Bigger breaker for 2nd AC

[dfowler]

I recently had a second AC installed in the bedroom in my 2012 Sundance. Each AC has separate breakers. The living area AC breaker is 20/15. The second AC breaker is 15/15. On occasion the bedroom AC trips its breaker. Is it OK to replace the 15/15 breaker with a 20/20 one? I haven't been able to find a 20/15 breaker. Any advice appreciated!

 

[pegmikef]

I think it really depends on what gauge wire was used for the bedroom AC. Generally the rule is `15 amp is the max breaker for 14 gauge wire and 20 Amp is the max breaker for 12 gauge wire. If the breaker is too large for the wire, then the wire can heat up and start a fire without ever popping the breaker. JMHO.

 

[Jim.Allison]

Put two singles in, they have them at lowes, BUT, what is supposed to be on that line? Put in what is supposed to be on that line. If it does not work then chase the problem down and fix it. Do you have a clamp type multimeter?

 

[Gaffer]

Do not exceed a 15 amp breaker on 14 gauge wire. If the A/C is tripping, there is a problem. Try replacing the 15 amp breaker with another 15 because that is the easiest thing to do. If that fails there is either a problem with the A/C unit or the cable to the A/C unit. This assumes you have good power to the unit with no excessive voltage drop.

 

[danemayer]

If you installed a 15000 btu A/C instead of 13500 you may need 20 amps but need to check the wires first.

 

[Jim.Allison]

Might it still be wired for the larger unit as far as wire ga is concerned?

If you installed a 15000 btu A/C instead of 13500 you may need 20 amps but need to check the wires first.

 

[danemayer]

Might it still be wired for the larger unit as far as wire ga is concerned?

Two ways to proceed:

1) Actually check the wire gauge

2) Guess - or ask other people for their guesses

Get it wrong and maybe have a fire.

If it was me and it was a 15,000 btu A/C unit, I would check both ends of the wiring to make sure the wire is rated for 20 amps.

 

[bdb2047]

15/15,15/20,20/20 breakers are twin breakers they each connect to 1 lug on main buss they are used because size allows more breakers in same space. If not sure of wire size do not change to a higher amp. If you can see jacket of wire yellow jacket would indicate #12 wire white jacket #14. Most important if not familiar with working withe a/c wiring have someone who is check it.

 

[Jim.Allison]

If you have a breaker box manufactured by progressive in your Heartland, you can replace those double breakers with singles made for that purpose. But before you do, you must check that wire ga. Lest it glow red hot and burn the insulation off resulting in a hasty exit from said rig and light show at remote RV park.

15/15,15/20,20/20 breakers are twin breakers they each connect to 1 lug on main buss they are used because size allows more breakers in same space. If not sure of wire size do not change to a higher amp. If you can see jacket of wire yellow jacket would indicate #12 wire white jacket #14. Most important if not familiar with working withe a/c wiring have someone who is check it.

 

[hoefler]

You might ought to check your incoming voltage, if it is low, you would also trip breakers as your amp draw goes up due to low voltage.

 

[mslater]

first check ac unit for name plate fuse size… its not doing you any good to be worried about wire size first. … #12 is really only good for 16 amps (80% of 20 amps )than chose appropriate breaker.than check incoming voltage

 

[brianharrison]

Was the wiring and breaker installed at factory? If so a third option is to call Heartland with your VIN and ask if they can tell you if the bedroom vent came prewired with 14 or 12 gauge wiring.

Personally, I would check the print on the sheath, as the color is not a NEC requirement. That said a yellow sheath should indicate a 12 gauge, however an older (pre-2001) 12 gauge can be white, if an old roll of wire was used. Certified electricians "should" be able to visually distinguish wire gauge; know one?

The 20/15 breaker is available, here is one on Amazon - but as mentioned above - make sure the wire is 12 gauge for the new 20A. You will need to confirm the breaker is the correct style for your power distribution centre.

Note: all Dometic AC, even the 11,000 BTU, recommend a 12 gauge wire - as outlined on the spec sheet. (see page 4). I would go back to the installer (if not you) and take this up with them if they did install the new AC on 14 gauge/15 amp.

Brian