Transfer switch

IF, repeat IF you are safe working around 240 VAC, open it and make sure the connections are clean and tight and no wires are burned.

If you're not connected to shore power and you're not running the generator then there isn't any power coming into the transfer switch and it will be safe to open up and work on. But before you go there you might try a little diagnosis.

The transfer switch is normally set up to default to shore power. If you're getting power into the RV when connected to shore power then this side of the transfer switch is operating OK. If things aren't working then it's either the contacts are dirty or the mechanical springs aren't holding them closed.

Disconnect shore power and start the generator. After power stabilizes (about 30 seconds) the transfer switch, when operating, will connect generator power into the RV. If that doesn't happen then the transfer switch may be the problem - assuming your generator is working correctly.

Now disconnect shore power, turn off the generator and open up the transfer switch. The most likely cause is the contacts have gotten dirty or pitted. Clean then up with some emory paper and see if that solves the problem. Otherwise it could be the electronic control board that has gone bad. You might be able to find a replacement board, but the simplest thing is probably just replacing the transfer switch.

Yea I have power when hooked to shore power, nothing on just the genset. Contacts are cleaned. I was in NM when it stopped working. I ended up disconnecting the shore power leg and wiring the generator leg into where the shore was to get us home with some AC. But the transfer switch for sure is done. Just wondering if anyone had a suggestion on a replacement.

I've installed a few Progressive Dynamics PD52V's as replacements with no complaints to date.

bob_nestor wrote:
If you're not connected to shore power and you're not running the generator then there isn't any power coming into the transfer switch and it will be safe to open up and work on.

You're probably correct that there is no power but, you should always check it with a meter to ensure the circuit is dead. Many electricians get electrocuted assuming that a circuit is dead when it isn't. Since I'm not there I would think that an inverter if installed and operating could backfeed and supply power. JMO

FIRST, ensure power is OFF. SECOND, if you have an AUTO-START make sure it's OFF.
THIRD, check with a meter BEFORE working on it. Since you've already been in there most likely you know what you're doing, just be extra safe.

Mine is an ESCO ES-50 with built in Surge protector. Have you checked the contactors? There are two and usually one is all you'll need to replace rather than changing out the whole assembly. Good luck....Dennis

ES 50 Surge

I replaced mine with the ESCO LPT50 BRD. It has DC relays so no humming.
Been working fine the last few months.

After 2 failed.......1 after 8 months/replacement failed right out of box I was DONE with 'auto transfer switches'


I did away with it....replaced with 'manual transfer'
125 amp subpanel with 50A double throw CB's mechanically interlocked.
1 for shore power feed, 1 for generator feed.

DONE. And if parts needed.......any hardware store. $10/CB

For superior performance consider PD53-100

Have you determined the issue with the old TS?

Since your original has worked for 11 years I wouldn't be afraid to replace it with same.