MADAY! My Auto Power Transfer Switched fried

[Barney]

Hello Friends,

We became Full-Timers 11 days ago and last night we lost all AC power while hooked up in a park near Ft Smith Arkansas( 50 amp).
We've been here a week and it's hot and we been running AC's etc but no issues or tripped breakers. When everything went dead I first
checked the shore power connection, ok breaker not tripped power still hot at the post.
Then, when I opened the 3rd bay from the front, passenger side) got a cloud of smoke and that burnt wiring aroma we all love.
On the left wall of my 2000 Country Coach is the ATS ( auto power transfer switch) the box was very,very warm. I shut everything
off. Today, I removed the small refrigerator that was blocking my access to investigate.
I found a Todd Engineering Power Switch Model PS262S, Inside I could see several wires burnt to a crisp and bare copper exposed.
Oh BOY!, If you've been down this road and can offer any advice I'd appreciate it. I assume I'll need to find a repair tech/shop and get
it replaced. I am concerned with availability of a replacement that will be compatible with the rest of the system.
Please tell me what you know on this subject, I think we'll move to a motel until I can sort things out.

Thanks,

Barney

[gmcbuffalo]

Barney it looks like that unit has been replaced by the following

<tbody>

Section #2 A... 50 AMP Model.... 2 or 3 Wire For Marine or RV Applications


AUTOMATIC SWITCHOVER: Switch from power cord to generator simply by starting generator!


A... 17-REL36050 Heavy Duty Relay Overview
B... Electrical Overview - 17-REL36050



http://cmsquick.com/prod_17_ES50m65N_small.jpg (http://cmsquick.com/prod_17_ES50m65N.jpg)Click To Enlarge


Click To View (http://cmsquick.com/images/pdf/Sw/ES50M-65N_wiring.pdf)
Electrical Drawing (http://cmsquick.com/images/pdf/Sw/ES50M-65N_wiring.pdf)



Part Number
Description
Generator or Inv
Dimensions
Wt.


17-REL36050
2 or 3 Wire
50 Amp Max
8" w x 9" h x 5" d
12 Lbs


Replaces Todd TS30-30 Units


Replaces Todd TS-50... 120V 2 Wire/Ground 50 Amp Units


Replaces Todd TS-50S... 240V 3 Wire/Ground 50 Amp Units


Replaces Todd PS250, 260S & 262S... 240V 3 Wire/Ground 50 Amp Units


Automatic Transfer Switches

</tbody>

You could try replacing the wire and see if it will work again.

[gmcbuffalo]

I found this also
"If you need your Todd Engineering Sales unit tested or repaired
then give us a call at 1-336-969-0110.
We give free estimates and offer a year warranty on repairs of Todd Engineering Sales units."

[gmcbuffalo]

Sorry for so many replies but I just learned Todd is out of business. Here is a link to someone who had the same problem and how they fixed it.
http://www.irv2.com/forums/f84/transfer-switch-failed-63511.html

[JIM KELLER]

Barney, I suggest you get into a repair facility that understands the complexity of this system. Remember, those wires are hot even though the shore cord is unhooked. One of the most common causes of this problem is loose connections. A total disconnect from the house batteries might be in order. Of course if this is needed you would not have power to your dash to drive the Bus.

I think Gil needs to give some advise on this one when he can.

[JIM KELLER]

I know this probably seems like a monumental issue right now but it is all repairable. Country Coach did a good job of leaving extra wire in the loops. I had to replace my ATS [ caught it before a meltdown ] and it was fairly uneventful. The switch is rivited in and drilling is required to remove. Just be careful and don't get hurt. Most likely you will be able to replace just the switch and keep all the other parts in place.

[Gil_J]

Barney,

I'm sorry to hear of your power problem. The unfortunate reality is that our coaches can have high AC current demands leading some high current components to work at their limits. To make matters worse, we subject these devices to road vibrations and heat. One device that's worked the hardest is the transfer switch.

My guess is the burnt smell is the wires attached to the relays in the ATS. The likely cause is loose connections that will naturally occur after many miles on the road. It can be more dominant if adequate cable restraints aren't in place. Although I suspect a loose connection, it could also have been the contacts on one of the relays. It's possible for our coach's to push these relays to their rated current.

With shore power disconnected, generator AC breakers off, and just to be overly safe the inverters off, you can check out the problem. Remove the cover and look for the char. Once you find it you can determine what you want to do. Personally, I'd probably just replace it. If it was a loose connection, cut back the charred wire and reinstall the wire. Make sure the connections are tight. If it was a relay, they should be replaceable as they are common parts.

If you don't have an intelligent power monitor, you really should have one. You can now get a transfer switch combined with intelligent monitoring. There are a few options. I would rule out the IOTA product due to some fires, even though this was likely an installation problem. Some prefer the product made by ESCO, http://www.escousa.net/Merchant2/merchant.mv?&Screen=PROD&Store_Code=E&Product_Code=ES50M-65N&Category_Code=EP5 I'd go with one of ATS offerings from TRC. They have a 50A replacement or even a 90A one so you don't have to worry about pushing its capabilities. They are the one that offers a combined ATS and intelligent power monitor, http://www.trci.net/products/surge-guard/transfer-switches/50a-plus-hardwire-rvc My references are from the manufacturers, so shop around for the best price.

This should serve as a wake up call to all of us to check our high current mechanical elecetrical connections to make sure they are tight. Barney was lucky as this could have resulted in a fire.

