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Changing breaker switch.

Yahoo Message Number: 98676
I need an additional outlet in my coach.  There is a circuit that has a 20 amp breaker, the wire is 12 gage.  Can I  change the 20 amp breaker to 30 amp?    Then tap into the existing circuit?  The tota approxamatel length of the 12 gage will be  35 ft.  The measured amp draw is 24 amps.

Bo & Kathy Lee

2000 Magna #5896 40 FT

2006 Jeep Wrangler Unlimited
Rubicon

Re: Changing breaker switch.

Reply #1 –
Yahoo Message Number: 98679
Not allowed to land a #12 conductor on a 30 amp breaker, there are exceptions used in motor control applications. Sounds like your new load you are adding is kinda high (?) I know its a job but probably need a home run to the panel if at all possible. If the panel is full piggy back breakers are available from the big box stores.

If your adding a small heater those things are terrible on branch circuits. When its cold we do a service call a week on a cooked receptacle or breaker (sometimes both).

Good luck

Nate Blackwell

Electrical contractor who cruises in an old 1998 Allure on his time off Indianapolis

Re: Changing breaker switch.

Reply #2 –
Yahoo Message Number: 98680
This would not be legal according to the electrical code nor really safe.  #12 wire is only rated for 20 amps.

Is the circuit currently drawing 24 amps or is that what the final load would be?  That is too much for #12 wire and is right at the limit for a 30 amp breaker and #10 wire. If you changed to a 30 amp breaker you should also change the wiring to be #10 wire.  In actuality you shouldn't load a circuit more than 80% - so 16 amps on a 20 amp breaker.

The job of the breaker is to protect anything after or downstream from a load greater than the breaker size.  So all the wiring, outlets and anything you use on a 20 amp breaker should be rated for at least 20 amps and not exceed 20 amps.  #12 wire is only rated for 20 amps, so it is OK.

Hope this helps 
Dan

2006 Allure 430 with tag
#31344

Re: Changing breaker switch.

Reply #3 –
Yahoo Message Number: 98681
Think of it this way the breaker should ALWAYS be the weakest  link, I.e. the lowest rated component. If you are truly needing to draw 24 amps  I would expect it to be a dedicated circuit.

Ray

They say wine improves  with age! As I enter my golden years, I say age improves with wine!  The Born  Loser

Re: Changing breaker switch.

Reply #4 –
Yahoo Message Number: 98684
Thanks Nate.

I all ready have a spare bay breaker but can't find the wire feed in the basement. Anyone know where it might be. I searched all the basement sealings for outlet plates. Keven Waite said it should be in the 1st or second bay from front but nothing I can find. There  is a outlet in the sealings in the third bay but that is on the refig. breaker.

Bo & Kathy Lee

2000 Magna #5896 40 FT

2006 Jeep Wrangler Unlimited
Rubicon

Re: Changing breaker switch.

Reply #5 –
Yahoo Message Number: 98686
Hi, we have a 2000 magna 36 -5886 and the spare 12 wire was in the bay with the fuse panel,i ran the spare ckt up to heater i installed under the table. charles

Re: Changing breaker switch.

Reply #6 –
Yahoo Message Number: 98692
No. 12 gage wire will not support a 30amp load. Worst case in the event of a wire overload, the insulate on the wire could catch fire and burn your coach to the ground. You can change out the standard 20 amp breaker for a split 20 amp breaker. It is physically the same size as you standard breaker but it has two independent switches on it to feed two separate circuits.
Britt

2004 Intrigue Ovation 525
11836

Re: Changing breaker switch.

Reply #7 –
Yahoo Message Number: 98694
#12 awg is only acceptable for 20 amps or less and I wouldn't push the envelop even though the insulations is rated at a much higher as I remember.  You need  #10 awg.  TWI 2004 Intrigue 11731