On 50amp one circuit goes out

[RvExplorer]

New 2018 Vista XL 35f. Hooked up 50amp shore power, hot day and both ACs running, tv on and the DW fires up the hair dryer and the system recognizes the draw and gently powers down the rear ac just like it is supposed to. Problem is the 30amp circuit for the rear ac won't come back up. Tried everything I could think of (circuit breakers both inside the coach and on the pole. Finally in desperation I unplugged the 50amp at the post, counted to 10, plugged it back in and every came back to normal. This happened a couple more times over the weekend. I also use a surge/polarity protector. Dealer says if it happens at another rv site, bring it in. Anybody know anything that might cause this or have a suggestion?

[Matterbery]

Have the campground check their 50 amp breaker as one side of the breaker will have burned connects and the other side will be ok. The amp draw thru the burnt connects causes the system in the unit to shut down. I have seen this problem at several different rv parks.

[Wayne M]

Low voltage on the pedestal (One leg) us most likely low. Could be from loose connections at the pedesal or arcing or loose connections at the distribution box.

[RvExplorer]

Thanks to both of you. This happened on the maiden voyage. We set out again in a couple of week and will have 50 amp service in a very nice park so that will be a good test.

[jerichorick]

Originally Posted by RvExplorer

New 2018 Vista XL 35f. Hooked up 50amp shore power, hot day and both ACs running, tv on and the DW fires up the hair dryer and the system recognizes the draw and gently powers down the rear ac just like it is supposed to. Problem is the 30amp circuit for the rear ac won't come back up. Tried everything I could think of (circuit breakers both inside the coach and on the pole. Finally in desperation I unplugged the 50amp at the post, counted to 10, plugged it back in and every came back to normal. This happened a couple more times over the weekend. I also use a surge/polarity protector. Dealer says if it happens at another rv site, bring it in. Anybody know anything that might cause this or have a suggestion?

One of the common problems with all electrical systems, especially the new builds, is loose wire connections in the ATS and service panel. For the older, many miles on the road, rigs it is simply vibration that loosens the screws. For the new builds it is poor attention given by the installers of the equipment.


On of the more common, and most expensive, failures is when the neutral from the pedestal comes loose. This puts 240VAC onto your service panel. The inverter and MW usually fail under this condition. For this reason alone I check my electrical connections each year. Which reminds me. Time for the check.

[RvExplorer]

At the risk of sounding dumb, what is the ATS and where would I find these screw connections that I should keep and eye on?

[luvlabs]

The ATS (Automatic Transfer Switch) is located where your shore power cord comes into the RV. The loose connections being referred to are in the ATS with the connections to the shore cord, the generator, and the main power cord back into the RV.

You can check these pretty easily and safely - unplug the shore power cord, make sure the generator is off, and remove the cover to the ATS. Using the appropriate tool, check the tightness of each connection. They don't have to be gorilla tight, just snug.

[Ray,IN]

Originally Posted by luvlabs

The ATS (Automatic Transfer Switch) is located where your shore power cord comes into the RV. The loose connections being referred to are in the ATS with the connections to the shore cord, the generator, and the main power cord back into the RV.

You can check these pretty easily and safely - unplug the shore power cord, make sure the generator is off, and remove the cover to the ATS. Using the appropriate tool, check the tightness of each connection. They don't have to be gorilla tight, just snug.

I might add, make sure your inverter is off, otherwise one might have a shocking time tightening the screws.

[Tailhooker]

Newbie Question:

Is the ATS the relay I hear activate when I plug in or unplug shore power?

[SarahW]

Originally Posted by Tailhooker

Newbie Question:

Is the ATS the relay I hear activate when I plug in or unplug shore power?

Yes. A slight "thump."

[Tailhooker]

Thanks SarahW - a slight "thump" is what I hear!

[jerichorick]

I have been thinking about this problem a bit. Here are some general thoughts.


1/ Try not to plug into a hot service. If you miss the neutral, even briefly, you could damage your electrical system.
2/ Watch the power monitoring panel voltage as the loads come on line. You should not see the voltage drop below 110V at any time. If it does there is a poor connection someplace or a problem with the park power.
3/ On 30A or generator loads will be shed automatically by the EMS (energy management system). In the case of the generator, the breaker on it may trip if the loads are too great.
4/ My coach has a great feature. On 30A, if the shore power is maxing out, the inverter will supply supplement power. I have seen it do this a few times when running the microwave.

[grtharris]

RvExplorer When you are connected to a 50 amp service none of the loads will shed/turn off. As mentioned above somewhere in the electrical system, more than likely the power pestle, you where loosing one leg of the 50 amp service and ending up with a single leg of a 30 amp service.

[Upinsmoke]

I agree that the problem is likely a lost leg, or some other problem, in the pedestal but if OP is using a surge protector, don't all of them have indicator lights that show the source of a problem? I believe I would have headed right to the protector to see what is was indicating. Just a thought.

[RvExplorer]

I don't recall seeing any change in the lights on the surge protector. Odds are its the pedestal. Its at a private yacht club installed by a lot of volunteer labor. I head out this Wed to a nice park with 50 amp and we will see if the problem arises again. Thank you all again for the tips!!