Community Forums

lanerd · 01-24-2017, 01:10 PM

Recently, with my MH winterized in my rv garage and connected to 30 amps through a Surge Guard model 34850 and a 30 amp dog bone, my transfer switch failed and over a period of a couple of weeks, drained my 6 6v Interstate batteries to almost 0. I replaced the batteries and purchased a new transfer switch and had it installed. All is working fine now.

However, what would cause my original transfer switch to fail....and only the shore power relay as the generator relay was fine?

I also submitted the same post over at another forum.

Ron

icepick · 01-24-2017, 01:23 PM

because Mfg's use POS transfer switches. I know thats not the answer your looking for but I cant explain it any better. Best suggestion is to not have any major load when plugging in or out of shore power or when starting the generator.

D Lindy · 01-24-2017, 04:15 PM

Just like anything else electrical/electronic, these things can last 1 month/year/century. Anything can fail at any time, just the nature of things.

vettenuts · 01-24-2017, 06:08 PM

Not sure how many do this, but it's a good idea to check tightness of the wire connections annually. Loose connections can cause issues. Not sure what make/model you have but some have issues and recalls.

Mike and Cha · 01-24-2017, 10:06 PM

I just went thru the same thing, for no reason at all the transfer switch went out while plugged into shore power, while the MH was being stored at our house. I found it when I was checking the MH and it could have only been out for a couple weeks max. Our batteries only ran down to 12.1. Like you I was hooked up with a surge protector when it went out and the generator side still worked. I checked everything I could, all the wires were tight, and it didn't appear that anything had been done wrong. I never plug into shore power with anything on inside the MH, nor have I ever started the generator while plugged into shore power. My mechanic said that it could have just been the luck of the draw and we had a weak transfer switch to begin with or it could have been a brown out type power outage as we were out of town when it occurred. He said those tend to fry the shore power side, and lock it in the open(non-functioning mode) which is exactly what happened. It was stuck so hard you couldn't move it even by hammering on it. Either way the new one seems to work better, and does not clunk as loud or hum as loud(or at all) as the original one did.

Unplanned Tourist · 01-24-2017, 10:10 PM

Quote:

Originally Posted by Mike and Cha

I just went thru the same thing, for no reason at all the transfer switch went out while plugged into shore power, while the MH was being stored at our house. I found it when I was checking the MH and it could have only been out for a couple weeks max. Our batteries only ran down to 12.1. Like you I was hooked up with a surge protector when it went out and the generator side still worked. I checked everything I could, all the wires were tight, and it didn't appear that anything had been done wrong. I never plug into shore power with anything on inside the MH, nor have I ever started the generator while @plugged into shore power. My mechanic said that it could have just been the luck of the draw and we had a weak transfer switch to begin with or it could have been a brown out type power outage as we were out of town when it occurred. Either way the new one seems to work better, and does not clunk as loud or hum as loud(or at all) as the original one did.

Have to agree a low power (brown out) could have been the cause.

vettenuts · 01-25-2017, 03:06 PM

Quote:

Originally Posted by Mike and Cha

I just went thru the same thing, for no reason at all the transfer switch went out while plugged into shore power, while the MH was being stored at our house. I found it when I was checking the MH and it could have only been out for a couple weeks max. Our batteries only ran down to 12.1. Like you I was hooked up with a surge protector when it went out and the generator side still worked. I checked everything I could, all the wires were tight, and it didn't appear that anything had been done wrong. I never plug into shore power with anything on inside the MH, nor have I ever started the generator while plugged into shore power. My mechanic said that it could have just been the luck of the draw and we had a weak transfer switch to begin with or it could have been a brown out type power outage as we were out of town when it occurred. He said those tend to fry the shore power side, and lock it in the open(non-functioning mode) which is exactly what happened. It was stuck so hard you couldn't move it even by hammering on it. Either way the new one seems to work better, and does not clunk as loud or hum as loud(or at all) as the original one did.

Wonder how low the voltage got? My Progressive Industries EMS cuts power at 108 volts (from memory) and wonder if this would save the transfer switch in this type of scenario.

Mike and Cha · 01-25-2017, 03:15 PM

I have no idea, we were out of town and got a message on our phone that we had a power failure. We have had other power failures where it was a brown out so to speak as the power just continued to get lower until everything went out. The MH was plugged in for those, the only difference is that when the power went out I unplugged the MH until the power was fully restored. This time I wasn't home to do that. When we got home I checked the MH and that's when I found the problem. I was hooked up to a surge protector though.

Sweetbriar · 01-25-2017, 04:37 PM

Normally, but not always, the transfer switch default unenergized position is to supply shore power to the coach. If the switch Tiffin used during construction works this way then the switch was just passing power with spring pressure holding the relays in the shore power position.

The Surge Guard (mine is a generation younger) would have disconnected the coach if shore power volts dropped below or above certain limits so I don't think that would have caused a problem with the switch. Particularly when laid up for storage. My 50 amp coach is sitting in my drive set up just the same on 30 amps. Sixth winter without a problem.

A fail when in storage with little load is a difficult question to answer. Any idea what make and model switch it was and an image of the relays?

twinboat · 01-25-2017, 04:55 PM

Quote:

Originally Posted by Sweetbriar

Normally, but not always, the transfer switch default unenergized position is to supply shore power to the coach.

That is true of 30 amp transfer switchs but most 50 amp transfer switchs have 2 independent contactors. On application of shore power, one closes to pass that power.

If you start the generator the shore power contactor opens and the generator contactor closes after the 30 second delay.

This is from the Progressive site.