# Changing a 20 amp breaker to 30 amp in electrical panel



## iron_fist (Jan 15, 2021)

i post in the roofing forum so bear with me. I have a treadmill , a small refrigerator, and game consol that uses a particular breaker. Everytime i turn on the teadmill, the breaker trips. It never used to do that though. I called in a local guy and he suggested upgrading the breaker to 30 amp from 20 amp in the electrical panel we have in our garage , which he did and the problem seems fixed so far.
2 questions.
1) why would the breaker start tripping out of the blue? the problem does seem fixed though.
2) did he need to upgrade the wire to 10 guage in the control panel only or the whole line all the way to the outlet? Hiw can I tell if he at least upgraded the breaker wire to 10 guage?
I never asked, i assumed he did but i wasnt home, I was doing a roof install. He is now away til wednesday for memorial day weekend.


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## Pounder (Nov 28, 2020)

Put the 20 amp breaker back before you burn your house down. Put the electricians name on your list of "idiots I'll never use again". Breaker amperage and wire size have to be matched.

I've seen 40 amp breakers on 14gauge wire that had been in service for years without a problem, but that's because the circuit never hit the breaker capacity.


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## Seven-Delta-FortyOne (Mar 5, 2011)

That’s a complete hack job.

Take that 30A out NOW.

Why it started tripping I have no idea, but the solution is a dedicated 20A circuit for the treadmill.

There is no such thing as “breaker wire”. 😳There is a conductor from the breaker to the receptacles.

Those receptacles are not rated for 30A either.

Hire a real electrician please next time, before some a$$#ole kills you and your family 👍


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## griz (Nov 26, 2009)

Tripping out of the blue...

Breakers get old and may get tempermental.

You could have a problem with devices plugged into to curcuit causing an increase in needed amperage.

Change 20 to 30, not without rewiring.

Your fire ins paid up????


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## iron_fist (Jan 15, 2021)

His office is out til wednesday. If i pull the plugs and dont use anything for the next 4 days, will I be safe from a fire ?
also, what is the wire that should be 10 guage? Does that mean re wiring the whole wall?


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## Seven-Delta-FortyOne (Mar 5, 2011)

Just go flip the 30A breaker to off. 👍


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## avenge (Sep 25, 2008)

So you actually paid this "local guy"? I can't believe an actual electrician would do this.


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## Seven-Delta-FortyOne (Mar 5, 2011)

If he did that, he ain’t an electrician. 👍🤣


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## Seven-Delta-FortyOne (Mar 5, 2011)

iron_fist said:


> His office is out til wednesday. If i pull the plugs and dont use anything for the next 4 days, will I be safe from a fire ?
> also, what is the wire that should be 10 guage? Does that mean re wiring the whole wall?


Putting 10 gauge in won’t solve your problem, because then you would need 30A receptacles, and those are completely different and none of your stuff would plug in.

As I said, a dedicated circuit for your high amperage equipment is the solution. 👍


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## hdavis (Feb 14, 2012)

Treadmill motors can be anywhere from roughly 2.5 HP to 5 HP. It depends on the treadmill. There is electronic speed control on them, so a problem with the controller can be a real problem.

If it's just a weak breaker, a 20A new one will solve the issue. The sparky should have tried that, and if it still popped, it's a wiring or load issue. Pull the breaker so you can't energize the circuit. A 30A breaker on a 20A circuit is a no no.

Just my opinion.


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## iron_fist (Jan 15, 2021)

ok, his office just called me back; an elderly lady. she said he upgraded a 15 amp to 20 not 30..
i just checked the breaker and it says 20.. my bad..
do the same rules apply though?


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## Pounder (Nov 28, 2020)

iron_fist said:


> ok, his office just called me back; an elderly lady. she said he upgraded a 15 amp to 20 not 30..
> i just checked the breaker and it says 20.. my bad..
> do the same rules apply though?


Depends on the wiring. The safe bet is that the circuit was run with 14 gauge wire, and that gets a 15 amp breaker. It's possible that the the wiring is 12 gauge and the breaker was down graded, but I'd still guess that there was a reason for that.
The fellow is probably going to tell you that he "does it all the time without any issues", and that could well be true. But he's playing Russian roulette with the gun pointed at your head.


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## iron_fist (Jan 15, 2021)

Pounder said:


> Depends on the wiring. The safe bet is that the circuit was run with 14 gauge wire, and that gets a 15 amp breaker. It's possible that the the wiring is 12 gauge and the breaker was down graded, but I'd still guess that there was a reason for that.
> The fellow is probably going to tell you that he "does it all the time without any issues", and that could well be true. But he's playing Russian roulette with the gun pointed at your head.


