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Topic: Need A Replacement ATS Recommendation (Read 974 times) previous topic - next topic

Need A Replacement ATS Recommendation

Our ATS has been "humming" for a long time, but has otherwise worked fine in all situations.  Today, I disconnected from our shore power plug to reposition coach so I could mow around it.  While "off the cord" I had the generator going to power residential fridge.  When I was done mowing, I re-parked coach and plugged back in to our 50 AMP outlet.  The EMS-50 clicked and sent power down the cord, but the ATS did not accept the shore line input.  Tried unplugging cord, and reconnecting several times before the power finally came on in the coach.  Acted like something was "sticking" in the transfer box.  I'm thinking it is time for a new ATS, while I can change it in the relative comfort of our driveway rather than while on a trip out in the boonies.

Yes (before you ask), I know about the EMS-50 "time delay" before the power comes on line.  And yes, I have always followed the "best practice" procedure of shutting off all loads before switching either way between GEN and shore power.

Searching the Forum I found several (older) references to the LYGHT POWER (By ESCO) LPT50BRD, but nothing very recent.  Is this still the most recommended ATS, or are there now better alternatives?
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: Need A Replacement ATS Recommendation

Reply #2 –
After I cleaned the dust from my Lyght ATS, it became dead quiet, no issue since.     

Re: Need A Replacement ATS Recommendation

Reply #3 –
Chuck,

If still original equipment the ATS-100 use two Furnas contactors. Replacement contacts are called "contactor kits" and are packaged for one pole, so the two contactors use 6 packages. ATS-100 contactor kits are part # 75BE42.  We have been getting them from these people but you may find them cheaper if you hunt http://www.electricalcontactkits.com/contact_kits.asp?Eck=FN75BE42&Ref=furnas  A good cleaning with contact cleaner and new contacts will most likely help your humming.

 If the contactor unit itself gets burnt up you can use your metal case and take the old Furnas contactors out and to an electrical supply house for a replacement.  There will  be a sticker on the top that will have a part # and rating so you may be able to find a replacement  on the net. I think Furnas was asorbed be Siemens so unless it is NOS you will probally be replacing it with a Siemens. Here is a link over to Barry's site for what you may encounter if a complete replacement is needed.  Replacing a Transfer Relay

Pamela & Mike

Pamela & Mike 97 U 320

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

Re: Need A Replacement ATS Recommendation

Reply #4 –
Thanks Mike.

So the way I understand it, these ATS boxes contain several switches called "contactors" wired together.  Each individual "contactor" has several "contract" sets, which are activated by coils.  Dirty or worn contacts can cause the commonly griped about "hum".

The "hum" has not been a big concern for us.  Both of us have "age-related" hearing degradation, which is sometimes a blessing.  What DOES concern me is when the ATS fails to do it's job.  This recent incident was the first time this has happened since we've owned the coach.  I believe we do still have the ATS-100, but need to verify that fact.

I get the impression you are Old School "Repair it, if possible", rather than "Throw it away and buy a new one".  I like that kind of thinking, BUT, sometimes new technology IS better.  For instance, in my (so far limited) research, I see reference to "DC powered coils" in the new ATS units, which are supposedly quieter.  There may be other benefits of which I am not aware...

So, in this case, is it better to upgrade to a new device, or (hopefully) rebuild the old one to "like new"?  Cost, in this case, is not a factor in the decision.  I DO seek long-term reliability and trouble-free performance.

Thanks for all the good input!
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: Need A Replacement ATS Recommendation

Reply #6 –
Peter, Thanks for the link.

Further online study reveals two of the selling points of the Lyght Power (by ESCO) model LPT50BRD are the use of DC powered coils AND the fact that shore power is the default mode.  This reduces the chance of any noise because the coils are not in use unless you are on generator power.  This is the exact opposite of our current ATS, and the reason we have the buzzing when we are plugged in (which is most of the time).

Heck, when we run the generator, it is usually because we need the air conditioning, and even if the ATS did make a little noise in that situation we would't be able to hear it over all the other racket!

