50 amp transfer switch hums ?

[crown]

ok hooked up power and the transfer switch makes a humming sound  is that normal ? or is it bad ? or maybe need to clean contacts ?
i dont known anything about these help thanks john

[desi arnaz]

  :What tune is it humming?

[Jriddle]

Sounds like it is doing its job.

John

[fe2_o3]

Maybe it doesn't know the words ...Cable

[Sean]

Contactor-based transfer switches will hum when energized.  There is basically an electromagnet inside, so you'll hear a 60hz hum.

-Sean
http://OurOdyssey.BlogSpot.com

[oldmansax]

Sean is right again!

TOM

[Depewtee]

Click here to hear 60hz hum

or copy/paste http://upload.wikimedia.org/wikipedia/commons/a/ab/Mains_hum_60_Hz.ogg into your browser.

Brian S.

[crown]

 hi tryed to open link would not work . ok when i plug in the shore line you hear a loud hum the switch came from the monaco factory
so it is for rv use. in the morning i can get the name & model #  thanks john

[Ed Hackenbruch]

I have had Tinnitus for 40 years so i hear a 60 hz hum or buzz all of the time.

[JackConrad]

John,
   Is Costa Rica power grid 60 or 50 cycle?  What cycle is transfer switch rated for?  Jack

[crown]

 hi jack costa rica is 60 same as usa transfer switch is from usa what might be a proublum is most wireing in costa rica is 2 wire
not 3 wire like usa we do you copper ground poles mine is 6 ft under ground  at first i used a 110 v cord to test outlets i think
i will plug it in to my 30 amp welder cable as that is 3 wire and see if it makes any difference but from what i see heer they do
hum ? thanks john

[Sean]

Perhaps I was not clear: The hum is normal.  Unless you have symptoms of other problems with the ATS I would not worry about it.

-Sean
http://OurOdyssey.BlogSpot.com

[Len Silva]

If the hum is very loud, it may be loose laminations in the relay coil.  Not much you can do except to be sure everything is tight within the box, especially the relay mounting.  It's not dangerous, just a bit annoying sometimes.

[crown]

 ok thanks everyone i went and undid everything  checked cleaned & tightend it all  great the hum is normal so all is ok
thanks john

[Bill B /bus]

I disagree on hum being normal. First bus I used an ATS device (50A) to feed the AC distribution panel. Started to hum upon connection to shore power. Opened input breaker and reclosed hum stopped. As the hum became prevalent every time ATS was energized from shore power I did some thinking and poking. Replaced the contactor/coil assembly on one leg. The cause of the hum was a loose lamination in the core.
Yes a coil maybe energized to close the contactor but a loud hum is unsat. I worked in a big power plant for many years. Noises were tracked to the source and repaired.
These ATS units are in all the high end units and tolerance for loud noise is very low.
Can you make the noise stop by pressing on the coil? Does the noise stop if you apply pressure to the assembly internals? Obviously use a non conductive tool to do this check.

Thank God its not rocket science but only bus stuff that we can eventually fumble our way through.
Bill