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Topic: Silent transfer switch? (Read 970 times) previous topic - next topic

Silent transfer switch?

So the oft recommended Progress Dynamics PD52DCS is going through production changes and there's no update on when they'll be available for purchase. I'm looking for alternatives to the original one under my bed. Has anyone purchased one recently that is absolutely silent? I can't stand the hum at night.

I found SOB forum posts about this one but would appreciate a first-hand recommendation.

Thanks much
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Silent transfer switch?

Reply #1
Probably not what you want to do, but I completely eliminated the ATS.  Now we have total silence.  See post linked below and following posts:

Transfer switch questions
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
"It goes without saying..."

Re: Silent transfer switch?

Reply #2
Probably not what you want to do, but I completely eliminated the ATS.  Now we have total silence.  See post linked below and following posts:

Transfer switch questions
I have thought about it and you're right it is something I don't want to do, but if it's my only option for complete silence I'll do it. The Times that we need our generator will be much fewer now that we have solar and I think I'm going to have a DCDC charger put in between the alternator and house batteries so that I can run the living room roof air off the batteries while in transit (with the help of the solar). So I don't know, maybe a manual switch is actually the way to go. Hmmmmm
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Silent transfer switch?

Reply #3
Probably not what you want to do, but I completely eliminated the ATS.  Now we have total silence.  See post linked below and following posts:

Transfer switch questions
Chuck after doing a bit of research on the manual switches, I'm pretty blown away by how much they cost. $300? Wow. I also see some between $30 and $100 of unknown quality. Is there a reason for the wide swing in prices? It's a lot of juice running through that little switch and the last thing I want to do is introduce a safety hazard
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Silent transfer switch?

Reply #4
Sorry,
Not sure what you are talking about.
Humming transfer switch under the bed? Can you post a pic?
Thanks
Frank & Daisy
NO LONGER  "looking for the perfect Foretravel
36' or less non slide preferred."  She has been found and is ours.
2003 U320 36' non slide  Unit 6103
Cummins ISM 450
Allison 4000MH

Re: Silent transfer switch?

Reply #5
Humming transfer switch under the bed? Can you post a pic?
I just parked my rig in storage a few hours ago so I don't have access to it but I'll pirate one of Chuck's pictures from his previous post to give you an idea. If you lift your bed up, there's a panel that you can remove right at the foot of your bed and it'll expose a bunch of wiring. Towards the right side of that area, there are two square boxes stacked on each other that are the ATSs. In my rig, the silver one on top is for the genny/shore power and the black one at the bottom is for the original inverter.

Also, it's possible that the second ATS for your inverter has been removed if your rig his now outfitted with an inverter/charger.


1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Silent transfer switch?

Reply #6
Thanks Elliot
As far as I know mine are located on the drivers side in the large compartment.
Silver box behind little fan
Frank & Daisy
NO LONGER  "looking for the perfect Foretravel
36' or less non slide preferred."  She has been found and is ours.
2003 U320 36' non slide  Unit 6103
Cummins ISM 450
Allison 4000MH

Re: Silent transfer switch?

Reply #7
Thanks Elliot
As far as I know mine are located on the drivers side in the large compartment.
Silver box behind little fan
I'll have to defer to one of the wisemen (and women) around here.  Those are unlike the transfer switches I've seen in my vast experience of Foretravels (about three months). The 99 and 01s I've seen have them under the bed and they basically have 6 wires in and 3 wires out, plus a ground. 
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Silent transfer switch?

Reply #8
Thanks Elliot
As far as I know mine are located on the drivers side in the large compartment.
Silver box behind little fan

That is your main transfer switch that operates with shore and generator as its inputs.

You also have a secondary transfer switch at the foot of the bed that operates with [output of main transfer switch] and inverter as its inputs.

It will be wired something like the attached image in a 2003

Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

Lifetime Escapees' member SKP 82766
Former 1999 30IB Lazy Daze (2000-2004)
Former 2003 U320 (2004-2016)
Former 2017 LTV Unity (2017-2023)
Shopping for our next coach

Re: Silent transfer switch?

Reply #9
Thanks Michelle,
I haven't had any dealings with that one , yet, and have never heard anything humming.
Frank & Daisy
NO LONGER  "looking for the perfect Foretravel
36' or less non slide preferred."  She has been found and is ours.
2003 U320 36' non slide  Unit 6103
Cummins ISM 450
Allison 4000MH

Re: Silent transfer switch?

Reply #10
Hum is eliminated when shore-power contactor relay coil is powered with DC instead of AC. Hum is a natural byproduct of AC relay coils, although most AC coils are pretty quiet.

Re: Silent transfer switch?

Reply #11
Chuck after doing a bit of research on the manual switches, I'm pretty blown away by how much they cost.
Yes, Blue Sea Systems products are pricey.  People who buy them obviously believe they are worth the money.

