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scrapnread's avatar
scrapnread
Explorer
Jun 14, 2014

Generator question

We bought a 2014 Forest River Salem 27RKSS. It is 33 feet long and has one slideout. The air conditioner is on a 30 amp breaker, (I think). How do we figure out the formula for a generator? Would a 4000 watt one work? We are headed to the Grand Canyon area next weekend. and would appreciate the A/C working.. Any help would be appreciated. Thanks.

10 Replies

  • Before your trip, check on the approved generator hours for the campgrounds you'll be visiting.

    At the North Rim you're at about 8,000 elevation and aren't likely to need AC (I was there a week ago). The TT got to about 80 inside mid-day, but cooled quickly as soon as the sun dropped below tree level.

    At the South Rim you'll be lower and may benefit from A/C if your are OK to run a generator during the hours you think you'll be at the campground. Hopefully you're maximizing your time away from camp and enjoying the sights!
  • The simpler answer is: a 30 amp service x 120 volts = 3600 watts. I take this to mean that if all loads are running on a native 30 amp service, combined they will not be more than 3600 watts; or, with a 30 amp supply (which is the rated max of your converter)the max load will be 3600 watts and no more. Additional supply requirements cannot be fed through the native 30 amp system without stuff tripping or starting to overheat and catch fire.
  • Check out northern tools. I bought two of their 2000w quiet generators for $1200, when connected in parallel (they came with the cords Honda and Yamaha charge you another $100 for) they run everything in my trailer. When I don't need ac I can use just one of them. They are quiet, fuel efficient and 49pounds each. I camp without hook ups,,I have run those things for 5 days straight with no problem.
  • GENERATORS:

    If you simply want to charge the batteries a 1000w will do...

    If you want to run everything in the TT, EXCLUDING THE AIR, a 2000w will do...

    If you want to run the air AND NOTHING ELSE a 3000w will do...

    If you want to run the air with a lpower to spare a 4000w+ will do...

    I recommend either getting a Honda or Yamaha for a portable generator...

    For a built in generator like we have an Onan is a good way to go...
  • scrapnread wrote:
    So now my husband wants me to ask if there is a formula for figuring out the electric load/generator issue? Not sure if this makes sense but thanks again.
    If you want to figure out the amount of power the AC draws and compare it to how much power the generator is capable of, you'll need to look at the specifications (or rating plate attached) of the model you have. It will be something like 10 amps continuous and a LRD (locked rotor draw) of 15 amps, for example. The amps can be converted to watts by multiplying by 120. Using the above example values, that would be 1800W to overcome the LRD value for the duration of that load. The AC would then need 1200W to run.

    The generators differ in how much instantaneous load and how long that can be handled. Most gen sets are rated fairly close to their actual continuous output, I've found.
  • Red (Honda) + Blue (Yamaha)= Quiet. You could also substitute $ for quiet.
    Dave
  • So now my husband wants me to ask if there is a formula for figuring out the electric load/generator issue? Not sure if this makes sense but thanks again.
  • Have a 4000W gen....runs our 15K btu A/C, microwave, TV, converter etc.
  • Yes 4000 watts is 33 amps. We have a 4kw on our 30 amp toy hauler no problems with power.