# Stepping down 220v to 110v, what happens if transformer breaks



## Wire Tags (May 11, 2016)

If I step down 220v to 110v using a step down transformer, then hook up the 110v to a breaker panel, if the transformer were to break down, could the voltage at my breaker panel be 220v?

and if the voltage going into my breake panel is 220v, then would the increase in voltage push more current through my loads that is connected to the breaker panel?

If all the above is true, is there a way that I can protect my loads from frying in the event that my transformer breaks down?


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## papaotis (Jun 8, 2013)

as much as id like to have fun with this, i believe there are much more qualified guys here that take care of it:jester:


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## Voltron (Sep 14, 2012)

Maybe you should consider a 240v to 220v step down transformer. It would run your breaker panel with less stress on the electrons, therefore avoiding a catastrophic meltdown on the flux capacitor.


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## backstay (Feb 3, 2011)

Flux capacitors are so 80's tech. We use voltage stabilizing reactors now.


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## macmikeman (Jan 23, 2007)

backstay said:


> Flux capacitors are so 80's tech. We use voltage stabilizing reactors now.


That's not near as cool as sending it thru a roll of 14-2 romex first.


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## circuitman1 (Mar 14, 2013)

if it's a autotransformer then there could be a big problem. but if it's a two coil tranny not much happens usually. they generally burn out. but i have seen a two winding lose the neutrul , & 240 was sent across things. depends also what loads are in series.usually with awful results.


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## backstay (Feb 3, 2011)

macmikeman said:


> That's not near as cool as sending it thru a roll of 14-2 romex first.


Or 1/2 EMT


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## telsa (May 22, 2015)

Wire Tags said:


> If I step down 220v to 110v using a step down transformer, then hook up the 110v to a breaker panel, if the transformer were to break down, could the voltage at my breaker panel be 220v?
> *
> [ Nope. ]*
> 
> ...


The usual and customary solution to this is OCPD upon the secondary conductors.

See the NEC. 

BTW, your concerns were addressed -- back when Tesla and Westinghouse were playing their games -- 140 years ago.

:laughing::whistling2::blink:


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## Wire Tags (May 11, 2016)

telsa said:


> The usual and customary solution to this is OCPD upon the secondary conductors.
> 
> See the NEC.
> 
> ...


Iam concerned that the over current protection device, can't protect my loads because the increase in current is not large enough to trip the OCPD, but is large enough to fry my load, and I don't think my loads have any built in OCPD.


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## Southeast Power (Jan 18, 2009)

Wire Tags said:


> Iam concerned that the over current protection device, can't protect my loads because the increase in current is not large enough to trip the OCPD, but is large enough to fry my load, and I don't think my loads have any built in OCPD.


Only two things can really happen.
One. The coil develops a short, the current will increase beyond the primary OCP rating and will open.
Two. The coil will open and no voltage will be available on the secondary.

Look around you. There could be dozens of transformers all around you operating on this principal.


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## backstay (Feb 3, 2011)

jrannis said:


> Only two things can really happen.
> One. The coil develops a short, the current will increase beyond the primary OCP rating and will open.
> Two. The coil will open and no voltage will be available on the secondary.
> 
> Look around you. There could be dozens of transformers all around you operating on this principal.


You're a real joy killer, you know.


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## papaotis (Jun 8, 2013)

i knew you guys would come through! welcome back cletis!:thumbsup:


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## nom-board (Jun 3, 2016)

circuitman1 said:


> if it's a autotransformer then there could be a big problem. but if it's a two coil tranny not much happens usually. they generally burn out. but i have seen a two winding lose the neutral , & 240 was sent across things. depends also what loads are in series.usually with awful results.


 That it a break in the neutral or between two different unbonded transformers from earth secondaries present all types of problems the same as floating grounds. The exotic voltages are really amazing. Industrial normally uses 480 and a split phase 240/ 120 volt transformer. commercial 208 3phase in wye with a 120 volt on each leg. 3 phase Motors such as Dayton are 208-230 or 460 because the voltage drop is already taken into account. so if we are talking about 110, 115 or 120volts we are really talking about the same thing. But a split phase motor in that voltage range of 220 to 240 would produce a lot of noise a danger of arch faults. In Brazil it is common in some parts to use 127v single and 220 3 phase in a wye with and ungrounded neutral. The electrical noise can cause sensitive electronic equipment to go out, each phase will be 220 volts to ground. the neutral should be cold. While all grounds need to be the same it is never a good idea to have difference in grounds greater then 25 ohms as required by the NEC 250.56 the NFPA and IEEE have recommended 5 ohms or less to earth.While some location call for GFCI recent changes call for arch fault in bedrooms. While some homes maybe grandfather in industrial and commercial location will be required by OSHA to be updated.....


