Forum Discussion

scooterd145's avatar
scooterd145
Explorer
Jun 11, 2018

Trying to find a suitable A/C load center replacement

Hi there, I have a QO Load Center that has gone bad. I am trying to locate a suitable replacement but of course mine is obsolete (QO4-7RM70TTS) and parts are no longer available. My main problem is space is limited of course and just heading down to my local HD or Lowes I come away with stuff that is way too big.

The DC stuff is working fine but I have no shore power and I eventually traced it inside the load center, the bus bar was cracked and has broken away from its mount. I discovered this while pulling the main circuit breaker thinking maybe it had gone bad

On my rig the power cord enters the load center directly into a main circuit breaker and then there are 3 additional circuit breakers that feed Air Conditioner - Microwave - Misc. The DC stuff is separate and like I mentioned is working fine.

The current breaker box is 10 x 7.5 x 3 I could go a little larger by doing some cutting of the opening but not a lot.

Is there a "standard" A/C load center I should look for? Should I look at doing away with this style and converting to some kind of combo AC/DC system?

I am fairly handy and build/fix my own stuff but my expertise is more along the line of motorcycles. I am pretty good with watching a youtube or three and figuring out stuff so let me know what you think.

P.S it is not for the Coachman rig in my profile
Scott
  • ScottG's avatar
    ScottG
    Nomad
    Jun 12, 2018
    You may be able to replace the bus bar alone. Places like Home Depot sell them.
    Or you could go to Bestconverter.com for a whole new load center.
  • theoldwizard1's avatar
    theoldwizard1
    Explorer II
    Jun 12, 2018
    What is your "feed" ? 50A (240V, 4 wire) or 30A (120V, 3 wire) ? Flush mount or surface mount ?
  • theoldwizard1's avatar
    theoldwizard1
    Explorer II
    Jun 12, 2018
    Doing some googling, I think the best you are going to do is a 2 space, 4 circuit load center, like this Homeline Homeline 2 space 4 circuit load center



    It should accept tandem breaker. It is available at Home Depot, Lowes (both will likely have to order it) or Amazon. You will likely have to order a ground bar.

    Any of the 4 space load centers are too big.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jun 12, 2018
    Check out Progressive Dynamics (you will have to google 'em)

    THey make some nice and SMALL load centers. (I call them distribution panels) as well as intergrated load center/Converters. The load centers are in shapes you do not often see at Lowe's or Home Depot. (Like mine is one breaker high by several breakers wide 50 amp) and the converters.... I've been trying for over a deacade to find one better... Without success. (My of saying best made).
  • scooterd145's avatar
    scooterd145
    Explorer
    Jun 13, 2018
    Thank you folks for taking the time to answer my question.

    My rig is 30Amp 120V 3 wire.

    I tried getting a replacement buss bar but this one was obsolete and not available

    I ended up going with one from Home Depot that was almost as small and that I could modify the hole it fits in and still close the cupboard door that is in front of it. I was assured that even though this one is main lug (as opposed to main breaker) that the main breaker from the rig cord will back feed other breakers on that side of the buss bar. If he is right I am in business.

    https://www.homedepot.com/p/Square-D-Homeline-100-Amp-6-Space-12-Circuit-Indoor-Surface-Mount-Main-Lug-Load-Center-with-Cover-HOM612L100SCP/100190554

    It was certainly cheap enough and in stock, even with new breakers I am under $60. With any luck I will have it back together this weekend.
    I'll let you know if this solves my problem!

    Thanks
    Scott
  • DrewE's avatar
    DrewE
    Explorer II
    Jun 14, 2018
    scooterd145 wrote:
    Thank you folks for taking the time to answer my question.

    My rig is 30Amp 120V 3 wire.

    I tried getting a replacement buss bar but this one was obsolete and not available

    I ended up going with one from Home Depot that was almost as small and that I could modify the hole it fits in and still close the cupboard door that is in front of it. I was assured that even though this one is main lug (as opposed to main breaker) that the main breaker from the rig cord will back feed other breakers on that side of the buss bar. If he is right I am in business.

    https://www.homedepot.com/p/Square-D-Homeline-100-Amp-6-Space-12-Circuit-Indoor-Surface-Mount-Main-Lug-Load-Center-with-Cover-HOM612L100SCP/100190554

    It was certainly cheap enough and in stock, even with new breakers I am under $60. With any luck I will have it back together this weekend.
    I'll let you know if this solves my problem!

    Thanks
    Scott


    That should work, with a couple of caveats. First, you'll need (and maybe already have) the ground bus bar that is sold separately, as an RV needs to have the neutral and ground busses isolated from each other.

    Second, it's a 120/240V load center, so you'll either have to skip every other breaker position (using three of the six) or else connect a jumper wire between the two main lugs of sufficient size to carry the full service current (i.e. 10 gauge or heavier). In either case, the main breaker needs to be a single pole breaker; a double pole main breaker should not be used in this application, as it's a 120V circuit and not a 120/240V circuit. I don't know that jumpering the main lugs would technically be acceptable per the NEC, but if done properly it's not unsafe.
  • scooterd145's avatar
    scooterd145
    Explorer
    Jun 15, 2018
    Well I did it and it worked! I did add a ground bar and used every other circuit (was easy/obv) to follow on the bus bar which ones. In my case I onlt needed the 3 circuits so it worked out FANTASTIC. Hope this helps someone else out some day

    Scott
  • Dutch_12078's avatar
    Dutch_12078
    Explorer II
    Jun 15, 2018
    Make sure the neutral bus is isolated from the ground bus per NEC requirements.

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