Transfer switch delay

phoeg

Senior Member
Joined
Jul 7, 2017
Messages
120
Location
Oklahoma City
Hello, all -

We have a 2016 Thor Hurricane 34F, and I recently had something odd happen in the electrical system that I can't explain. All power from shore, batteries, disappeared, and nothing worked until I disconnected the coach batteries and apparently everything reset itself. I checked the coach batteries, and apart from needing some water they had 12.4 to 13.2V. After reconnecting everything, things are fine, except...

During troubleshooting, I thought there was a problem with the transfer switch, so I tested voltages into the transfer switch from shore power. Power was coming in, but the transfer switch had not connected, thus nothing going out. Suddenly--as I was checking the voltages--the switch kicked in for shore power and the RV came to life. Scared me as it was unexpected. 120V was now coming out of the shore power relay on each side of the circuit. All normal.

The manual and label inside the transfer switch case says there's a 20-30 second delay before kicking over to generator when connected to shore power but we were connecting to straight to shore power. It now seems to take 2-5 minutes for the transfer switch to engage for shore power. That's the new development. The loss of all power to everything and this new behaviour seem too coincidental.

Could there be electronics with the relays and other components that are causing the slow engagement to shore power, i.e. the unit beginning to go bad?

Thanks for your time.

Paul
 
I can think of no fault that will cause all AC and DC power in the coach to simultaneously go away UNLESS the battery disconnect was open OR there was a poor connection on the battery bank which got resolved when you disconnected the batteries to "reset" the issue.

Now, back to the transfer switch: Do you have an EMS or surge protector that could have interrupted voltage to the coach?

Otherwise you could have a poor connection between the power pole and main power center. The ATS connections have a history of being suspect but it could also be the SP cord or any other connection.
 
I can think of no fault that will cause all AC and DC power in the coach to simultaneously go away UNLESS the battery disconnect was open OR there was a poor connection on the battery bank which got resolved when you disconnected the batteries to "reset" the issue.

Now, back to the transfer switch: Do you have an EMS or surge protector that could have interrupted voltage to the coach?

Otherwise you could have a poor connection between the power pole and main power center. The ATS connections have a history of being suspect but it could also be the SP cord or any other connection.

Thanks for the reply. We have it on a surge protector, and in fact, I swapped the main one out for the backup and they both work fine. The pedestal (inside the RV hangar) with the power, and the power cords, are all in excellent condition. The only thing I can think of is that during some of our strange, late-season severe weather in Oklahoma the one power blip we had (while we were down in the tornado shelter) caused the circuits to go funky. But the ice cream in the fridge was still solid, indicating the power hadn't been out long. 🤔

Anyway, all that is resolved, but I'm really concerned about the transfer switch taking an exceptionally long time to engage. It usually it would kick in as soon as the surge protectors engaged. Now I've been wondering if--in the storms--something damaged some electronics in the transfer switch. We have had electronics ruined here by nearby lightning strikes .
 
The issue with the battery at the same time makes this more intriguing? You have explained the issue with SP so it logical that converter may not have been on to provide DC to the 12vdc buss, but the batteries should have. I can't see why or how a storm could affect that. Maybe some Alien Electromagnetic Radiation? But you are in Oklahoma, not Area 51 New Mexico :LOL:

On the ATS, the irony, if it were electrical issues the surge protector should have protected the RV or sacrificed itself. What may be missing is name, make, model and age of the ATS. I would disconnect shorepower and ensure genny is off and not in AGS mode. The check for any odd smells while verifying every screw is tightened to proper torque. Have you tried SP at a different source or with the genny? If so , is it still a 2 - 5 minute delay?

Also, I am assuming the delay you refer to is with the ATS; not the EMS that is inside the RV?

I want to say my ATS with power up almost immediately with SP. However it a delay may 20 - 30 secs for my Southwire Surgeguard to analyze the inbound the power. It will not send to the ATS unless it is confirmed good. At that point the ATS outbound has 120vac, but the coach is still not powered. I have a delay by my EMS before power is supplied to the distribution panel. It is here where you may have issues depending on all of your answers above.