Sounds like a good product from what I have read so far!  Still in "research mode"...
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: Need A Replacement ATS Recommendation

Reply #7 –
At least open the transfer switch to see if it something simple.  And we agree with Pamela & Mike and have also changed out our contactor 'points', which is a simple job.  You may find that the ATS-100 is a strong unit and has some features that the new ones don't have.

Re: Need A Replacement ATS Recommendation

Reply #8 –
Quote from: Mogan David –
ATS503
@Mogan David - I'm not ignoring your recommendation.  I have sent a email request to Randy at Best Converter for info on the ATS503.  I have purchased a charger/converter from him in the past, and value his input. 
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: Need A Replacement ATS Recommendation

Reply #9 –
Chuck,

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 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.

Pamela & Mike
Pamela & Mike 97 U 320

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

Re: Need A Replacement ATS Recommendation

Reply #10 –
Switched to the lpt50brd, went from hum to no hum.

Lpt50brd can come in two sizes. Verify the size you need. In ours it's a tight fit.

My original transfer switch had input on one side, outputs on opposite side. Lpt50brd has input and outputs on same side. May require changing some wiring, a pain with this large wire.
Mike & Molly Patronick
2001 U320 40'
2011 Forester

Re: Need A Replacement ATS Recommendation

Reply #11 –
@Barry & Cindy:  At your urging, I will open up the box and poke around (with a non-conductive stick), before I open my wallet.

@morninghill:  Thanks for the tips!  I will take measurements and determine available room whilst I'm poking around.
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: Need A Replacement ATS Recommendation

Reply #12 –
I will close out this thread with a happy ending (or at least a less expensive one involving less work for you-know-who).  It is now clear that I should have done a little more investigating before I "opened mouth and inserted foot".

After seeing my initial post comments, which DID generate excellent leads/tips/advice from the group, I heard from the PO.  He said he changed out the ATS soon after he purchased the coach in 2010!  Searching back through the maintenance records, sure enough, I found the notation on the replacement.  Apparently our coach originally had the ATS-100, but is now equipped with a Progressive Dynamics Model PD52.  This is a excellent ATS - there would be no real benefit to replacing it at this time, as long as it is functioning correctly.

Taking Barry's advice, I opened the ATS cover and checked the innards.  There is absolutely no evidence of over-heating, burned wires, loose connections, or any other problem.  I then proceeded (over the course of the day) to run the ATS through 3 complete cycles of operation.  I shut down all loads, cut the shore power at the breakers, started the generator and then restarted the loads (both A/C units).  Then, an hour later, I reversed the procedure.  Did that 3 times.  The ATS functioned perfectly each time.

I still have no explanation for the incident that prompted this thread, but I'm going to discount it for now.  Other than the HUM, which is still there in both generator and shore power mode, the ATS seems fine.  What I AM going to do is seriously consider the option often suggested by Brett Wolfe: a manual switch.  When I look at the deliberate way I ALWAYS handle switching between shore power and generator, I realize the ATS is simply unnecessary.  Utilizing a simple, rugged, reliable and QUIET switch to enable the selection of power source sounds very KISS to me!
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: Need A Replacement ATS Recommendation

Reply #13 –
Chuck,

The manual switch  I suggested is to replace the BATTERY ISOLATOR (i.e. 12 VDC system, not 120 VAC).

Yes, there are manual switches to replace an ATS, but ATS's are pretty good at what they do.

Here is a manual transfer switch:
BLUE SEA SYSTEMS AC Rotary Source Selector Switches | West Marine
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: Need A Replacement ATS Recommendation

Reply #14 –
Oh.  As Emily Litella (Gilda Radner) often said, "Never mind."

Guess I should have gone back and read your posts...everybody forget everything I said and go about your business.
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: Need A Replacement ATS Recommendation

Reply #15 –
Quote from: wolfe10 –
Here is a manual transfer switch:
BLUE SEA SYSTEMS AC Rotary Source Selector Switches | West Marine
Thanks, Brett.  That is exactly what I had in mind!  I might just try it out - seems pretty fool-proof (which, in my case, is a good thing).
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"