Maintenance Reminder - Tighten Electrical Connections

[digNbubbs]

Just a reminder to check your electrical connections periodically. Last night I heard a buzz in the breaker panel when the A/C compressor was kicking on. Reminded me that it had been about a year since my last tightening session.

The picture below shows the box and my notes on the different connectors. It was odd how the "groups" had about the same amount of "looseness". The amount of looseness below is noted in averages for that group of connectors.

Of note is one of the wires in the neutral bus bar that looks a little charred. This happened last year when I found a bunch of the connections loose. I think I will add to my maintenance notes to check this twice a year now. (click for full-sized image)




--kev

[Bob&AnnaMari]

Kev,
Thanks for the reminder. I just tightened the screws on my surge protector due to the experience of another fellow on these forums. Now I will add these other connectors to the maintenance schedule.
Bob Stokesbary

[chiefdave]

Thanks for the information. Just finished checking my 2007 Knight 50 AMP distribution panel and found several in each area that needed adjustment. Appreciate your reminder. Would not be a bad idea to post this thread on all motorhome forums as we all drive the same roads.

[Ron Postma]

The reason groups of wires were the same is the thermal mass of the buss bars. The looseness is probably from thermal cycling. They get cold they shrink, they get hot they expand. Our RV's get colder than our houses. The manufactures say if you torque the screws to their specs. they should not loosen up. But who has the proper torque wrench. Be careful not to over-tighten them they are soft and you can easily strip or break them. The suggestion of adding this to your yearly maintenance is a great idea. Don't forget to also check the transfer switch.

[digNbubbs]

Thanks Ron. That makes an awful lot of sense about the thermal mass of the buss bars.

If my connections were torqued to spec before leaving the factory, I will have to completely disagree with the manufacturers that claim that they will not loosen. I would have to assume that either Monaco did not torque properly, or they will loosen no matter what. Regardless, I will be checking more often

Thanks again for the information. Glad when something makes sense.

--kev

[wa8yxm]

I am forever telling folks that we RVers often have a few screws loose...... The kind you tighten with a #2 Square or Robertson bit.

Often, those are in the breaker box, epically on new rigs

here is why.

The technician at the factory tightens them down good. I mean, he really is doing it right, but copper is somewhat "Mallable" (means you can hammer it flat) and as the rig gets hot, and cool, and as it bounces down the road, teh wires become less and less round and more and more flat. and you need to re-tighten.

[Ron Postma]

Copper has a high expansion coefficient meaning the amount of change in size vs temp. Aluminum has a higher one. They used to build houses with aluminum wiring around here but the burned down too often.

[gonzo]

This is soooooo important to do.

We previously owned a 2003 Trail Cruiser by R-Vision. I was sitting outside in the evening and noticed that my awning lights are flickering once in a while. I also heard that beep from the microwave when you turn the 120V on. This continues for a while and I thought that there must be a power problem on the campground since a nasty thunderstorm just past. I checked with the camper next to me and he told me that he does not have any problems.

This made me nervous. I check my shore power connection which was OK. I now went inside to the electrical panel and heard the buzzing. I ran outside to disconnect the power and opened the panel. I WAS SHOCKED. 2 of the neutral came loose and arced. It go to hot inside the panel the the wiring was starting to burn. The neutral bar started to melt. There was ashes on the bottom of the panel. I WAS SO LUCKY I found this.

I did a quick emergency repair and went to the dealer the week after. R-Vision first refused warranty because the trailer was out of warranty for 6 month. But after a quick call by myself which ended in "I will contact UL/CSA and file a complaint". 1 hour later the dealer called me and told me R-Vision pay to have the electrical box exchanged and the ENTIRE TRAILER will be wired new. At the end R-vision did a lot more than I asked for.

[digNbubbs]

Thanks for the backup on that gonzo! Glad to hear you caught it before big problems occurred.

I just found another thing this piece of maintenance solved. Shortly before I did the tightening, we were experiencing issues with our fridge on AC power. Some mornings we would get up to a too-warm fridge. We would switch over to LP and it would get cold again.

After tightening the connections, I switched the fridge over to AC power. it has run perfect ever since. I think it is possible that the connection for the fridge was being affected by the loose connections. I have no empirical evidence to prove this, just the above series of events. Works for me tho



--kev

[wa8yxm]

Quote:

Originally Posted by Ron Postma Copper has a high expansion coefficient meaning the amount of change in size vs temp. Aluminum has a higher one. They used to build houses with aluminum wiring around here but the burned down too often.

Thanks Ron, that is what part of what I was trying to say.

The moral is tighten those loose screws on occasion.

[keypontrikin]

This place is a real education! Thank you all for sharing so much.

Now gotta figure how to do this safely. Just turning off the battery switch enough or disconnect them completely? A little guidance here would be a big help.

Bob

[digNbubbs]

Quote:

Originally Posted by keypontrikin This place is a real education! Thank you all for sharing so much. Now gotta figure how to do this safely. Just turning off the battery switch enough or disconnect them completely? A little guidance here would be a big help. Bob

Hi Bob - the safest way to do this is with a voltmeter. Don't touch a thing until you test the voltage.

If you unplug from shore power, turn off the inverter, and disconnect the house batteries, you should be fine. Be sure to test and retest before touching

--kev

[wa8yxm]

I have posted many times that we RVers tend to have a few screws loose. And the screws in the breaker box are very often the very screws I am talking about.

(And you thought I ment mental as opposed to metal screws)

[gonzo]

I better don't let my wife see this one sice I was the one that had those screws loose!!