Good luck
 
If the generator is not running, there should be zero effect on the transfer switch as it's default state, if wired correctly, is to pass SP straight through. There are no designed situations where a 2-5 minute delay should be encountered with anything related to the ATS. The DC side of the system should have zero effect on operation of the ATS.

If you have SP coming in, but not out with no generator power, my diagnosis is that the ATS is failing. Could just be dirty or pitted relay contacts.

BTW, what is the make and model of your installed ATS?
 
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Thanks, all for the replies. Our Automatic Transfer Switch (in the coach under the bed) is a Furrion F50-ATS.

In summary:

1) From shore power the surge protectors at the pedestal are working fine: engaging right away and putting out proper voltage on either side of the 220 line into the coach.

2) The cord is fine with 220V (110 each side) entering the coach and ATS.

3) After a few minutes delay, the ATS (inside the coach) 'kerchunks' and connects, sending 110V to the proper places inside the coach. The inverter control panel shows 13.4V from the coach batteries, and everything works fine.

Everything is operating normally save for the mysterious delay in the ATS when initially connecting to shore power. I haven't checked its operation when starting the generator while connected to shore power, though.

As for the lightning...a few years ago we had lighting strike two trees behind our house - 28'-35' away. It didn't directly hit the power line into the house, but the electromagnetic pulse (EMP) was strong enough to ruin 9 electronic devices (TV, hot tub control board, Smoke/CO detector, weather radios, house thermostat, and some other devices near the strike). :oops: Hence my wondering if some EMP had done something to the electronics in the ATS inside the coach.

The mysterious delay with the ATS connecting when initially connecting to shore power is my concern. I'm concerned that it may be a sign the ATS is going. I don't want to be on a trip when it gives up the ghost!
 
Well, I give up. 😄

I just went out and ran the generator, shore power, and transfer switch through their normal paces, and everything worked exactly as it always has. It was perfectly normal. ¯\_(ツ)_/¯


I remembered that more recent than the lighting, we had very strong winds that caused brownouts and power flickers when lines would touch. Those may have funked up the electronics and caused the odd behaviour. But for now everything is fine.

Sorry to use up time here. I just wasn't expecting everything to reset as it did. ¯\_(ツ)_/¯


Paul
 
Thanks, all for the replies. Our Automatic Transfer Switch (in the coach under the bed) is a Furrion F50-ATS.

In summary:

1) From shore power the surge protectors at the pedestal are working fine: engaging right away and putting out proper voltage on either side of the 220 line into the coach.

2) The cord is fine with 220V (110 each side) entering the coach and ATS.

3) After a few minutes delay, the ATS (inside the coach) 'kerchunks' and connects, sending 110V to the proper places inside the coach. The inverter control panel shows 13.4V from the coach batteries, and everything works fine.

Everything is operating normally save for the mysterious delay in the ATS when initially connecting to shore power. I haven't checked its operation when starting the generator while connected to shore power, though.

As for the lightning...a few years ago we had lighting strike two trees behind our house - 28'-35' away. It didn't directly hit the power line into the house, but the electromagnetic pulse (EMP) was strong enough to ruin 9 electronic devices (TV, hot tub control board, Smoke/CO detector, weather radios, house thermostat, and some other devices near the strike). :oops: Hence my wondering if some EMP had done something to the electronics in the ATS inside the coach.

The mysterious delay with the ATS connecting when initially connecting to shore power is my concern. I'm concerned that it may be a sign the ATS is going. I don't want to be on a trip when it gives up the ghost!

Great this is very clear. Your ATS is going or is bad. You never said whether the Generator has the same 2 - 5 minute delay?

The dealer replaced our Southwire ATS when coach was brand new because right after they installed my AGS system they believed some contacts were not properly tightened? I had no idea of the issue as they did all under warranty. I would later check and the ATS I have was only $100. Maybe it would have been $400 labor from Dealer?


Update: I just saw your post #8 as it must have overlap or was sent while I was sending this post.


I glad to see you have run the genny to check. It may have helped to allow the circuitry to reset itself when it worked on genny and the subsequent switch back to SP.

This is a good thread and it helps a lot of people both today and in the future Sooner or later.
 