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## iron_fist (Jan 15, 2021)

so going from 15 to 20 is just as dangerous as going from 20 to 30?
why dont builders just make all the breakers 20 amp?


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## Seven-Delta-FortyOne (Mar 5, 2011)

What pounder said. 👍


Unlikely that the wire gauge is suitable for a 20A.

Swapping breakers is just hack work.

The fact that it was only a 15A makes a lot more sense. That’s a little small for treadmills and other equipment.

Uou should still get another circuit installed for the treadmill. 👍


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## hdavis (Feb 14, 2012)

Money.


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## Seven-Delta-FortyOne (Mar 5, 2011)

iron_fist said:


> so going from 15 to 20 is just as dangerous as going from 20 to 30?
> why dont builders just make all the breakers 20 amp?


I find myself running very few if any 15A circuits.

There is absolutely nothing wrong with them though


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## hdavis (Feb 14, 2012)

X2. 15A barely handles a vacuum cleaner.


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## avenge (Sep 25, 2008)

Pounder said:


> The fellow is probably going to tell you that he "does it all the time without any issues", and that could well be true.


I've heard that so many times from hacks. Very unlikely that the original wiring is 12 gauge on a 15 amp breaker


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## Seven-Delta-FortyOne (Mar 5, 2011)

hdavis said:


> Money.


That, and 14 is so much easier to work with and fit into boxes.

I never run 15A receptacle circuits. I might use them for lighting only circuits though.


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## GDSCRemodels (May 20, 2021)

iron_fist said:


> That certainly looks beautifull. I love Southern CA as well along the coast but you have too much of that liberal nonsense.


The barge hole is in Northern California, you will have to pass 10 thousand trump flags to get here from the grapevine.

People think California is full of a bunch of gender neutral spineless zombies, but if you look at the political makeup in terms of geography we are no different than most other states that are blue merly because of 1 or 2 metropolises that control the state because there is 100 metros for every one country boy


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## 480sparky (Feb 1, 2009)

KennMacMoragh said:


> I was going to mention you ahead of time to avoid arguing. People have posted this same chart before and you disagree with it every time. That's why I said there are exceptions. But go ahead and do your thing, not sure if it will matter in this case.


It never will matter because charts like that get repeated so damned often no one believes the real answer, which is, "Depends".




GDSCRemodels said:


> I would certainly like to know the exceptions. I know its not that cut and dry, it all has to do with heat ratings/capacity in the end. The material the wire is made of, stranded or non stranded, NM or conduit. Underground. Is your conduit packed to the gills, that will certainly decrease your load limits.


Take a look at Table 210.3. That's a starting point.


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## KennMacMoragh (Sep 16, 2008)

480sparky said:


> It never will matter because charts like that get repeated so damned often no one believes the real answer, which is, "Depends".


Yes, saying it's generally true with exceptions is also a real answer. The point is in residential wiring those exceptions are rare. If you see a 14 gauge wire hooked up to a 20 amp circuit then chances are something is wrong. So it's important to know what that chart is.


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## GDSCRemodels (May 20, 2021)

Cerrowire Resources - Ampacity Charts







www.cerrowire.com





I have a 500' roll of 10g thhn that I will be using for my generator back feed. Its a 150' run from the receptacle to the service panel. At first I was worried the wire would not be sufficient to carry a 30 amp 220v load that distance, but according to this chart the 10 gauge wire is rated to 40 amps. Though my concern is the distance, so voltage drop would be the issue, not amperage. Would it be wise to upsize the wire for this distance, or is it not long enough to be a concern?


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## KennMacMoragh (Sep 16, 2008)

GDSCRemodels said:


> Cerrowire Resources - Ampacity Charts
> 
> 
> 
> ...


Without doing a calculation I’d say you’re o.k. It takes three 100’ extension cords, 12 gauge before you feel the voltage drop with a skill saw. 150’ with 10 gauge I think you’ll be fine.


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## Pounder (Nov 28, 2020)

480sparky said:


> It never will matter because charts like that get repeated so damned often no one believes the real answer, which is, "Depends".
> 
> 
> 
> ...


Regardless of the exceptions, in a residential setting the inspector is going to use the simple table.


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## Seven-Delta-FortyOne (Mar 5, 2011)

For anyone who is interested in the facts about this, the Code section is 240.4(D).

While the 15-20-30 rule for 14-12-10 gauge wires is correct in general, there are many situations, even in residential, where that is not the case.

Some examples are aluminum wire, taps, motor-control circuits, A/C units, refrigeration, fire pumps, etc. 

The NEC is one of the more complex Codes in use, and while rules of thumb can be handy, you must remember that they don’t apply in a great deal of situations.


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## 480sparky (Feb 1, 2009)

Pounder said:


> Regardless of the exceptions, in a residential setting the inspector is going to use the simple table.


