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## BurtiElectric (Jan 11, 2011)

static09 said:


> i dunno lol...apparently so!!!!


Maybe not in Canada :blink:


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## static09 (Feb 19, 2012)

BurtiElectric said:


> Maybe not in Canada :blink:


i couldnt tell ya...we never do them...cec is a mess lol


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## NoSparkSparky (Mar 5, 2012)

only time i ever run into switched neutrals is on knob and tube (or the occasional idiot handy man job)... knob and tube you just switched whatever required the least ammount of wire... if the neutral run was nearby, of course youd switch that, since it required the last ammount of wire, and there was no code saying otherwise.


also really fun things like carter sytem 3 ways!


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## spook (Oct 20, 2011)

My house has switched neutrals everywhere and is a royal pain,I'm slowly changing them over as rewire it. I also have a buddy who decided to change a light and it was a switched neutral and figured turn the switch off good to go. Turns out the little poke get got was enough to knock him off the ladder and broke his wrist.


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## RIVETER (Sep 26, 2009)

kbatku said:


> In knob & tube houses switching the neutral was standard practice. Don't ask me why - it made sense at the time.


Maybe they thought at the time that it kept the hot wire out of reach of the hands of people possibly working at the outlet.


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## Honestly (Feb 3, 2011)

Still no clue what the OP was about...


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## erics37 (May 7, 2009)

An overload relay on a motor starter often switches a neutral in 120V controls


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## RIVETER (Sep 26, 2009)

Honestly said:


> Still no clue what the OP was about...


I am assuming that you are serious . What the OP was talking about was routing the hot wire to a light fixture and taking the neutral wire down to the switch on the wall. The return of the switch to the light is at ground potential but completes the path to the light...illuminating it.


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## Honestly (Feb 3, 2011)

Ok. The 220 threw me. He must temporarily sent power from another circuit/ other leg- up the neutral while troubleshooting. Got it.


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## RIVETER (Sep 26, 2009)

Honestly said:


> Ok. The 220 threw me. He must temporarily sent power from another circuit/ other leg- up the neutral while troubleshooting. Got it.


It happend to me, as well. I was installing a switch on the wall for an existing lighting outlet in a very old house. I installed the switch beside an existing receptacle and picked up the "hot" there. It was a hot of the other phase and the light blew because I now had 220 on it.


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## hardworkingstiff (Jan 22, 2007)

RIVETER said:


> I am assuming that you are serious . What the OP was talking about was routing the hot wire to a light fixture and taking the neutral wire down to the switch on the wall. The return of the switch to the light is at ground potential but completes the path to the light...illuminating it.





Honestly said:


> Ok. The 220 threw me. He must temporarily sent power from another circuit/ other leg- up the neutral while troubleshooting. Got it.


I was thinking he did a panel change and installed 2-pole breakers in place of the switched neutral breakers (which would but the 240 on it).

It would be nice if he came back to tell us.

Oh, BTW, I always heard in Canada you were not to break the neutral for gas stations (don't know for sure, but that's what I was told years ago).


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## bgleason (Mar 3, 2012)

Back in the day, that was how they rolled. If you do any work on "early" wired houses, you see it a lot.


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## McClary’s Electrical (Feb 21, 2009)

Honestly said:


> Ok. The 220 threw me. He must temporarily sent power from another circuit/ other leg- up the neutral while troubleshooting. Got it.


 
It can easily happen on a service change. If the original service on the house was 120 volt, and the house is two stories, be very careful on the service change. You can end up with 240 on a light pretty easy.


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## electric ninja (Feb 29, 2012)

Sorry about the confusion, I felt the same way looking at it. It is for the jacking system on an oil rig. The way it was wired up was with 2 blacks going to a 2 pole 30 amp breaker. The load side of the breaker had a black and a white. I had now power on the rig, so I had no confirmation of the typical wiring. I checked continuity and had to assume it was a 220 volt circuit (2 pole breaker). I did see the wires split up and started to think ok this circuit is taking 120v of one leg to a desired location and 120v of the other leg to another location. Then I wasn't so sure about that because I didn't have a neutral. In the end, the way this all works is they hook up a hot and a neutral to a 2 pole breaker and when you turn the breaker off it opens the neutral. I don't see any benefit, and would never do this unless there is some sort of benefit to doing something this way. Thanks for the insight.:thumbup:


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## electric ninja (Feb 29, 2012)

Seems to be commonly used around hazardous areas, mainly for static.


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## brian john (Mar 11, 2007)

electric ninja said:


> Seems to be commonly used around hazardous areas, mainly for static.


 
Not because of static, but due to the possibility of arcing.


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## electric ninja (Feb 29, 2012)

Wouldn't the dissipitation of static caused by the opening of a neutral greatly reduce the chance of arcing?:thumbsup:


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## brian john (Mar 11, 2007)

electric ninja said:


> Wouldn't the dissipitation of static caused by the opening of a neutral greatly reduce the chance of arcing?:thumbsup:


 
Not is not static that is interrupting a load.


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## adamv7010 (Mar 21, 2011)

I live in a historic branded home and all my neutrals are switched...could rewire as original to maintain the historic brand. 

I still have an stab lok panel too...that **** needs to go


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