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## nom-board (Jun 3, 2016)

*noise*



circuitman1 said:


> if it's a autotransformer then there could be a big problem. but if it's a two coil tranny not much happens usually. they generally burn out. but i have seen a two winding lose the neutral , & 240 was sent across things. depends also what loads are in series.usually with awful results.


 That it a break in the neutral or between two different unbonded transformers from earth secondaries present all types of problems the same as floating grounds. The exotic voltages are really amazing. Industrial normally uses 480 and a split phase 240/ 120 volt transformer. commercial 208 3phase in wye with a 120 volt on each leg. 3 phase Motors such as Dayton are 208-230 or 460 because the voltage drop is already taken into account. so if we are talking about 110, 115 or 120volts we are really talking about the same thing. But a split phase motor in that voltage range of 220 to 240 would produce a lot of noise a danger of arch faults. In Brazil it is common in some parts to use 127v single and 220 3 phase in a wye with and ungrounded neutral. The electrical noise can cause sensitive electronic equipment to go out, each phase will be 220 volts to ground. the neutral should be cold. While all grounds need to be the same it is never a good idea to have difference in grounds greater then 25 ohms as required by the NEC 250.56 the NFPA and IEEE have recommended 5 ohms or less to earth.While some location call for GFCI recent changes call for arch fault in bedrooms. While some homes maybe grandfather in industrial and commercial location will be required by OSHA to be updated.....


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## nom-board (Jun 3, 2016)

*noise*



circuitman1 said:


> if it's a autotransformer then there could be a big problem. but if it's a two coil tranny not much happens usually. they generally burn out. but i have seen a two winding lose the neutral , & 240 was sent across things. depends also what loads are in series.usually with awful results.


 That it a break in the neutral or between two different unbonded transformers from earth secondaries present all types of problems the same as floating grounds. The exotic voltages are really amazing. Industrial normally uses 480 and a split phase 240/ 120 volt transformer. commercial 208 3phase in wye with a 120 volt on each leg. 3 phase Motors such as Dayton are 208-230 or 460 because the voltage drop is already taken into account. so if we are talking about 110, 115 or 120volts we are really talking about the same thing. But a split phase motor in that voltage range of 220 to 240 would produce a lot of noise a danger of arch faults. In Brazil it is common in some parts to use 127v single and 220 3 phase in a wye with and ungrounded neutral. The electrical noise can cause sensitive electronic equipment to go out, each phase will be 220 volts to ground. the neutral should be cold. While all grounds need to be the same it is never a good idea to have difference in grounds greater then 25 ohms as required by the NEC 250.56 the NFPA and IEEE have recommended 5 ohms or less to earth.While some location call for GFCI recent changes call for arch fault in bedrooms. While some homes maybe grandfather in industrial and commercial location will be required by OSHA to be updated.....


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## nom-board (Jun 3, 2016)

Wire Tags said:


> If I step down 220v to 110v using a step down transformer, then hook up the 110v to a breaker panel, if the transformer were to break down, could the voltage at my breaker panel be 220v?
> 
> and if the voltage going into my breake panel is 220v, then would the increase in voltage push more current through my loads that is connected to the breaker panel?
> 
> If all the above is true, is there a way that I can protect my loads from frying in the event that my transformer breaks down?


 ??? Where are you getting the 220 from an inverter? If you are on the grid you should already have split phase or are you trying to use one leg of a 480 volt/ 460 volt wye or delta 3 phase supply. Each leg would be 277v to 267v on a wye transformer. How sensitive is all of the electronics on the circuit? Would an arch fault breaker help?


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## Wired.hassle (Jun 6, 2016)

telsa said:


> The usual and customary solution to this is OCPD upon the secondary conductors.
> 
> See the NEC.
> 
> ...


