Community Forums

chuydog · 06-22-2013, 10:34 AM

We've put on about 2000 miles so far this summer seeing the Country. We normally stop at KOA and need 50 Amp service for our DP.

Sometimes when I hook up to 50 Amp service the transfer switch hums or buzzes and sometimes sounds like an electric motor running. Sometimes it makes no noise at all. I do turn off the breakers at the source before plugging in and everything else is just fine.

Is this normal or do I have a transfer switch that is failing.

Appreciate any comments.

Tom

deandec · 06-22-2013, 10:49 AM

My transfer switch has made some weird noises when it is engaging. I opened the box, cleaned, and tightened the wire connections and the noises disappeared.

My inverter will make a small amount of noise on occasion and is directly adjacent to the transfer switch.

BFlinn181 · 06-22-2013, 10:53 AM

Unplug and check that the connections to the switch are all tight. They can loosen as the wire strands vibrate. Also you might check the contact points in the switch. If they are burnt from arcing, they will just get worse as time goes on. A little emery cloth or a point file (remember them?) might clean them up enough to stop the arcing.

chuydog · 06-22-2013, 11:20 AM

Ah yes, I remember the point file all too well. Even used mom's emery board which was probably a very bad choice way back then.

I'll check the screws going into the transfer switch when we pull out of Sioux Falls in a couple of days. It's nice and quiet now and thanks for the help.

Tom
'04CC Inspire

teddyu · 06-22-2013, 11:55 AM

Can't figure out what could be the source of the noise. Most transfer switches are normally aligned to the shore power position and are enegrized by the generator when the generator is running. JM2¢...

BFlinn181 · 06-22-2013, 12:46 PM

The switch points in my Progressive EMS buzzed until I cleaned them.

Jim_HiTek · 06-22-2013, 01:02 PM

Could be you're hearing the converter buzzing. That noise comes and goes.

chuydog · 06-22-2013, 01:42 PM

Very possible Jim, being mostly deaf in one ear and only selective hearing in the other anything is possible I guess.

Tom

mel s · 06-22-2013, 02:15 PM

Quote:

Originally Posted by chuydog

We've put on about 2000 miles so far this summer seeing the Country. We normally stop at KOA and need 50 Amp service for our DP.

Sometimes when I hook up to 50 Amp service the transfer switch hums or buzzes and sometimes sounds like an electric motor running. Sometimes it makes no noise at all. I do turn off the breakers at the source before plugging in and everything else is just fine.

Is this normal or do I have a transfer switch that is failing.

Appreciate any comments.

Tom

Tom
What coach & transfer switch do you have?
Do you have an inverter/charger/converter?

My transfer switch does not buzz or hum, but my Heart Freedom 20
inverter/charger/converter hums whenever I have shore power, (20A, 30A and/or 50A), and when the generator is running.

BTW, I don't know of any coach that "needs" 50A service.
You may "like/prefer/think you need the benefits of 50A but many folks live comfortably in southwest deserts for weeks/months while boondocking.... with no shore power.

Mel
'96 Safari

Pogo · 06-22-2013, 07:24 PM

The noise is probably the magnetic coil buzzing that is energized. That is not really a concern. It happens fairly frequently and may come and go.
I agree that you should be sure that all wire connections are tight.

chuydog · 06-23-2013, 10:29 AM

That's the plan, Pogo. After we break camp tomorrow I'll check the screws and see if it happens again. Beyond that I am not going to put my fingers anywhere near the guts of this thing even if I knew how to open it up.

Tom

Retired and Happy · 06-23-2013, 12:21 PM

Of course the screws to check would be the ones where the power cords connect inside the case, not the case screws holding the case closed... hence the admonition to power down and disconnect any source of power while checking these screws.

Although if there is sufficient electrical vibration inside, and slightly loose screws outside, there could be some sound outside the case and the case screws might need to be tightened after the internal screws have been tightened.