Auto transfer Switch stuck. fixed now but need to know cause

[nana25k]

Pulled in to park yesterday and plugged the MH in. No power to coach. Flipped the breaker on the pole it came on then went off. Flipped again nothing, Nada, zip. Everything 12 volt worked as did all AC on the invertor. Everything worked on genset as well.

Park came and checked the power at pole and changed the plug. They even metered our cord.

We have a Todd ATS. Ron crawled in this morning and once the cover was off proceeded to check things out. There are two buttons, one on each relay. They were both flush. He pushed on them. They both went in. Turned on power and on it came. One of the buttons remained in the other one popped out some.

So appears to us that the relay was stuck.

Question is what may have caused this and what should we be looking for?

On Wed evening we were plugged in to shore power with no issues. On Thur we used the Genset briefly while blacktop camping. We did drive thru several days of rain and we had some pretty hard downpours

Could moisture be a culprit?? We assume this is original equipment so its 15 years old

[sundancer268]

For your information TODD Engineering is out of business as I found out several year ago. You are not out of luck though, as the relays were made by someone else and you should be able to replace them. I do not remember what brand the relay is though, if it is Square D, you should be able to even rebuild it with a factory rebuild kit depending on how handy you are. Good luck, Ed

[AFchap]

On many it would be sticking contact points, the result of wear and tear, exacerbated by allowing power changeover from generator to shore & vice versa while heavy power is being used. The ATS always defaults to generator power, and when it is not available and it senses shore power, it will switch over. When that happens under a heavy power load, it arcs between the contact points and they get burned & worn, and then they tend to stick together So then when you plug into shore power, the ATS cannot switch over. I had one that I could smack hard a coupke of times with my fist and I would hear it switch over. A rubber mallet would also do the trick on mine. When changing power sources, all power loads than can be turned off should be turned off.

[StarDreamers.us]

Have not heard that method of repair in a while. Rubber mallet method. I guess I need to find a rubber mallet. Good idea.

 

Safe Travels!

[Kirk W]

 

So appears to us that the relay was stuck.

Question is what may have caused this and what should we be looking for?

It is quite possible that the transfer device was stuck and that isn't an uncommon symptom when one has problems. They do fail in time and the most common cause is that the contacts get burned and begin to stick, much as though they were welded. It is also quite possible that you had some type of mechanical bind which could be due to wear on the moving parts or some bit of dust or dirt in the system. An ATS is designed to have the genset as the preferred source if both sources are available. When you disconnect shore power the contacts normally shift to the genset position even if there is no power there and shift back when you connect shore power once more, so that is the way they most commonly fail. Often when on sticks a sharp rap with a rubber mallet will free it and the contacts shift and may then work for an extended period. If yours should do this again, I'd try the mallet as a first, quick fix. But if you need to do this very often it is an indication that it is nearing the terminal stage of life and that you should probably be considering replacing it before you loose all ability to transfer.

 

It is also important to remember that you should always turn off all of the larger electrical loads when you shift from genset to shore power or back again. The reason is that there will always be a mismatch of the electric phase relationship between the two and so a surge of power will take place and each time that happens it puts a lot of heat on the contacts as well as the fact that shifting sources while under load will cause arcing that will in time destroy the contacts.

[Yarome]

It is also important to remember that you should always turn off all of the larger electrical loads when you shift from genset to shore power or back again.

 

X2. Just the age of it is probably a factor, but even on a new ATS heavy arching can lead to a whole lot of trouble.

[Yarome]

... Just to add... if you don't have one yet.. duct tape and a rubber mallet are the two most important things to have in your tool box.

[nana25k]

... Just to add... if you don't have one yet.. duct tape and a rubber mallet are the two most important things to have in your tool box.

Oh believe me we just started our 9th year on the road Ron has all those types of things

 

We always have all loads off when we switch over. Usually the refer is on gas from coming off the road. Possible the only thing on is the water heater. Our dash air and heater works so well we've never even in 90 temps needed to run the genset for house furnace or a\c.

However since we are the coach's 3rd owner we don't know what previous owners have done in the past.

I'm thinking that we may just replace the ATS in a few weeks when we are in PA for some extended down time. We have my brothers huge commercial garage so while we are doing the regular service and new shocks it will be a good time to do this too. It is as I said a 2000 era.

Any recommendation on brand to buy??

[Yarome]

I'm thinking that we may just replace the ATS in a few weeks when we are in PA for some extended down time.