Is this a DC transformer? Those options would be great if so.
However , IF its AC the OP will need two panels with GFCI hooked up at either end and probably 6 or 8 ground rods to bond his Floating Neutral. Also recomend he place 2 transformers in series so he can alternate the frequency. 
Oh and 18\3 should be fine as long as he runs two metal conduits one for load and one for those 6 grounds. :thumbsup:


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## nom-board (Jun 3, 2016)

*Yes*



Wire Tags said:


> If I step down 220v to 110v using a step down transformer, then hook up the 110v to a breaker panel, if the transformer were to break down, could the voltage at my breaker panel be 220v?
> 
> and if the voltage going into my breake panel is 220v, then would the increase in voltage push more current through my loads that is connected to the breaker panel?
> 
> If all the above is true, is there a way that I can protect my loads from frying in the event that my transformer breaks down?


 You can use Phase tech an ac to ac inverter try www.phasetechnoloogies.com. for smaller sizes other brands will work too.:thumbsup:


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## B-Nabs (Jun 4, 2014)

I'm beginning to have difficulty differentiating between dumb, troll, and bat-sh!t crazy in this thread.


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## nom-board (Jun 3, 2016)

*not enough information*



B-Nabs said:


> I'm beginning to have difficulty differentiating between dumb, troll, and bat-sh!t crazy in this thread.


 Well , do we have enough information on where he is getting his 220volts from, a generator? Or do we know what kind of equipment he is trying to protect? Information as to location, grounding, primaries supply aren't enough to address the issue. of things that could go wrong. In this case size matters, and I could hang my hat on that, so I guess I will until more information is given.


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## nom-board (Jun 3, 2016)

*we need more information?*



Wired.hassle said:


> Is this a DC transformer? Those options would be great if so.
> However , IF its AC the OP will need two panels with GFCI hooked up at either end and probably 6 or 8 ground rods to bond his Floating Neutral. Also recomend he place 2 transformers in series so he can alternate the frequency.
> Oh and 18\3 should be fine as long as he runs two metal conduits one for load and one for those 6 grounds. :thumbsup:


source of primary? what are we trying to protect?


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## nom-board (Jun 3, 2016)

*toast*



backstay said:


> Flux capacitors are so 80's tech. We use voltage stabilizing reactors now.


 I don't know the location, where he just has 220v. It could be a rural cabin with a generator and he might want to plug in his toaster. Will he get burnt toast?


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## Wired.hassle (Jun 6, 2016)

nom-board said:


> source of primary? what are we trying to protect?


A gun safe I think.


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## nom-board (Jun 3, 2016)

Wired.hassle said:


> Is this a DC transformer? Those options would be great if so.
> However , IF its AC the OP will need two panels with GFCI hooked up at either end and probably 6 or 8 ground rods to bond his Floating Neutral. Also recomend he place 2 transformers in series so he can alternate the frequency.
> Oh and 18\3 should be fine as long as he runs two metal conduits one for load and one for those 6 grounds. :thumbsup:


 A ac to ac inverter is really an ac to dc to dc to ac and is transformer less. Maybe a fast blow fuse would help over a slow blow.


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## nom-board (Jun 3, 2016)

*what is the secret?*



Wired.hassle said:


> A gun safe I think.


Now Now, it could just be a remote location where he wants to grow some pot and he has only 110volt grow lights, and he keeps his gun under the pillow. We really won't know unless he tells us.


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## Anathera (Feb 16, 2016)

I think you scared him off


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## nom-board (Jun 3, 2016)

*something going on*



Anathera said:


> I think you scared him off


 Well it just is reasonable to assume that it is somewhere off the grid and he wants to slip in under the wire. If he is up to growing pot by not helping he may get a buzz and get fried. But if he grows a good crop of pot he is still likely to use it to get a buzz and get Fried! especially on Fridays with the exception of Wednesdays where he will get blown away. All we can do is guess?:icon_confused:


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## nom-board (Jun 3, 2016)

*why it is inportant to know the types of loads*



Wire Tags said:


> If I step down 220v to 110v using a step down transformer, then hook up the 110v to a breaker panel, if the transformer were to break down, could the voltage at my breaker panel be 220v?
> 
> and if the voltage going into my breake panel is 220v, then would the increase in voltage push more current through my loads that is connected to the breaker panel?
> 
> If all the above is true, is there a way that I can protect my loads from frying in the event that my transformer breaks down?


 With surge currents being 3.5 times the locked rotor even a 2kva transformer would break down with a 1 hp motor. Voltage to ground could be higher then you might think if a break to the neutral to earth occurs.


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