[Barney]

Thanks fellas sorry for my slow reply, no WIFI where I'm at and I been pretty busy with my problem.
Some light in the tunnel, Today I made a few calls to some local RV service places and did not find but one guy willing to give it a look.
I guess electrical tech types are scarce around here. So, after giving the box a closer inspection, It looked to me like the relays weren't hurt,
at least no visible signs, just 5 wires that were burnt and melted to the point of shorting, one completely severed at the crimp to the connector.
I decided to put on my big boy pants and give it ago. Being scared of electricity, I first got my multimeter out and checked every wire lug, connector visible. Even though shore power was disconnected and generator off I thought there might be current from the inverters present. I had them off
at the remote panels above the dash. Anyway, I couldn't find any voltage anywhere so I decided to continue. Removed each bad wire one by one
mapped it out on paper. Wound up removing six wires.( 5 were 10 gage that either jumped between relays or ran from relay to a lug.
It appeared one wire in particular ( the one that severed) was the main failure, the others were wires that either touched this one or in the same path.
I made up new replacements and put them all back in place. I didn't find any screws or lugs that were loose.
Now for the test:
I turned off every thing in the coach, turned off the 50amp breakers in the bedroom, reconnected the shore power then had the wife turn the shore power
breaker on while I ran around looking for trouble. So far so good, but to my surprise the AC panel above the dash showed 120 volts on each of the two
meters and on one of them something was drawing 18 amps. I could hear a hum near the breaker panel in the bedroom. It actually changed volume then got real quite, not gone but barely audible. The two inverter remote panels above the dash showed the batt chargers were off, so I am puzzled about
this. Next I turned on one air conditioner, AC panels showing 18 amps on one and now 13amps on the other, still looking for trouble none so far.
Then, I turned on one batt charger ( via remote) Now 18 amps on right and left jumped up to 31amps.
About this time the thunderstorm was closing in, lightning close both of us tired so we decide to shut everything down and restart the testing tomorrow.
Not knowing where that 18 amp draw was coming from worries me. Any of you CC pals know?

Regards,
Barney

[Steve Bennett]

I would look at the 120V water heater (actually 2 in your coach). Also 24V charger for engine batteries if you have one (it will not pull 18 amps, but will pull some).

[Gil_J]

Each hot water heater should be on a different leg and I think they draw about 10 amps each. The chassis battery charger is in tool box bay under the bedroom panel. The sound described could well be a charger. 18 amps would seem like a heavy draw. Maybe, to Steve's point, you have one hot water heaters and the charger pulling current. Turn off all breakers, including the ones by the transfer switch. Then in the bedroom panel turn them on one at a time. Wait a minute and check the ampmeter. Turn that one off and move to the next. Do this until you find the one with the draw. If nothing draws current from that panel turn on the charger/inverter breakers and move to panel by the transfer switch and go through the same process.

[JIM KELLER]

My two cents. In the vicinity of the breaker panel you are close to the Inverter/Chargers. If one of them is working hard you could hear a hum inside the Bus. After sitting without power they would want to charge the house batteries. Is it possible even though the remote switch plates say the chargers are off one is actually on and trying to charge because the remote switch is in the wrong position at the Inverters ?

Barney, you're doing a good job on this issue. Tell your wife it will not always be this stressful. It just takes a while to work your way through the " New Ownership Issues ."

[Barney]

Once again info from fellow POG guys saved the day. I learn so much from each of you , thanks.
To recap and hopefully help someone else some day:
What I initially thought was going to be an expensive disaster I was able to fix myself with help from these guys for about $15 in parts.
I'll attach photos below of my plight. From my earlier comment on the mystery amp draw, I'm convinced now that in fact one of my chargers
was actually on when I thought it was off and drawing the current when I first powered up for a test.
I believe that a loose connection or a few broken strands of wire at a crimp caused high resistance and eventually meltdown of one of the
10 gage wires used in the relays. Like the guys said above, a man needs to tighten all his electrical connections on a regular basis ( annual would be good)
I think my 13 year old coach ( I've owned for 2 months) never had this done and worked loose over time and miles.
Even though these wires got redhot and melted down no break ever tripped or fuse ever blew. So lucky the thing didn't catch on fire and the damage
was contained in the switch box. Knocking on wood, all's been well for a few days of normal operation.

[dale farley]

Barney, Glad you got it repaired. Thanks for the pictures.

[gmcbuffalo]

Barney nice work. I would not put the cover on this project and wait another year. Until you feel comfortable I would keep checking it for sign of heat. Who know it may not have been a loose connection.

[Gil_J]

Barney,

Based on the pictures, it appears there was a failure at the crimp or a loose connection. If you have an IR heat gun, and you should, I'd recommend you put a high current load on the coach, at least 40A on each leg, and keep the load for at least 15 minutes. You can set the air conditioners at their lowest setting so they don't cycle and turn on the hot water so the hot water heater will stay on. After 15 minutes of high load check each connection (screw and crimp) as well as the relay contacts. You will be looking for any reading that's higher than another on L1 and L2 connections and relay contacts. There will be no current going through the generator relay and near zero through the neutral, so expect these to be much cooler.

I'm glad it was just some wire. It could have been so much worse.

While you're at it pop the circuit breaker covers in the bedroom and next to the transfer switch and make sure all connections are tight, especially the mains.

[JIM KELLER]

Barney, Glad we could help.