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Looks like your Furrion has a bit of a different design than Either the PDI or the PowerMax ATS units I have installed. On both of mine, the SP is connected to the the line out through the NC contacts of the relay) so that's its default connection even when no power is applied. They don't do any switching until the second source, a generator, for example is activated and then it has a 20-24 second delay before switching.

OTOH, from reading the manual linked to above, the Furrion has no default input/output connection when there is no power present at either input. When SP is applied, it's supposed to immediately connect the SP to the output. When it detects input power coming in via its secondary input, it's supposed to switch to that secondary input after the 20-23 second delay.

As you reported initially, immediate SP connection was delayed considerably. Since it's now reported to be working correctly, I'm going to classify this as an intermittent failure of the ATS. My inclination, if this were my coach, would be to get a replacement ATS on the way so it's on hand and then replace it as soon as feasible, like before any big trip.

Good luck with it!
 
Looks like your Furrion has a bit of a different design than Either the PDI or the PowerMax ATS units I have installed. On both of mine, the SP is connected to the the line out through the NC contacts of the relay) so that's its default connection even when no power is applied. They don't do any switching until the second source, a generator, for example is activated and then it has a 20-24 second delay before switching.

OTOH, from reading the manual linked to above, the Furrion has no default input/output connection when there is no power present at either input. When SP is applied, it's supposed to immediately connect the SP to the output. When it detects input power coming in via its secondary input, it's supposed to switch to that secondary input after the 20-23 second delay.

As you reported initially, immediate SP connection was delayed considerably. Since it's now reported to be working correctly, I'm going to classify this as an intermittent failure of the ATS. My inclination, if this were my coach, would be to get a replacement ATS on the way so it's on hand and then replace it as soon as feasible, like before any big trip.

Good luck with it!


I agree. It appears the SP connector is getting stuck (maybe when cold) delaying its connection. It may fail sooner or later. I'd replace the ATS and keep the old one as a spare.
 
Page 7 in the link above indicates you can remove the cover (after following the usual safety advice when working with 120V electricity) and observe the action of the contacts.

Perhaps some debris, insects, etc got inside and affected the operation? If no visible crud is present then I agree with the others - get thee a new ATS before it fails completely leaving you stranded.
 
I agree. It appears the SP connector is getting stuck (maybe when cold) delaying its connection. It may fail sooner or later. I'd replace the ATS and keep the old one as a spare.

I had that same thought! Thanks for the confirmation of my thinking...such as my thinking is! :LOL:
 
Great this is very clear. Your ATS is going or is bad. You never said whether the Generator has the same 2 - 5 minute delay?

The dealer replaced our Southwire ATS when coach was brand new because right after they installed my AGS system they believed some contacts were not properly tightened? I had no idea of the issue as they did all under warranty. I would later check and the ATS I have was only $100. Maybe it would have been $400 labor from Dealer?


Update: I just saw your post #8 as it must have overlap or was sent while I was sending this post.


I glad to see you have run the genny to check. It may have helped to allow the circuitry to reset itself when it worked on genny and the subsequent switch back to SP.

This is a good thread and it helps a lot of people both today and in the future Sooner or later.

Well, if it helps someone down the line? Great! I have to say I'm grateful for my shop classes in electricity and my mucking about with amateur radio. It has helped immensely in troubleshooting (as described above). I printed the block diagram of the coach wiring (from the Thor website) and tested every step, putting a green check where things were good, and I would have put a red X where there was a problem. So far the red pen has been unused!

Thanks for all the feedback and confirmation that I was on the right track. Now...time to head out to the coach and run some pink anti-freeze! Ah, winter! :)
 
I agree. It appears the SP connector is getting stuck (maybe when cold) delaying its connection. It may fail sooner or later. I'd replace the ATS and keep the old one as a spare.

Only ATS I have ever seen no working was cooked by lighting strike.

Take cover off and bet shiny inside. If jacked by moisture, can spray some electronics cleaner.

I have brand new one given to me 5 years ago when camp neighbor thought his ATS was shot.

Did he ever just hook up without surge protector?
Try different power source? Took 45 second for my ATS tiokicking at Koa at today's stop. Took 1.5 minutes at other KOA yesterday.
 

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