As Barry says (above) an ATS with DC powered coils is supposed to be silent, and would probably be less expensive.

It's your coach, and it's up to you to decide what you want.
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
"It goes without saying..."

Re: Silent transfer switch?

Reply #12

Chuck, i think the DC powered coil transfer switches are more money.

Amazon.com: Progressive Dynamics PD52V 5200 Series Automatic Transfer Switch...

The Progressive Dynamics PD52DCS with 12v coils is sold out almost everywhere.  It was more $.


Re: Silent transfer switch?

Reply #13
Chuck, the DC powered coil transfer switches are more money.
Yes, but probably less than a $300 manual switch?  I haven't priced them, so I don't know (and don't really care).
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
"It goes without saying..."

Re: Silent transfer switch?

Reply #14
Can anyone confirm their DC powered ATS is truly silent? I keep reading that it "reduces hum" in the descriptions but I want zero hum. Need to be able to hear a mouse fart outside.

Also, if anyone has installed one I'd love to hear where you supplied the DC power from.

Thanks guys
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Silent transfer switch?

Reply #15
Can anyone confirm their DC powered ATS is truly silent?
Try contacting one of these members to get their opinion:

Top Automatic Transfer Switch connector does not engage...

Inverter not powering up

Surge Protection Advice


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
"It goes without saying..."

Re: Silent transfer switch?

Reply #16
Elliott,
I believe the Progressive DC unit create their own DC power inside the box; so you don't need supply it with power.

Just a couple months ago I helped another Foretraveler replace his "AC" progressive transfer switch.  It buzzed when plugged in.  We used some cushioning foam between the box and base to help silence it but it didn't do a lot.

I have a transfer switch that is silent.  When I plug in it does not appear to energize a relay - i.e. no click.  It made me wonder if it was really working right so I verified it isolated the power between the generator and shore and it seems to work correctly.  This is not OEM but a "spare" I pickup at Quartzite about 15 years ago.  About 4 years ago I installed it when redoing my basement.  It seems to me I have seen this same style with many different brand stickers attached to it.  The interior is what seems similar.  Some have a metal box and others are plastic; I don't it matters too much which to pick.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Silent transfer switch?

Reply #17
I have a transfer switch that is silent.  When I plug in it does not appear to energize a relay - i.e. no click.
John,

That is an interesting ATS.  From the photo it doesn't appear to have any moving parts.  And you report no sound of contacts clicking, so one might wonder how exactly it manages the transfer of power from one circuit to the other.

One of our electronic gurus will undoubtedly clear up the mystery.
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
"It goes without saying..."

Re: Silent transfer switch?

Reply #18
I installed a Bluesea manual switch, silent
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Silent transfer switch?

Reply #19
All I see in the photo is a terminal strip with three feeds coming in and going out the back of the box to "somewhere"?  Not sure what the blue leads are for as they don't appear to be connected to anything.

More photos or info is needed.....................\
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Silent transfer switch?

Reply #20

There are two relays under the terminal strips.
The blue wires appear to be for a 4th switched wire (AUX N2) - typically not used.
There appears to be a bridge rectifier to create a (poor quality) DC from the AC.  There's another quad thing in there with 4 wires going to it that I think generates a delay for the generator switch over.  No power conditioning whatsoever.
I took the best picture I could with out un-wiring the thing.

This seems to be a very similar design:
Amazon.com: WFCO T57 50 Amp Transfer Switch: Automotive

On iRV2 this discussion says the Parallax ATS 5070 is no longer available:  ATS / automatic transfer switch - iRV2 Forums

They say the Parallax ATS503 should replace it but the ATS501 looks more like a direct replacement to me:
Amazon.com: Parallax Power Supply  (ATS501 120/240 Volt 50 Amp Transfer...

Since I don't have any of these other replacement units, I really can't endorse them.  Maybe someone else has tried one of them?
BTW, I do think a metal box is much safer if the relays or wiring catch fire!!

John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Silent transfer switch?

Reply #21
John
What are the wires connected to that go out the back of the J-box? I see what appears to be a couple of solid state (crydom maybe?) relays under the terminal strip. The actual transfer switch must be behind the J-Box?

Thanks..
Edit........
After looking more closely at the links you provided, it appears all the major parts are behind the divider panel in the j-box. I thought the wires were leaving the box, out the back side.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Silent transfer switch?

Reply #22
I decided to go with the guaranteed silent option and bought a manual transfer switch. I was able to get the Blue Sea 9093 new off eBay for $235 so I saved a bit. Once I get my DC2DC charger installed the switch will spend most of it's life set to shore power.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Silent transfer switch?

Reply #23
KISS is GOOD.

Manual is GOOD.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Silent transfer switch?

Reply #24
This "$10,000 in the first year of ownership" rule you guys came up with is starting to look optimistic
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.