Community Forums

johnwr · 07-30-2011, 11:55 PM

The title was meant to get your attention. This can be a life threatening situation.

Today we lost power to one of the General Purpose circuits on the Sub Panel which got me started on the troubleshooting process. In the end, the problem was a tripped GFI outlet, but what I came across in the process of determining that, was alarming.

First, when I plugged a receptacle fault indicator into one of the outlets on the circuit, it indicated that there was power but the polarity was reversed. When I tested the outlet with a Multimeter it showed that I had 120 VAC between the HOT and the GROUND, but only about 35 VAC between the HOT and NEUTRAL (the wide blade), so I presumed that I had a NEUTRAL wiring problem. When I pulled the cover off the Sub Panel I immediately noticed that the #10 bare copper wire coming from the CHASSIS GROUND had come loose from the GROUND BUS BAR, and one of the NEUTRAL (white) wires on an adjacent NEUTRAL BUS BAR was loose. Either or both of these wiring defects could create a potential for electrical shock. It was obvious that the CHASSIS GROUND had never been secured in it's GROUND BUS BAR location. There may be other ground paths to the chassis but this is the primary designed path, so it's essential that it be working from a safety perspective. The coach should have never gone out the door with this defect, but fortunately there wasn't a safety incident.

Just a reminder for all of us that along with the connections at the Generator, and the connections at the Transfer Switch, normal maintenance should include a check of the major electrical connections.

mudpuppy · 07-31-2011, 06:14 AM

Good advice. Now if they would stop burying the connections behind the trim so it looks pretty we could actually be more proactive.

Dr4Film · 07-31-2011, 06:37 AM

With any Home on Wheels, it is possible that connections could loosen up over time especially with the different types of road conditions we drive on. If anyone has ever driven the I-5 corridor in California, you will agree.

Routine inspection of secure electrical connections is important. It is also very easy to have one of those circuit testers where you simply plug it into an outlet and immediately it will tell you whether you are properly wired or not. If you get an error, then go looking for a loose connection.

Dr4Film ----- Richard.

scgator · 07-31-2011, 06:48 AM

Quote:

Originally Posted by mudpuppy

Good advice. Now if they would stop burying the connections behind the trim so it looks pretty we could actually be more proactive.

EXCELLENT POINTS: OWNERS AND MANUFACTURERS NEED TO HEED THIS ADVICE; My last working position was as a licensed electrical contractor in the state of South Carolina, and discovering "potentially dangerous" situations is more common than you would think in homes. The fact that an RV is production line built will, in most cases insure a better quality control process, but not always.,,,,,,,,,,,,,,,,,,,,Manufactures NEED to engineer their vehicles in such a way as to be able to allow a competent (professional) person to be able to access their system easily. OSHA & NEMA requires that ALL electrical panels in a "brick and mortar" structure to have easy access, and at least a 3'-0" clearance in front of the panel opening. This is so that, if there is an emergency, you will be able to get to the main breaker quickly and unhindered to cut it off. The outdated idea of all electrical must be built in is from the early days of the auto industry and needs to be mandated into the 21st century............I would much rather have a "decorative" access panel to the main connections of my system than to have to tear my coach apart for a simple repair or adjustment.

Manufacturers PLEASE listen........I, (can't speak for the general populous) would like to see this in the near future! You can't just take it for granted that we will never have any issues to repair.

Norm4015 · 07-31-2011, 07:01 AM

During my annual routine service I check and tightened if necessary all connections in the circuit breaker panel, in the automatic transfer switch and any ther connections I can easily reach. I have found loose / bad connections in two new motorhome I've bought. Since I have done these checks since I started RVing in 1972 I have never had an electrical connection failure, but I have sure tightened a lot of them.

mahon1993 · 07-31-2011, 07:06 AM

As in other past posts, the loose transfer switch connections have caused a lot of problems. I have seen near fires caused by loose xfer switch connections. I urge everyone to check all of their 120 volt connections in the xfer switch as well as in the "fuse" box for tightness. Of course make sure you are unplugged, the inverter and generator are off. It would also be a good idea to check the "fuse" box to chassis ground wire at the chassis connection.
Greg

MONGO MAN · 07-31-2011, 07:28 AM

Quote:

Originally Posted by mahon1993

As in other past posts, the loose transfer switch connections have caused a lot of problems. I have seen near fires caused by loose xfer switch connections. I urge everyone to check all of their 120 volt connections in the xfer switch as well as in the "fuse" box for tightness. Of course make sure you are unplugged, the inverter and generator are off. It would also be a good idea to check the "fuse" box to chassis ground wire at the chassis connection.
Greg

It has been a long standing easy practice used by crooked home electricians & RV techs to loosen the neutral - grounded - conductor - cause a lot of heat buildup so that the power panel or transfer switch burns up and nets them a easy, very profitable repair.

wa8yxm · 07-31-2011, 01:26 PM

"The wire came loose from the bus bar"

I am fond of saying that many RVers have a few screws loose.. Imagine how loose that screw must have been (yes, these are the screws I am talking about)

Go through your breaker box and tighten EVERYTHING. NOTE do this while unplugged from shore power and with the Generator OFF.

