If you hear a buzzing sound, don't ignore it

[mikeaubry]

Hello All,

Just a heads up, regarding hearing buzzing noises or weird sounds.  

We purchased our 2009 Pace Arrow used a few years ago and went through the process of learning how things worked - as we went along.

As with most new things, there was the normal amount of different kinds of noises, rattles, and squeaks. We mostly wrote them off as normal for a rig that was not brand new.  Most of the noises were inconsequential, until we ran across the "buzzing behind the wall".

We arrived at the campground and went through the normal hook up process. Everything went along as normal, except a few hours later the faint buzzing noise from behind the wall under the TV, was abnormally louder than it ever had been before.

This signal that it was time to further investigate the source of the noise. After removing the access panel, we found a big gray metal box and a bunch of wiring going into it, and coming out of it.  It was labeled "Transfer Switch", and it was clearly the source of the loud buzzing. And, now that we had the box out from the cabinet, there was a weird smell too.

I'm a pretty handy guy, and not afraid of doing my own repairs - so, after digging through all the manuals and paperwork that came with the rig, and finding the one that matched the Transfer Switch - I read all about it. What it does? Installation instructions? etc...

I switched off the power at the post, and removed the box from the mounting location. Then removed the metal cover. 

The photos attached shows what I found inside the Transfer Switch Box. 

As you can see, the insulation was melting from the wires. The "buzzing noise" was due to the Lugs (screws that hold the wire in place) NOT being tightened down with the correct amount of force. The relays (switches) that the wires were connected to are a vital part in the electrical system. I found a new "Transfer Switch" with the exact same part number at an RV dealer about an hour away, and purchased it that day. Replacing it was relatively easy, and I also purchased a torque driver to assure that the lugs were tightened down the specified amount.

We now have a new line item to add to the annual check up list for the rig.

We were fortunate that nothing worse happened, and this is a lesson learned that we thought would be good to share.

Don't ignore those weird buzzing noises.

 

 

[hermanmullins]

Mike, 

If it hasn't been said before, Welcome to the Forum.

Good catch, it could have been much worse. Glad you were able to get a replacement and that you are back on the road.

Herman

[jleamont]

Mike, glad you caught that before it turned catastrophic. This is a common failure point due to lack of maintenance. Here is one of MANY posts on it;

 

 

[wolfe10]

As Joe said, the screws in the ATS and 120 VAC breaker box need to be retorqued as part of an annual coach service.

As they get loose, that creates resistance which creates heat which loosens the connection more.......................

[elkhartjim]

You mentioned you turned the power off at the pedestal; I also recommend turning the automatic generator start off if equipped and confirm the inverter is turned off.  

 

[richard5933]

I also see a twist-on wire nut in the photo on the ground wires. Those have a tendency to loosen with vibration, so it would be wise to make sure that any wire nuts you see are tight.

[manholt]

Jim S. Good point...Joe L. took care of mine in PA.   Thanks Joe!

[rayin]

On 10/4/2019 at 3:44 PM, richard5933 said:

I also see a twist-on wire nut in the photo on the ground wires. Those have a tendency to loosen with vibration, so it would be wise to make sure that any wire nuts you see are tight.

If using a wire nut this is the one I use:

[richard5933]

8 minutes ago, RayIN said:

If using a wire nut this is the one I use:

What are those called? Where do you find them? They definitely look like something that should be in the emergency repair kit.

[rayin]

Set screw wire nut/connector, available at any electrical supply store. Made by Ideal. I think I bought some last at an ACE hardware store though.

I first saw them when one of our maintenance men was performing some electrical work on my industrial wastewater treatment plant. I asked, and he gave me a few to try at home.