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ATS hum

I've tried insulating the sound from the ATS under the bed with limited success and am considering re-locating it and the surge protector to the utility bay to that area  where the cord and hose is normally stowed.  After studying the electrical diagram, it doesn't look like it would take an electrical genius.  Has anyone done this?
2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8

Re: ATS hum

Reply #1 –
Sven,

The A/C coils do cause some humming because that is just there nature. Was told by an old timer that worked on my crew that the hum was caused because the electric molecules are square when they leave the generator, as they travel down the round wire the corners get knocked off and thus you have a hum.  Now back on task.  If you go with a new style ATS with a D/C coil that should stop your hum and will work just fine as there are others that have swapped to a D/C system and are pleased. You can also change out to a manual switch which several have done with great success.  Doing it this way you don't have as big of a job of moving wiring.

Will your plan work? Yes, your big thing is going to be pulling wire and finding a place to mount your ATS that is out of the way but still accessible.

Pamela & Mike

Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: ATS hum

Reply #2 –
Quote from: Pamela & Mike –
  You can also change out to a manual switch which several have done with great success.
Not only the hum, but we've been parked next to some coaches where, for some reason, the gen set fired in the middle of the night!
Should we lose power, big deal, the Dometic switches to propane, that's all I care about, I hate warm beer!  ^.^d
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: ATS hum

Reply #3 –
You're not the only ones that have been bugged by the hum...it is a common complaint.

30 amp transfer switch HUMMING!
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: ATS hum

Reply #4 –
The best solution to a humming transfer box under the bed is to replace the trasfer switch with one that uses DC relays . The old ones were used AC powered relays and they do hum as they get older.

Jim
Jim Frerichs
2002 U320 42'

Re: ATS hum

Reply #5 –
Make sure all the connections are tight.
Not much else except change the switch.
John Duld
1995 U320C SE 40'

Re: ATS hum

Reply #6 –
And that the contacts are clean and make solid contact.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: ATS hum

Reply #7 –
We have had a couple of different under bed ATSs that have hummed.  Some louder than others.  Last week powered down and removed the contacts and sprayed with computer air can both contacts.  There was quite a bit of residue/dust particles that were blown out.  This helped for a while.  Now the hum comes and goes.  Have thought about going to a marine type switch as well as the DC type.  I would be most interested in the DC type to keep the Automatic function.  That being said, when we installed our Magnum 2812 I was told that we could eliminate the ATS under the bed if we increased the size of one wire from the Inverter/converter to the breaker box.  Haven't done that either.  :D
Scott & Carol Seibert
2001 42' double slide U320 - Sold
Previous - 2002 36' U320

Re: ATS hum

Reply #8 –
You could just try changing the contactor in the ATS, sounds as if the "shading coils" are loose or broken. These are the small rings around the laminated iron core of the contactor and are used to minimize the vibration of an AC contactor by reducing eddy currents in the iron core.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: ATS hum

Reply #9 –
Quote from: Pamela & Mike –
Sven,

The A/C coils do cause some humming because that is just there nature. Was told by an old timer that worked on my crew that the hum was caused because the electric molecules are square when they leave the generator, as they travel down the round wire the corners get knocked off and thus you have a hum.  Now back on task.  If you go with a new style ATS with a D/C coil that should stop your hum and will work just fine as there are others that have swapped to a D/C system and are pleased. You can also change out to a manual switch which several have done with great success.  Doing it this way you don't have as big of a job of moving wiring.

Will your plan work? Yes, your big thing is going to be pulling wire and finding a place to mount your ATS that is out of the way but still accessible.

Pamela & Mike


I would have to look into how much a new style ATC would cost.  As far as the wiring is concerned, it is already there.  The end that is now attached to the incoming side of the ATC would go to the breaker panel and I would attach the relocated ATC to the other end, which is presently at the shore power connection.  The only additional wiring would be from the shore connection to the relocated surge protector (still connected to  the ATC) which would be next to the utility bay.  I need to know if my reasoning is faulty.
2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8

Re: ATS hum

Reply #10 –
Quote from: Carol & Scott –
when we installed our Magnum 2812 I was told that we could eliminate the ATS under the bed if we increased the size of one wire from the Inverter/converter to the breaker box.
Scott,
 
I'm very interested. If you could find your notes, I would like to make that change. Which of my two ATS boxes do I remove?
 
I am going to install my EMS and one less box in that location would make it a bit easier!
 
Thanks,
 
Trent
Trent and Jean Eyler
2000  U295  4003  WTFE  ISC  350
Build#5603 MC#17385

Re: ATS hum

Reply #11 –
Trent -

Just sent  you a copy of some emails exchanged between Magnum and me a couple of years ago.

Scott & Carol Seibert
2001 42' double slide U320 - Sold
Previous - 2002 36' U320

Re: ATS hum

Reply #12 –
Scott,
 
I was talking to them yesterday on a different issue.
 
Instead of holding, I chose the option to get a call back; that happened within 15 minutes. Second time I have talked to their Tech Support; they seem very knowledgeable about their products.
 
Thanks for the information,

Trent
Trent and Jean Eyler
2000  U295  4003  WTFE  ISC  350
Build#5603 MC#17385