A/C Unit wouldn't turn on but everything else worked with 30 Amp hookup.

[FatDaddy]

My travel trailer is only 23 feet long and is designed for a 30 Amp hookup.  The last time I went camping tough, the A/C wouldn't turn on. Everything else worked with 30 Amp hookup but no A/C. Luckily there was a 50 Amp switch, so I switched to the 50 Amp connection and the A/C fired right up. Has this happened to anyone else? Do I need to reserve only 50 Amp sites in the future?  They are more expensive, so that would be disappointing, and I can't imaging that all of those larger RVs are going without A/C in those 30 Amp sites. I've only been RVing for 2 years, so I'm still a little new at this.  Thanks in advance for any info you can provide!

 

[donn]

Let me get this straight.
Your TT is 30A.  Yet you say you have a 50A switch?  Never heard of anything like that.  If your talking about the breakers on the pedistal thats a different thing.  On 30A if your trying to run the AC, refer, and water heater all on 30A power, it aint going to happen.  Switching the water heater and refer to gas, then you can run the AC.
Depending on how things are wired on the pedistal its entirely possible the 30A outlet is powered from the 50A breaker,  so yes its possible in that instance thwt you would need the 50A breaker on to feed power to the 30A breaker.  Its not right, but how knows how some cowboy wired the box.

 

[Rene T]

The next time you go camping, plug into the 30 Amp outlet. Then shut everything off except for the AC. See if it works. You may find that some of the 30 Amp outlets are just worn out because of use. I believe they get more use than the 50 Amp outlets.

 

[John From Detroit]

"Luckely there was a 50 amp switch".. This explains it

You have an Intetec Energy Management System.  (not to be confused with Progressive Industries products of the same name which are completely different)

The intelletec system is designed to keep you BELOW 30 amps when on 30 amps. of course you can override it.  It does this by disabling selectred systems. A/C's being at the top of the list. water heater is next as I recall.  (If you had the water heater on depending on the way the EMS was connected it would disable the air conditioners. or one of 'em in any case if you are on 30 amps.

If you are on 50 amps it goes to "Sleep" and lets everything work

There may be be a "Front/Rear/Both switch somewhere (or Front/both/rear) as well and flipping that will turn on the OTHER A/C.

 

[Back2PA]

A 23 foot bumper pull with 50 amp service?    I'm guessing not

 

[AStravelers]

The way these energy management systems detect if you are on 50amp service or 30 amp service is:  If it sees 2 hot legs it assumes 50amp.  If it sees only 1 hot leg it assumes 30 amp.  HOWEVER it really doesn't KNOW or can detect the actual nnumber of amps available.  You can plug into a 15amp outlet and the energy manager will assume it is 30amp service.  There usually is a button you can press to tell it you are on 20amp service and maybe be able to tell it you are on 15amp service.

 

[BruceinFL]

I have found that in a lot of cases the old 30 amp circuits were worn out or heavily loaded so I always use a 50/30 dogbone adapter and hookup to the 50 amp circuit with my 30 amp RV. Most of the cg s now have both and don't charge extra for hooking to 50 amp. In the case of only 30 amp available, changing to another site often helped getting more available amps from the circuit.

 

[lynnmor]

Apparently you had a poor connection in the 30 amp outlet.  Look at your plug blades to see if there is any heat discoloration or evidence of arcing.  Keep your blades shiny with fine sandpaper or steel wool.  Always turn off the pedestal breaker before plugging in or out.  Plug in and out a number of times before use to wipe the contact area, the last guy yanked the plug and caused burn marks.  If the outlet has a loose fit, ask for it to be repaired or another campsite.  It is a good idea to either use the 50 amp connection with an adapter or use a sacrificial 30 male to 30 female dogbone adapter.

 

[cavie]

Please explain what the 50 amp switch is. 

 

[maddog348]

PLEASE 

 

[Old_Crow]

Read it again.  He says the TT is designed for 30amps. 
Sounds like he unplugged from the 30A, installed a dogbone, plugged into the 50A plug and everything worked.  Classic bad outlet.
I'm saying the 50A switch he refers to is the breaker on the power box.

 

[Back2PA]

Read it again.  He says the TT is designed for 30amps. 
Sounds like he unplugged from the 30A, installed a dogbone, plugged into the 50A plug and everything worked.  Classic bad outlet.

This brings up a related question to which I think I know the answer but want to confirm: in the 50 to 30 dogbones are L1 and L2 simply wired together?

 

[Old_Crow]

Not sure, but I think they are wired to one leg or the other.  I have seen people post about getting one of each to make a "Y" adapter of some sort.  Didn't pay that much attention as my coach is a 30A rig.

 

[Back2PA]

Not sure, but I think they are wired to one leg or the other. 

That's what I thought at first but if that was the case one branch in the RV would be dead, leading me to think they are wired together  ???

 

[Alfa38User]

On the output side of the adapter (the side towards the camper), the campers two legs are bridged together so both sides (L1 and L2) of the camper panel are powered. On the input side (pedestal side) you are simply plugged into a 30 amp outlet. You are, of course,  limited to 30 amps by the pedestal breaker

 

[Back2PA]

On the output side of the adapter (the side towards the camper), the campers two legs are bridged together so both sides (L1 and L2) of the camper panel are powered. On the input side (pedestal side) you are simply plugged into a 30 amp outlet. You are, of course,  limited to 30 amps by the pedestal breaker

Ok thanks

 

[ChasA]

In the case of a 30 amp camper hooked to a dogbone adapter which plugs into 50 amp pedestal only one hot leg from 50 A is used. If L1and L2 were wired together that would immediately blow the breaker.

 

[Alfa38User]

withdrawn comment due to my misinterpretation of of the previous comment.

 

[cavie]

This brings up a related question to which I think I know the answer but want to confirm: in the 50 to 30 dogbones are L1 and L2 simply wired together?

The dog bone will take L1 @ 50 amp and tie it to the 30 amp leg. Delivering 120 volts @ 50 amps to a 30 amp service BUT the 30 amp main is all you get. L2 in is not used.

 

[Back2PA]

The dog bone will take L1 @ 50 amp and tie it to the 30 amp leg. Delivering 120 volts @ 50 amps to a 30 amp service BUT the 30 amp main is all you get. L2 in is not used.

My apologies for incorrectly stating the question. I was asking about a 30 amp pedestal, then using a 30 to 50 dogbone (50 amp RV) and Alfa38 answered.