Sudden Loss of Power to 3 circuit breakers

bobnelms · 04-22-2021, 10:32 AM

Hi all,

I have a 2016 Keystone Cougar 5th wheel with an electric fireplace. This morning, I noticed that it was not working. I removed it, plugged it into another outlet and it worked just fine.

I checked the GFCB, and it had not tripped. Just to make sure, I tripped it and tried the outlet again but it still was not working.

After taking the cover off the breaker panel, I tested the AC voltage at each breaker. 120, 120, 120, MAIN BREAKER, 1, 1, 1.

In other words, there were 3 breakers that only read 1 V AC.

Any ideas what's going on?

Thanks

**flybouy** · 04-22-2021, 10:50 AM

Some more info would help. What model number is your trailer? Is it a 50 amp or 30 amp panes? How's it plugged in, 50 amp to 30 amp dog bone? Plugged into a 15 amp outlet with a dog bone? From your description it sounds like a 50 amp panel that you've lost power to one side.

**chuckster57** · 04-22-2021, 11:06 AM

Quote:

Originally Posted by flybouy

Some more info would help. What model number is your trailer? Is it a 50 amp or 30 amp panes? How's it plugged in, 50 amp to 30 amp dog bone? Plugged into a 15 amp outlet with a dog bone? From your description it sounds like a 50 amp panel that you've lost power to one side.

I’m think the same thing, 50A service 1 leg not getting power

bobnelms · 04-22-2021, 11:13 AM

It's a 2016 Cougar 5th wheel -- polar package -- 3 slides -- 50 amp service.

Yes, I have it plugged into our shed using a 50 to 30 to 15 amp connector.

And yes, it does sound like I lost power to one side of the breaker panel.

So what do I do now?

**chuckster57** · 04-22-2021, 11:18 AM

It’s hard to say because I don’t know how comfortable you are using a Volt Ohm meter on a live circuit. I’m comfortable with myself, but it can really HURT you if you goof.

bobnelms · 04-22-2021, 11:33 AM

Well, if you suggest something and I'm not comfortable don't worry -- I won't do it.

**flybouy** · 04-22-2021, 11:41 AM

Couple more questions. Did it ever work with these adapters before? If it did, has anything changed? Have you tried cycling the main breakers in the camper (turn them off, then back on)?

**flybouy** · 04-22-2021, 11:48 AM

Here's a diagram of a 50 amp 14-50R plug. You can Plug in the dog bone adapters and you you should get 120 volts between each X to W, X to G, or Y to G or Y to W. You will not get 240 volts from X to Y as they will be the same phase thru the adapters. Hope this is clear enough.

**JRTJH** · 04-22-2021, 11:57 AM

Depending on the way the "15 amp to 30 amp" adapter and the "30 amp to 50 amp" adapter are wired, there may be noting at all wrong....

First, do you have an EMS in the trailer ???? Not a surge adapter, but an EMS???

Next, has this trailer using this same (exact) adapter series (all plugged in just like they are now) worked in the past on the same outlet ????

If yes, then troubleshooting is needed...

If "I don't know" then I wouldn't do anything until you have a chance to plug the 50 amp trailer shore power cord into a 50 amp campground pedestal....

If this adapter connection hasn't been verified in the past, then my guess would be that there's an issue either with the EMS (if one is installed) recognizing correct power input or one of the adapters just "isn't talking to the others"...

bobbecky · 04-22-2021, 12:33 PM

You reset the small breaker but did you reset the 50 amp main breaker? It’s possible that it tripped on the one side.

bobnelms · 04-22-2021, 02:59 PM

Yes, I have been plugging our RV into a 15 amp circuit from our shed ever since we got the unit 4 years ago. This is the first time this has happened.

Not sure if it matters, but the 15 amp circuit is a GFI itself.

bobnelms · 04-22-2021, 03:01 PM

No, I do not have an EMS on this unit.

**JRTJH** · 04-22-2021, 06:20 PM

Based on what you showed from the voltmeter checks:

120 120 120 main/main 1 1 1

Did you by chance check for voltage on the main/main ???

My guess is that you've got 120 on the left main and 1 on the right main...

That would mean that "leg 1" on the left side of the main is live and "leg 2" on the right side of the main is dead....

If there is 120 VAC on both the left and the right screw lugs on the main circuit breaker, then the problem is either the main circuit breaker or the power enter buss bar.