Needs to be re-checked from time to time as well.

coachmanrvr · 08-22-2011, 11:17 AM

Not saying anything but vibes and or time did this, but I found this in my power cord compartment when trying to coil the cord back up this morning. The top wires are the wires to the RV CB panel and the neutral wire was burned up at the connection. The CB Panel inside also had a loose neutral connection, but the all of the damage occured at the transfer switch. CHECK YOURS NOW!

Quote:

Originally Posted by MONGO MAN

It has been a long standing easy practice used by crooked home electricians & RV techs to loosen the neutral - grounded - conductor - cause a lot of heat buildup so that the power panel or transfer switch burns up and nets them a easy, very profitable repair.

BCooke · 08-22-2011, 11:56 AM

As Norm stated. Part of our service programs in a facilities enviroment is to check electrical connections each year. Reason being is that machinery vibrates or shakes... a lot less than a RV mind you.

ga traveler · 08-22-2011, 12:17 PM

Quote:

Originally Posted by MONGO MAN

It has been a long standing easy practice used by crooked home electricians & RV techs to loosen the neutral - grounded - conductor - cause a lot of heat buildup so that the power panel or transfer switch burns up and nets them a easy, very profitable repair.

I have complained for years about lazy and uncaring techs. I have never known of anyone in the industry loosening screws in changeover boxes. This could easily cost someone their life. My belief is that screws mainly loosen because of low voltage. as voltage drops, amperage (and temp) rises. As anyone who has camped very much knows, campgrounds are famous for low voltage.

EngineerMike · 08-22-2011, 12:28 PM

CoachmanRVr- I don't know what knucklehead decided those rock-hard 90° bends were a good idea, but they are not. Any of those I could replace w/soft 90's would be changed out. Easy to partially break a wire doing that, which break is obscured inside the insulation.

Richard- I sympathize w/the bad roads problem. I frequently drive roads in 3rd world countries like Mexico, & California. Not good for the coach, but the cold Pacifico con limon on the beach is good for the driver. Great advice to do a regular full-dress inspection of all electrical, 120VAC and 12VDC, including chaffing issues which can also cause a fire from rubbed 12V cable.

coachmanrvr · 08-22-2011, 06:32 PM

I agree! I spent about 6 hrs installing a new transfer switch and pulling new wire to replace the toasted ones. 6 gauge neutral and ground and 8 gauge for each leg of the 240. That stuff is tough to work with!

Anyway, I would suggest that everyone add "Check Lugs on the ATS" to their periodic maintenance. (Just to say it...don't check them with power on the coach! GEN OR SHORE!)

Fired it up and checked the gen set and shore power and I am back in business.

Quote:

Originally Posted by EngineerMike

CoachmanRVr- I don't know what knucklehead decided those rock-hard 90° bends were a good idea, but they are not. Any of those I could replace w/soft 90's would be changed out. Easy to partially break a wire doing that, which break is obscured inside the insulation.

Richard- I sympathize w/the bad roads problem. I frequently drive roads in 3rd world countries like Mexico, & California. Not good for the coach, but the cold Pacifico con limon on the beach is good for the driver. Great advice to do a regular full-dress inspection of all electrical, 120VAC and 12VDC, including chaffing issues which can also cause a fire from rubbed 12V cable.

wa8yxm · 08-22-2011, 07:14 PM

I have often joked that many RVers have "A few screws loose". I will not tell you the fact and the reason why.. It is not really a joke.

When this house was still "New" (Under 1 yr old) I had issues with the air conditionrs.. Sometimes one would work, sometimes the other, this on 50 amps and I do not have an EMS so they should both work (or try to) no matter what the power source.

Turns out that many of the screws in the breaker box (Main power distribution box) were lose.. One took a full two and a half turns to become snug, and more to become TIGHT! (I tend to overtighten a bit)

Lost power a few weeks ago to half the coach, twice in one week.

One of the black wires on the Marinco inlet.. over 2 turns to tighten that screw.. I need to re-dress the wire ends and completly re-do the fitting later.

About the only screws that have not come loose, electrically, are the Transfer switch.. Of course the switch failed and was replaced after it left the factory.. Plus I've done some work in that box.. So those screws never got a chance.