That's not an inspector then. That's an expector.


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## Seven-Delta-FortyOne (Mar 5, 2011)

GDSCRemodels said:


> Cerrowire Resources - Ampacity Charts
> 
> 
> 
> ...


I did a VD calc, and it shows 7 volts dropped, for a total of 2.9%. This is acceptable.

Remember that the NEC does not require VD be below and amount, it merely suggests that it be below 3% for branch circuits, and 5% combined branch circuits and feeders.

If you are using THHN/THWN, that will have to be in conduit.


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## Pounder (Nov 28, 2020)

480sparky said:


> That's not an inspector then. That's an expector.


And as long as we're both expecting the same thing, I'm fine with it. I need the inspector to walk in, look over the work, say "great job", sign the card and leave. I have no desire to argue minutia or esoteric building codes with him.


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## 480sparky (Feb 1, 2009)

Pounder said:


> And as long as we're both expecting the same thing, I'm fine with it. I need the inspector to walk in, look over the work, say "great job", sign the card and leave. I have no desire to argue minutia or esoteric building codes with him.


You can have him. I'd rather have inspector who know WHY it needs to be OK'd.


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## GDSCRemodels (May 20, 2021)

Seven-Delta-FortyOne said:


> I did a VD calc, and it shows 7 volts dropped, for a total of 2.9%. This is acceptable.
> 
> Remember that the NEC does not require VD be below and amount, it merely suggests that it be below 3% for branch circuits, and 5% combined branch circuits and feeders.
> 
> If you are using THHN/THWN, that will have to be in conduit.


Obviously in conduit.
I about choked when I bought a 250' roll of 12/2 and a 250' roll of 12/3 romex the other day. $550 dollars


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## Leo G (May 12, 2005)

buck a foot


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## Seven-Delta-FortyOne (Mar 5, 2011)

My closest HD has it back down to $140. 👍

And they actually have it in stock.


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## GDSCRemodels (May 20, 2021)

Seven-Delta-FortyOne said:


> My closest HD has it back down to $140. 👍
> 
> And they actually have it in stock.


local big electrical companies keep them cleaned out. they buy it by the pallet. went there cuz it was close to the job, all they had was 100' rolls for 100 dollars, thought id get a better price at the supply house, at least they had what I needed


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## WAATAA (Jun 2, 2021)

iron_fist said:


> i post in the roofing forum so bear with me. I have a treadmill , a small refrigerator, and game consol that uses a particular breaker. Everytime i turn on the teadmill, the breaker trips. It never used to do that though. I called in a local guy and he suggested upgrading the breaker to 30 amp from 20 amp in the electrical panel we have in our garage , which he did and the problem seems fixed so far.
> 2 questions.
> 1) why would the breaker start tripping out of the blue? the problem does seem fixed though.
> 2) did he need to upgrade the wire to 10 guage in the control panel only or the whole line all the way to the outlet? Hiw can I tell if he at least upgraded the breaker wire to 10 guage?
> I never asked, i assumed he did but i wasnt home, I was doing a roof install.  He is now away til wednesday for memorial day weekend.


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## WAATAA (Jun 2, 2021)

iron_fist said:


> i post in the roofing forum so bear with me. I have a treadmill , a small refrigerator, and game consol that uses a particular breaker. Everytime i turn on the teadmill, the breaker trips. It never used to do that though. I called in a local guy and he suggested upgrading the breaker to 30 amp from 20 amp in the electrical panel we have in our garage , which he did and the problem seems fixed so far.
> 2 questions.
> 1) why would the breaker start tripping out of the blue? the problem does seem fixed though.
> 2) did he need to upgrade the wire to 10 guage in the control panel only or the whole line all the way to the outlet? Hiw can I tell if he at least upgraded the breaker wire to 10 guage?
> I never asked, i assumed he did but i wasnt home, I was doing a roof install. He is now away til wednesday for memorial day weekend.


Is the treadmill plugged into a GFCI outlet?


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## Bearpau (Jan 8, 2013)

A lot of treadmills require an isolated ground. 
find a good electrician
Turn off 30 amp breaker
Run a dedicated circuit to the treadmill.


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## WAATAA (Jun 2, 2021)

I say put the 20 amp breaker back in plug it into an outlet that’s not a GFCI, it should work fine.


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## avenge (Sep 25, 2008)

Bearpau said:


> A lot of treadmills require an isolated ground.
> find a good electrician
> Turn off 30 amp breaker
> Run a dedicated circuit to the treadmill.





WAATAA said:


> I say put the 20 amp breaker back in plug it into an outlet that’s not a GFCI, it should work fine.


Both of you should refrain from posting on this thread.


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