Chasing an electrical gremlin!

[Land-roamer]

Ok, so my 70's Alaskan restoration/re-use project is moving along. I have re-caulked the entire camper (seals, windows, etc.) and it has successfully passed a test during recent torrential rains, with no signs of water coming in.

Now I'm trying to diagnose and repair a nagging electrical issue.

Problem: when I plug an extension cord into the 110v external socket, the house circuit trips the breaker (GFI) or blows a fuse.

What I have done so far:
- checked out the wiring at the external socket and it's good, no shorts.
- checked the wiring and connections at the single breaker box, and I can't figure out if things are where they should be (I'm not an electrician nor do I have a proper wiring diagram for that box). So I disconnected the wires coming in and going out
- I've ascertained that there is continuity and no shorts between external socket and the input to the breaker box
- checked the wiring and connections at the two cone lamps in the back, and it looked generally good (redid some connections for good measure); good continuity with the 3 wires coming out of the breaker box (Hot/black, Neutral/While, Ground/bare).
- checked the wiring and connections at the combination overhead lamp over the sink: the 110v socket looked like it had been replaced, and the Hot and Neutral wires were reversed on the socket connectors, not sure that is an issue, so put them on the right connectors; ascertained good continuity with the 3 wires coming out of the breaker box
- checked the wiring and connections at the single inside wall socket (behind the fridge): ascertained connectivity with Hot and Neutral, but Ground looked a little wonky (not full continuity with ground wire exiting the breaker box); replaced the double socket because it looked cracked; once in place, lost the ground continuity; took the wires off and rechecked continuity and the ground is now open.

So: do I have a problem with an open ground at that inside double 110v socket? How do I diagnose further since the wire running to it is hidden by the woodwork?

Is there something else I should do to further troubleshoot?
Does someone have instructions on how to wire the breaker in that box, in case it was improperly wired before I disconnected everything? Here's a pic of my box, both white wires go to same terminal. The wires on left are connected to external 110v socket on the camper, the ones on the right go to the light and plug circuits in the camper.

Have any of you rewired parts of your Alaskans and how much of a job is it?

[I HATE electrical problems and gremlins...]

And after the 110v circuit is sorted out, I still need to figure out how to setup an adequate 12v system to feed the 12v lamps, the new Fantastic Fan I installed, etc...

Thanks for your help and advice.

--Robert

p.s. oh yeah, also will be ordering tie-downs so I can finally mount it and secure it to my 96 Dodge 4x4. Hopefully I'll have it all running and installed for an initial camping trip this summer... Here's a picture of my truck beside the raised camper, to give an idea of what it will look like when it's on the truck.

 

[K7MDL]

This may sound silly, sorry, but did you ensure your extension cord is not the problem?

As for inside, the open ground issue: Does your bare ground wire connect to the white wire anywhere you can see? If it does then you have 2 paths for ground and that reduces teh chances of seeing an open in a ground path. Otherwise you have a wire break or poor connection going on. Also some dual receptacles can have the bridge link between the 2 halves broken out to allow separate power into each half, but the ground stays connected.

With the camper unplugged from shore power, and all loads removed, you should not see any shorts between the white and black wires, breaker open and closed. Then measure between the ground and white (may be shorted if gnd is connected to white at any location, else open), then ground and black (should be open).

 

[Land-roamer]

This may sound silly, sorry, but did you ensure your extension cord is not the problem?

As for inside, the open ground issue: Does your bare ground wire connect to the white wire anywhere you can see? If it does then you have 2 paths for ground and that reduces teh chances of seeing an open in a ground path. Otherwise you have a wire break or poor connection going on. Also some dual receptacles can have the bridge link between the 2 halves broken out to allow separate power into each half, but the ground stays connected.

With the camper unplugged from shore power, and all loads removed, you should not see any shorts between the white and black wires, breaker open and closed. Then measure between the ground and white (may be shorted if gnd is connected to white at any location, else open), then ground and black (should be open).


I believe I had tried 2 extension cords and result was similar. But indeed, hopefully it wasn't as simple as that (given all the wiring teardown I've done!

I can't see any place where the ground touches the white wire, but can only see places where the wires come out of the walls-ceilings. I would assume that no harm could come to the wire in the hidden areas...

No, the dual 110v receptacle bridge links were ok, in both the original and the replacement one I put in.