 

Hey Nana. Unless your experiencing some issues with it, I would probably let it go. Maybe eyeball it when you're getting the dust bunnies off the PD board, but unless there are scortch marks or someone has already let the blue smoke of it you should be fine. It's pretty simple, but a new one could set you back $150 or so. I would just keep running it and just take a little more care if it's a concern... Ie., unplugging shore power before starting up your genset and vica versa. That would just be a precaution and isn't really necessary if the heavy loads are off, but if it gives you a little more peace of mind it just takes a sec, right.

[nana25k]

Seems that we always experience these types of issues at the most inconvient time. If Ron's having a not great health day then we are at the mercy of finding a repair person and a part. So far our experience with our refer electronics caused 4 different repair people and the first 3 ended up making matters worse because in the end they were just rejory rigging an already jory rigged mess. (And its still cranky, we had to run a distance the other day with propane off because we were going thru the Hampton Roads tunnel. The darn thing wouldn't completely shut off. Kept beeping telling us no ac\ no flame. Drove me crazy for an hour til we could stop and turn it back on!!!

That's why we may just replace the ATS while we have free labor

[Yarome]

That's why we may just replace the ATS while we have free labor

 

If it was just the one time, then I would still hold off on it, but certainly not going to hurt anything to take advantage of free labor. I wouldn't have any qualms with picking up a Progressive Dynamics. I haven't presonally used one of their ATS's, but I've dealt with the company enough to have confidence in their products. Hopefully someone with first hand experience will chime in.

[oldjohnt]

I agree with the gents the contacts are burned and carboned which can lead to sticking and hanging in the closed position. The hardest thing on contacts is operating them under load, especially inductive (motors), as the current surge is greater then normal. When the contacts are closed theres not near as much stress/heat on them as opening or closing subject to high current high heat producing arcing. In cases where the contactors are in sight a light cleaning/buffing to remove carbon and smooth them down may help, but once their coating is gone they are likely to fail, consider such ONLY a temporary band aid fix.

 

John T

[oldjohnt]

Yo Bill, I have lightly cleaned/buffed/polished (call it smoothed) relay contacts which always helped??? I had some that NEVER stuck again following that????? But whose to say what material or how good or how cheap the coatings may be or how much material was removed, so I see how your comment may be right on the mark with many ( I may have had super quality or super junky brands lol) . I think one problem may be people get too aggressive and FILE AWAY too much actual silver leaving steel or what other raw material AND AFTER THAT FAILURE SOON FOLLOWS.

 

Oh well if his are badly burned or pitted they may well need replaced regardless, like I say what I did was at best a band aid fix.

 

Keep safe yall

 

John T

[John Laninga]

Monaco installed an IOTA Transfer Switch in my coach. They were known to start fires (they used undersized internal wiring, and installed it in a plastic box). I believe they are now out of business. So, like many Monaco owners, changed it to an Elkhart ES50M-65 transfer switch. It uses industrial relays and is ultra reliable. This unit is available from Amazon.

 

BUT, it does have one problem. The relays are normally open when on generator, so they are always energized when on shore power. This isn't a problem except if you're anal like me... the hum bugs me. I can minimize the hum by turning power off and on again. Elkhart realized this, and brought out the LPT50BRD switch. This has the contacts Normally closed on shore power, so no hum. Works the same, just quieter. And it is cheaper on eBay.

 

So just a suggestion of something you can look for when replacing yours, based on user experience. I would have bought the Progressive (I have their EMS) but they didn't have the switch out when I bought mine from Elkhart.

 

== John

[jpatrickc]

I have noticed the hum when on shore power. Has anyone reversed the inputs so that the shore power is on the NC contacts and the generator is on the NO contacts? You would never notice the hum with the generator running. The only think I can think of that this would do is that it would give the generator priority if you had both shore power and the generator running.

 

Pat

[John Laninga]

I have noticed the hum when on shore power. Has anyone reversed the inputs so that the shore power is on the NC contacts and the generator is on the NO contacts? You would never notice the hum with the generator running. The only think I can think of that this would do is that it would give the generator priority if you had both shore power and the generator running.

 

Pat

 

That sounds interesting but I notice in the service and trouble shooting manual that the two relays have different part numbers. So presumably you can't do this, but I will call the factory and ask.

 

John

[AFchap]

I have noticed the hum when on shore power. Has anyone reversed the inputs so that the shore power is on the NC contacts and the generator is on the NO contacts? You would never notice the hum with the generator running. The only think I can think of that this would do is that it would give the generator priority if you had both shore power and the generator running.

In those I am aware of, the generator is already the default power source. Shore power kicks in ONLY if generator is shut down.