help with AC power

Discussion in 'General RVing' started by kefros, Jun 7, 2005.

  1. kefros

    kefros New Member

    We are new to RVing. We have a class C motor home. All spring we have been plugged in to our home or the home of people we have visited and ran our AC as needed - no problems. Now this weekend we just came home from traveling and plugged in - we kept blowing the circuit on our home while plugged in. Also one night at a campground - the AC went off in the middle of a very hot night. But it appears to be working fine - it seems to be assoiciated with the power source. We are supposed to go visit in laws in Pheonix in July - we need AC as mil's house is way too small for us to stay with her.

    So is the house power sufficient to power the AC?
    Thanks :question:
     
  2. Poppa

    Poppa Member

    help with AC power

    When plugging into shore power make sure that you are plugged into one with a minimum of 20 amps for starters and do not run a lot of other electric appliances. The number one thing to remember is that when you use and extension cord for you motor home it needs to be 12-3 with a ground or better and with 12-3 it shouldn't be more than 50 feet.

    Basically what happens is the cord starts getting warm and it starts having more resistance which makes it get warmer then more resistance and during this time the voltage drops so the unit draws more amperage until finally the 20 amp breaker goes poof.
     
  3. jkill2001

    jkill2001 New Member

    help with AC power

    normally when ur connected thru 20 amp ur not supposed to run your a/c at all can harm the motors and all the small gizmo's in the a/c unit. but you can run basic electricity just keep an eye of what u use
     
  4. Krazeehorse

    Krazeehorse New Member

    help with AC power

    Another thing that can cause a problem is the line voltage. If a heat wave is on and everyone in the neighborhood is running their AC then the line voltage may be a little low. This raises the amperage and that may cause your breaker to trip or a thermal limit control to shut the unit down.
     
  5. kefros

    kefros New Member

    help with AC power

    :evil: So I guess we'll have to use the generator to load up in this hot and humid TN weather. thanks for the explanations and the help.

    So one more ? - is 'shore power' from my house 20 amp or 15 amp - I thought houses were 15 amp. And, couln't I plug into my dryer outlet if I wanted to?

    Thank you so much for all the help.
    I've wanted an RV for so many years and now we have one and oh man it is overwhelming at times trying to learn all the stuff.
    Kally
     
  6. kefros

    kefros New Member

    help with AC power

    Poppa - I always thought it would be so cool to ride a Harley around the country - what a way to travel.
    Kally
     
  7. Kirk

    Kirk Senior Member

    help with AC power

    The most common outlets in a house are of the 15A variety. Those are the stardard outlets that you see everywhere. And the circuit breaker that limits it to 15A does that for the total of all loads connected to that circuit. Most likely the circuit you were using had no other loads when you first used it, then had some extra when the breaker opened. The other thing that will effect that problem is the outside temperature. As the temperature increases, the power required to run the a/c unit also increases so on a hot day it will draw more current.

    A 20A outlet normally will have the left pin shaped like a lazy T, rather thah the slot you usually see. Very few homes have any 20A outlets unless installed for a specific load. And those most often will have only one outlet installe on the circuit.

    Your dryer outlet is not the proper voltage for the RV. There are two common types of dryer outlet. If it is a three pin outlet, it is a 30A, 240V outlet and the 30A plug of an RV will not plug in due to different pin configuration. That is done to protect you from cooking all of the electrical equipment in the RV by supplying twice the normal voltage. The other type of dryer outlet is a four pin and frequently they are the same as the one used for 50A service to an RV. The difference is that the tree pin has two hot leads that are 180 degrees out of phase and so they add together to make 240V. With the four pin there are two hot leads and also a neutral lead that allows you to connect the load between one hot and neutral, thus supplying 120V to each leg of the circuit. Those are called 240/120V outlets because the voltage to the load is determined by the way that the load is connected. There is an adaptor to connect your 30A RV cord to the four pin 240/120V plug safely. In the case of all outlets, the round pin is the ground lead, provided there for safety.
     
  8. hertig

    hertig Senior Member

    help with AC power

    If you are running from a (15 Amp) house outlet, make sure you only use 1 high draw appliance at a time, ie just AC or microwave or electric hot water heater or electric heater or hair dryer. Also, make sure nothing much is plugged into the same circuit in the house.
     
  9. kefros

    kefros New Member

    help with AC power

    Thanks so much for the information. I know this is a late responce - had internet problems.
    Kally
     

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