I should point out that before I started this teardown, I checked the external 110v connector, and the black (hot) and ground were shorted! When I disconnected all the wiring on both sides of the breaker, it's now open.

I'll continue my investigations... I feel rather silly, I mean this is a very simple electrical setup in these older Alaskans. As I said above, the only question for me is the wiring in the breaker box, so I need to educate myself on what a typical hookup should be like, and compare to how it was wired before.

Thanks for your suggestions.

 

[pods8]

Also keep in the back of your mind that solid copper wire like used in your camper (and also in FWC, etc.) is not designed to be used in our campers. In a house it is stationary, in a camper it is constantly being vibrated and the solid piece can fatigue/crack over time. Hopefully that isn't the issue for you but if you rule everything else out...

 

[Land-roamer]

Also keep in the back of your mind that solid copper wire like used in your camper (and also in FWC, etc.) is not designed to be used in our campers. In a house it is stationary, in a camper it is constantly being vibrated and the solid piece can fatigue/crack over time. Hopefully that isn't the issue for you but if you rule everything else out...

Good point, hadn't thought of that...

I plugged the house extension cord into the camper's external connector and it didn't trip the GFI, so far so good. Mind you, the wires are disconnected at the breaker box so no surprise. I checked the voltage at those wires and got 110v between the hot (black) and neutral (white), BUT, I also got 110v between the hot (black) and ground wire. Is that normal?

I'm thinking of running a separate ground wire to the dual receptacle, since the original ground wire is no longer functional. Not sure where I'd run it though, but I DO need an AC outlet in the camper, since this is the only one (for tv, small appliances, laptop, etc.). Any suggestions?

Speaking of that outlet, I'm also likely going to be taking the non-original fridge out of there (the PO put in some small 110v bar fridge and made it fit where the original Dometic was). I'm either going to use a good old Coca-Cola cooler (ice, baby), or possibly one of the efficient 12v variety. Not sure there's much point in having a 110v fridge in there, as I don't see myself being plugged into shore power in any campground for a lengthy period of time.

 

[Mark W. Ingalls]

Good point, hadn't thought of that...

I plugged the house extension cord into the camper's external connector and it didn't trip the GFI, so far so good. Mind you, the wires are disconnected at the breaker box so no surprise. I checked the voltage at those wires and got 110v between the hot (black) and neutral (white), BUT, I also got 110v between the hot (black) and ground wire. Is that normal?

I'm thinking of running a separate ground wire to the dual receptacle, since the original ground wire is no longer functional. Not sure where I'd run it though, but I DO need an AC outlet in the camper, since this is the only one (for tv, small appliances, laptop, etc.). Any suggestions?

Speaking of that outlet, I'm also likely going to be taking the non-original fridge out of there (the PO put in some small 110v bar fridge and made it fit where the original Dometic was). I'm either going to use a good old Coca-Cola cooler (ice, baby), or possibly one of the efficient 12v variety. Not sure there's much point in having a 110v fridge in there, as I don't see myself being plugged into shore power in any campground for a lengthy period of time.


For 110V, get yourself a basic book on home wiring. You can find them at Home Depot. While you are there, get a circuit tester that looks like this:

The white and bare copper wires are bonded together at your house's distribution panel, so yes, that's normal.

Unless I knew for sure what those wires do and where they go, I would make sure to keep them de-energized.

 

[Rusty]

Robert,

Electrical problems are best not solved online. Confusion runs amok and shorts in a camper can be disastrous.
That being said...your circuit breaker panel is set up for one or two breakers. Typically there is only one 15 amp breaker installed. The black or hot or line voltage wire installs in one end of the circuit breaker and the white, neutral and bare ground are bonded to a small bus bar with 10-15 small screws for locking the wires to the bar.

If your breaker is disconnected and the breaker doesn't trip at the house your wire from the exterior plug and the breaker are OK. The only circuits are to the outlets...sometimes 2 and sometimes 1...and the lights. Sometimes folks put too large a bulb in the lamps and fry the wiring behind the mounting plates. Take the fixtures off the wall with the two small thumb screws and check the wires behind the lights...make sure you don't have bulbs that exceed the rating for the fixtures...I think mine are 20's or 40's.

Most of the wiring in the older Alaskans is installed in the filled foam top where the foam locks the wiring in. Loose wires at points of connections or cracked and heat damaged wires at the lamps will represent most of the problems you'll encounter. Wiring 120 between the top and the bottom section is a little tricky. If you should decide to do that I've got a few solutions which have worked well over the last 30 years.