If there is 120 VAC on the left screw lug and no voltage on the screw lug on the wire connected to the right main side of the circuit breaker, then the problem is "from the power center back to the 15 amp plug. If there is 120 on the screw lug on the right main side of the circuit breaker, then the problem is in the power center....

My guess is that one of the adapters in your "shore line" has an open wire... Since it's common to both legs at the 15 amp adapter and at the 30 amp adapter, that leaves (IMHO) a problem from the 50 amp plug that's connected to the 30 amp adapter to the main circuit breaker...

You might start troubleshooting by unplugging the trailer at the 30/50 amp adapter, drag the male end of the 50 amp shore power cable into the trailer and use an ohmmeter to measure from each side pin to the buss bar that all of the branch circuit breakers clamp onto. My guess is you'll find a "direct short" (0 Ohms) on the side that previously had 120 volts and an "open" (infinity) on the side that previously had 1 volt. That will confirm that you have a broken wire "somewhere" in your 50 amp shore power cable.

To me, that's the "most logical next step" in troubleshooting, but if it's not that, don't give up, there's other checks we can do, but I think you'll find an open wire from one of the plug ends to the buss bars.

bobnelms · 04-23-2021, 04:39 AM

JRTJH, this is great information. I'll do exactly as you suggest and report back later today.

One followup question. After I disconnect the shore power and drag the plug into the RV, you suggested testing each leg of the plug using and ohmmeter -- placing one lead of the ohmmeter to a leg on the plug and another lead on the common bus bar that all the breakers plug into.

This means I have to remove some breakers to access that common bus bar, right?

Thanks again

**JRTJH** · 04-23-2021, 05:55 AM

I believe you have a WFCO 9560 power center. You can download the owner's manual/installation manual here: https://wfcoelectronics.com/wp-conte...-Manual-RP.pdf

FIRST: UNPLUG YOUR TRAILER SHORE POWER CORD !!!!

Then, open the front door of the power center to get access to the circuit breakers/fuses.

You will see 4 screws that hold the front panel in place.

Remove those screws and the front panel will come off the unit, exposing the circuit breakers and the wiring to them.

That's where you will see the large shore power cable come into the power center and the 4 wires in that cable will be routed to 1) the ground bar 2) the neutral bar and 3 & 4) to the main circuit breaker "side 1&2.

Use your ohmmeter to measure for continuity between the main breaker lugs (where those cables are attached to the circuit breaker) and to each of the buss bars. That will check for continuity INSIDE the circuit breaker. Then check for continuity from the male end of the shore power cable (that you dragged into the trailer) and those same main breaker lugs. That will check for continuity of the actual shore power cable and the male plug on its end.

This will confirm both the circuit breaker is functioning and that the shore power cable is serviceable.

The diagram showing how the wires are routed and connected inside the power center start on page 11 of the manual you can download above.

AGAIN: DO NOT REMOVE THE POWER CENTER FRONT PANEL UNTIL AFTER YOU UNPLUG THE SHORE POWER CABLE !!!!!

rlh1957 · 05-02-2021, 08:09 AM

There are usually more than one GFCI receptacles in an rv.
Some even have it on a breaker.

If a wire came loose from a receptacle the plugs down line would becaffected.

cavie · 05-02-2021, 08:18 AM

Quote:

Originally Posted by flybouy

Here's a diagram of a 50 amp 14-50R plug. You can Plug in the dog bone adapters and you you should get 120 volts between each X to W, X to G, or Y to G or Y to W. You will not get 240 volts from X to Y as they will be the same phase thru the adapters. Hope this is clear enough.

30 amp 240-volt locking receptacle is not used in the RV world! It has no neutral and the two hot legs are 240 volts between them 14-50P and L6-30R are not used in the RV world.

bobbecky · 05-02-2021, 11:45 AM

Quote:

Originally Posted by cavie

30 amp 240-volt locking receptacle is not used in the RV world! It has no neutral and the two hot legs are 240 volts between them 14-50P and L6-30R are not used in the RV world.

Good call!! I can not believe how many sites there are purporting to show the correct way to wire RV outlets and showing 30 amp outlets with two hotlegs. Maybe that's why so many 'electricians' don't understand the correct way to wire them. Definitely disregard the above wiring diagram as it will burn up an RV rig.

This site has the correct placement of the wires with the correct NEMA TT-30 receptacle. https://electricproblems.com/how-to-...0-amp-rv-plug/

And this is how to wire a 50 amp receptacle. https://electricproblems.com/how-to-...0-amp-rv-plug/

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