Any Electricians out there?

[Richard Barnes]

Good morning guys. I woke this morning with an electrical problem of some sort in my coach and not being an electrician I turn to the experts.

I'm connected to 50amp service in an RV park in Long Beach, CA. Last night everything was fine with ac power to both inverters and to the breaker panel. This morning I have only shore power power on the right side of the panel (inverter shows good ac in) and the other inverter shows no ac input and it is in inverting mode to provide power to the left side of the panel. I'm managing power to keep the house batteries at their peak and so far so good with that. I started the generator and both inverters show good ac in and work fine providing power to each side of the panel. Everything works fine with the generator on.

I have a surge protector and the read out shows that everything is fine coming from the 50 amp service. I've checked the connections to both inverters and everything looks okay. I had the shore power connected to the port inlet and decided to move it to the starboard inlet to see if there was any difference. Interestingly, after doing that the inverter that previously showed good ac in on the port side now began to invert and the one that had been inverting now shows good ac in.

There has been no damage to the shore power cord and whatever happened did so in the middle of the night. Guys, any advise will be appreciated.

[ajducote]

Just a wild guess, but it sounds like a transfer switch problem? Since gen power works on both legs and shore power only works on 1 leg, where does that connection take place? I do not know Liberty systems so I am just making wild speculation. Hopefully the Liberty crowd will chime in soon.

[Jon Wehrenberg]

The 50 amp breaker on shore power is to trip on both sides if one side has a short or fault. However it is possible if the breaker is faulty one side may trip and the other remain connected.

Just for the chance that may have happened reset the 50 amp breaker in the shore power box and see if that makes the problem go away.

[sawdust_128]

Do what Jon said and start metering to find out where it is that power stops happeneing.

[garyde]

There is a breaker inside my coach on the 1st bay port side which is 50 amps. Sometimes I accidentally knock it off putting things in or taking things out. Check that out as well.

[Richard Barnes]

Thanks Jon, I tripped the breaker and that did not work. I then tested my power cord and at the female connection I have voltage only on one line. The other two lines have no voltage and I'm guessing one is the ground. The voltage coming from the surge protector is fine. It appears the power cord has a problem somewhere. Thanks for your help. It looks like a new connection or cord in my future!

[Jon Wehrenberg]

Disconnect your cord at each end and test for continuity. That's the simplest and safest way. You might want to keep a record of which terminal on the cord female end corresponds with which blade on the male end for future reference. Sounds like one of the hot lines is open.

[Richard Barnes]

Jon, thanks for the help. I hate to show my ignorance but what is meant by a "hot line is open?" I'll check the continuity of the circuit as soon as I can get back to the coach this afternon. Thanks again.

[Kevin Erion]

Richard, give me a call, I might be able to help you with your cord. Call anytime, this is my cell # 714-342-8588
Kevin

[Jon Wehrenberg]

Richard the easiest way to explain it is to look at the plug that goes into the shore power outlet.

It has two flat blade lugs on the left and right. Those are the "hot" terminals. They would be both black wires, or in some installations one would be red and the other black. The flat blade lug centered above those two lugs is the common. That would be a white wire. Between the two "hot" lugs in your terminal box in the kitchen is 240 volts. Between either "hot" lug and the common would be 120 volts, and the fourth lug, the "U" shaped one is the ground and its wire would be green.

You may not have a problem with your coach so before you tear into things to try to find the problem just verify you are getting 120 volts between both hot receptacles in the the shore power outlet and the common receptacle. The only reason I haven't moved from blaming the shore power is the abysmal maintenance most campgrounds do on their shore power outlets, usually not responding until someone fails to get power. It could still be a bad breaker or even a loose connection at the breaker. Once you have verified good power at the box, then do the research on your coach. A loose connection at the breaker can get so hot due to resistance it can literally burn the wire off it. With a tester on a circuit with a failed wire you can still measure line voltage, but the circuit is so bad it will not carry a load. It is no big deal for the campground to take off the deadfront on the box and do a check of the connections and circuits.


Then call Kevin.

[Alek&Lucia]

Richard,

Check this link below:

http://myrv.us/electric/

Alek

[gmcbuffalo]

Richard have you tried plugging in to your neighbors outlet, and see if anything is different? LIke Jon said you may have a bad box. How do your lugs look bright and shiney brass? If not clean them.
GregM

[phorner]

I had a problem with the exact same symptoms. In my case the surge protector was the problem. The LED read fine because the power coming into the surge protector was fine.... but I was not getting power through the surge protector on one leg.

I would try connecting without the surge protector to remove one variable and determine if the surge protector is contributing to the problem. Of course, you could also simply measure the current at the outlet of the surge protector to verify if it is working or not.

[Richard Barnes]

As always I appreciate the immediate help you guys offer and I'm always somewhat red faced when I haven't checked the obvious. Paul was right on target! Because the surge protector was relatively new, I didn't check the power coming through it. The LED readout showed no error code. When I disconnected it and plugged the shore power cord directly to the 50amp service the problem was resolved. I've called Progressive Industries and they are sending a new surge protector overnight.

Many thanks to those of you that responded especially Ray Davis who offered to come to Long Beach over the weekend to help me trouble shoot the issue and to Kevin Erion who offfered to test and make any repairs needed to my shore power cord. You guys are the best!

[phorner]

Yep.... mine was a Progressive Industries unit as well.

Glad it was an easy fix......