Remember, tighten all screws carefully, replace wires with appropriate colors, where possible, solder wires and tape ends rather than using a scotch lock...there, is where vibrations mentioned will take there toll. Neatness counts....a neat well wired unit has wires bent at 90 degrees and protected from contact

As far as the refer goes....12v is the most inefficient part of refrigeration...it will suck your battery dry in a heart beat and not even bother to tell you....12v is primarily installed for transporting from one location to another. If you're planning long trips an inverter and a good sized wire will be the way to go. 120v and propane are the 2 functional methods for refrigeration. 120 when you can and propane when you can't. Venting is an issue with Alaskans and I installed one with a few upgrades and the pics are in my folders.

Good luck, bear down on it and don't let it get the best of you....BTW....even electricians have short problems now and then....longer problems elswhere

 

[Land-roamer]

(...)
Electrical problems are best not solved online. Confusion runs amok and shorts in a camper can be disastrous.
That being said...your circuit breaker panel is set up for one or two breakers. Typically there is only one 15 amp breaker installed. The black or hot or line voltage wire installs in one end of the circuit breaker and the white, neutral and bare ground are bonded to a small bus bar with 10-15 small screws for locking the wires to the bar.

If your breaker is disconnected and the breaker doesn't trip at the house your wire from the exterior plug and the breaker are OK. The only circuits are to the outlets...sometimes 2 and sometimes 1...and the lights. Sometimes folks put too large a bulb in the lamps and fry the wiring behind the mounting plates. Take the fixtures off the wall with the two small thumb screws and check the wires behind the lights...make sure you don't have bulbs that exceed the rating for the fixtures...I think mine are 20's or 40's.
(...)

Thanks Rusty, for the encouragement and words of advice!

As you can see from the picture of the breaker panel I put in my post, there is indeed a single 15amp breaker, and the only circuits I have are 2 lights in the back, one light over the sink, and a single outlet behind the fridge. As far as the wiring in the box goes, the incoming black hot wire (on the left in the photo) is connected to one end of the breaker connector, and the outgoing black wire (on the right) to the breaker connector at the other end. Both incoming and outgoing white neutral wires are connected to the same screw on the bus bar (is that ok?) and both ground wires are simply twisted together and connected to a screw on the box (no connection to the bus bar, again, not sure that's ok). I'd like to rewire the breaker box but would like to make sure I do it right.

I checked all light fixtures and everything seems ok. I'll check the wattage of the lamps as you suggested.

The only hiccup I found is the lack of a working ground wire at the fridge outlet. By the way, all the exposed wiring I see in the upper storage compartments use some kind of crimped connector to connect wires together. About the issue of soldering and vibration, I have often read that a crimped connection was better than a soldered one to prevent vibration-related issues... Crimping, then soldering would probably be a very good approach is one was so inclined, and had the time.

Thanks for the thoughts on the fridge issue, but that will be down the road for me, not essential at this time. First the wiring, then check out the propane connections, then get the camper on the truck, etc...

Cheers!

 

[Rusty]

Robert,

The bare grounds to the box are appropriate. The two neutrals should be separated and each have their own screw on the bus bar (four screws)...looks like the bar is large enough for another circuit breaker if you should decide to upgrade.. The method for crimping bands and plastic or rubber covering was the standard during the time of the 60-70 builds. Electrical standards change with the wind and twist locks or just twists were in favor for a bit...now it's twist together 3 or 4 times and lock. I'm old fashioned and I twist and solder, then tape with a good electrical tape....good being the key word.

The extension cord has been mentioned before....make sure you check the connections on the cord ends. They sometimes will come loose with all the tugging and can short out.

Make sure you keep all the wires tucked nice and neat around the inside edge of the box...that way further work can be accomplished without getting tangled up in the wire excess. Tighten and re-tighten with as large a screwdriver that will fit in the slot...torque, loose screws can cause broken circuits.

Look carefully for the ground wire at the outlet if the wire at the CB panel has a ground it should be there...with your's a 1970 there should be a 3 prong outlet and 3 wires....you may need to remove the outlet box to access the wire for inspection.

One thing....and it may seem trivial....always remove the extension cord from the plug before you begin electrical work. I can't tell you how many times someone has told me "the lines dead", only to find current with a circuit checker. I always turn the CB off and check the line voltage before beginning any electrical work. Removing the plug insures your safety and almost guarantees hugs from the family that evening....almost. Learning electrical can be a shocking experience....

