Transfer Switch question.

Topic: Transfer Switch question. (Read 502 times) previous topic - next topic

Transfer Switch question.

August 07, 2019, 03:58:54 pm

A little strangeness the other day. Driving through rain with genny on so I could have some ac. Passengers commented that AC was off, but genny was running.
Pulled over to take a look.
1) cycled breaker on genny. No love.
2) cycled breaker again, harder this time. Still no love.
3) cycled main 120V breaker under bed. Nope.
Repeat steps 1, 2 & 3. Yea, transfer switch does its "thunk" and we have power.
So.....
Any theories?
Second, I know WHAT the transfer switch does, but not HOW.
Are there two sets of electro magnets that energize to take shore or generator power? I assume so, as I hear it even either power comes on.
Always heard that shore power had priority over generator. How?

Re: Transfer Switch question.

Reply #1 – August 07, 2019, 04:09:49 pm

Did you cycle the A/C breaker?

Re: Transfer Switch question.

Reply #2 – August 07, 2019, 04:35:33 pm

Quote from: craneman – August 07, 2019, 04:09:49 pm

Did you cycle the A/C breaker?

I had no AC anywhere in the coach. Voltmeter by door was showing 0VAC.
Funny you ask, I cycled ALL breakers, even if they didn't need it.

Re: Transfer Switch question.

Reply #3 – August 07, 2019, 04:37:03 pm

Does your generator have a breaker? Mine does, but I am several years newer.

Nevermind, I see you checked.

Re: Transfer Switch question.

Reply #4 – August 07, 2019, 04:44:43 pm

Quote from: Moby – August 07, 2019, 03:58:54 pm

Second, I know WHAT the transfer switch does, but not HOW.
Are there two sets of electro magnets that energize to take shore or generator power? I assume so, as I hear it even either power comes on.
Always heard that shore power had priority over generator. How?

No theories on your first question. Stuff happens.

As to the second, I found the YouTube video below from Progressive Dynamics. It provides a quick look at the inside of a transfer switch, and how to check for proper operation. I imagine the way the contactors are pulled down is probably similar to a solenoid switch (like the boost solenoid). Energizing a coil (electromagnet) moves a shaft which moves the contactor? Just guessing here...

I have heard that the ATS can be "set" for either shore power priority or generator priority, but I don't know how this is accomplished. I have read on the Forum of members finding both setups in their coach. I'm sure one of our techie experts will add more info on this subject...

What has AC Priority

https://www.youtube.com/watch?v=WGSFBlB75DA

Re: Transfer Switch question.

Reply #5 – August 07, 2019, 05:25:22 pm

One of the times mine quit working it was the 5 amp push button on the front of the generator control panel. It powers the exciter field I believe. Not sure if your '93 has one.

Re: Transfer Switch question.

Reply #6 – August 07, 2019, 05:27:41 pm

Quote from: craneman – August 07, 2019, 05:25:22 pm

One of the times mine quit working it was the 5 amp push button on the front of the generator control panel. It powers the exciter field I believe. Not sure if your '93 has one.

Sounds like a circuit breaker.
Mine has a fuse.
More curious as to why I had to cycle the breakers a couple of times.
Going bad?

Re: Transfer Switch question.

Reply #7 – August 07, 2019, 06:27:41 pm

IF, repeat IF you are safe working around 120 VAC, open the ATS and check connections, That is the first step.

Another place to check is the box in/next to the generator compartment where the generator wiring is wired to the house wiring on its way to the ATS.

Re: Transfer Switch question.

Reply #8 – August 07, 2019, 09:51:11 pm

If a breaker trips you need to turn it all the way off. A lot of time you will hear it click then move the lever to the on position. Can not tell you how many times I've been asked "What did you do, I had already tried that

Re: Transfer Switch question.

Reply #9 – August 07, 2019, 10:09:01 pm

Couple of points/questions.
1) Volt meter by door was 0 VAC.
Where is this measurement taken? I ASSUME after the ATS as when genny is warming up the meter shows 0 volts but comes up to normal AFTER I hear the ATS do its thing.
2) I cycled the generator breaker several times.
3) I then went inside and cycled the main breaker (under the bed) several times.
Note, a short period of time had to elapse between #2 & #3
4) I repeated #2.
5) As I was repeating #3, the ATS functioned just as I was turning the main breaker ON.

So, is it a one in a billion coincidence in timing?
Is the main breaker somehow related to the ATS?
Is this just a "I Donna know what happened but it works now" situation?

Re: Transfer Switch question.

Reply #10 – August 07, 2019, 11:41:25 pm

Progressive cycles in 2 minutes,

Re: Transfer Switch question.

Reply #11 – August 08, 2019, 12:08:46 am

I believe the generator has priority. When you plug the shore power in, the transfer switch switches from Generator to shore power... I have had problems with the Master Switch, mine is in the stair well. It gets bumped by accident, turning it back on and all is well !
Safe travels
Dave

Re: Transfer Switch question.

Reply #12 – August 08, 2019, 12:20:09 am

My 97 was wired to be shore power priority. We rewired it to be gen priority instead.

Bad shore power and the progressive shuts power off you can start the gen and not have to runout and unplug the shore power.

Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 11, 2025 ...

Transfer Switch question.

August 07, 2019, 03:58:54 pm

Re: Transfer Switch question.

Reply #1 – August 07, 2019, 04:09:49 pm

Re: Transfer Switch question.

Reply #2 – August 07, 2019, 04:35:33 pm

Re: Transfer Switch question.

Reply #3 – August 07, 2019, 04:37:03 pm

Re: Transfer Switch question.

Reply #4 – August 07, 2019, 04:44:43 pm

Re: Transfer Switch question.

Reply #5 – August 07, 2019, 05:25:22 pm

Re: Transfer Switch question.

Reply #6 – August 07, 2019, 05:27:41 pm

Re: Transfer Switch question.

Reply #7 – August 07, 2019, 06:27:41 pm

Re: Transfer Switch question.

Reply #8 – August 07, 2019, 09:51:11 pm

Re: Transfer Switch question.

Reply #9 – August 07, 2019, 10:09:01 pm

Re: Transfer Switch question.

Reply #10 – August 07, 2019, 11:41:25 pm

Re: Transfer Switch question.

Reply #11 – August 08, 2019, 12:08:46 am

Re: Transfer Switch question.

Reply #12 – August 08, 2019, 12:20:09 am

Affiliate Notice