 

[Land-roamer]

Thanks again Rusty. Have no fear, I don't do ANY work on there without the shore power being disconnected.

I basically taped the ends of the 3 wires at the fridge outlet, the ground is non-functional so I'll have to figure out what to do to get that outlet functional again at some point.

I re-assembled the CB panel. In and out white wires to separate screws on the bus (they were previously attached to the same screw). Not sure it really matters to separate them since there is connectivity on the bus, but I did. Then the black wire on the supply side to the screw connected to the plate to which the end of the breaker (with the copper connectors) attaches. The other black wire screwed into the other end of the breaker. Twisted the ground wires together and fixed to inside screw on CB panel side. Snapped the breaker in place. Left it in the off position. Checked and there is connectivity between white and ground, which according to Mark is ok.

Checked the external connector on the side of the camper. The white and ground have connectivity. Black and ground open. Black and white open.

Plug in the extension cord and the GFI trips immediately.

I'm stumped. I'm frustrated. I hate this. My back hurts.

Time to take a break, mull over some more, read books, educate myself. Maybe get a new CB panel and/or breaker?

I'm wondering how the seller had it working in his garage, because when I went to see it he had it plugged into shore power, and had the lights on, the fridge, etc. When I experienced problems at my house I asked him and he said he never had problems...

 

[K7MDL]

With that description, I would suspect your GFI outlet itself, or the cords. Does a saw or other 3 wires device plugged into that GFI outlet work fine?

 

[Land-roamer]

With that description, I would suspect your GFI outlet itself, or the cords. Does a saw or other 3 wires device plugged into that GFI outlet work fine?

You know, when this first showed up in the Fall, before putting away the camper for the winter, I had the same idea. Bought a new GFI outlet and installed it, same problem. Then I recall plugging the extension cord into a house circuit and all seemed to work. Since then, nada.
I'll get another long cord to try, and test the GFI on another 3 wire device as you suggest.
Thanks for all your help.

 

[camelracer]

I would think that your GFI problem is that the neutral and ground are connected on the load side of the GFI plug. This will allow current to flow through both the neutral and ground wires whichever has the least resistance. The GFI will trip with any current on the ground circuit.
As was stated earlier the neutral and ground are common at the house service panel but this is on the supply side of the GFI and will not cause a ground loop in the GFI.

Good luck

 

[Land-roamer]

I would think that your GFI problem is that the neutral and ground are connected on the load side of the GFI plug. This will allow current to flow through both the neutral and ground wires whichever has the least resistance. The GFI will trip with any current on the ground circuit.
As was stated earlier the neutral and ground are common at the house service panel but this is on the supply side of the GFI and will not cause a ground loop in the GFI.

Good luck

Hi.
I took the breaker box out. It's quite obvious that the neutral bus is grounded to the box (long screw screws into the box). With the ground wires (in and out of the box) grounded to the box, that's how I arrive at my neutral and ground connection in the camper. Should I just make sure that the neutral (white) and ground are NOT connected at the box?? I suppose in house wiring one wouldn't want to do that, but should that be done in the camper breaker box to prevent the GFI from tripping??
I'll go out and buy a new breaker box, mangled the original one a bit taking it out. I'll get a new breaker while I'm at it.
Thanks.

p.s. would these 70's Alaskans possibly have been wired BEFORE the GFI started being used?

 

[Land-roamer]

Couldn't find a similar-sized breaker box so will reinstall the old one.

Based on the following thread, I deduce that the breaker box inside my Alaskan should NOT have had the neutral and ground bonded, as was the case.

My link

So I'll remove the neutral bus screw that connected it to the box (bonding neutral and ground) and hopefully all will be good after that.

 

[Land-roamer]

Thanks to PanelRacer for pointing me in the right direction about the neutral and ground. Then that link I provided (pro electrical forum) cleared things up nicely. Once I ensured neutral wasn't bonded to ground in my box, reinstalled everything, all works just fine!!! I also replaced the 3-wire 110v crimp connections in the compartment above the fridge (supplying AC to lights and the inside outlet) and the bad ground on the inside outlet resolved itself (must have been corrosion inside the crimp connection). Checked it with an AC tester and it's all fine.

SO: after all that the moral of the story is, kids: make sure your old Alaskan doesn't have neutral and ground bonded in the breaker box!