Liberty Transfer Switch

[phorner]

Our Liberty has a 50 amp breaker mounted on the transfer switch in the first bay.

My question is, how do other Liberty owners use this? When I first purchased the bus, I was told to always shut this breaker off prior to disconnecting from shore power. Then shut off the 50 amp breaker in the power pedestal before removing the shore cord.

To connect the shore cord, to always make sure the power pedestal breaker was off, plug in the shore cord, turn the power pedestal breaker back on and lastly turn on the 50 amp breaker on the Liberty transfer switch.

This sounds reasonable, but it leads to using the 50 amp breaker mounted on the transfer switch as a "switch" of sorts, and I've always been under the impression that breakers should not be switched off and on (such as a switch) on a regular basis.

I would appreciate any comments.

[MangoMike]

Hi Paul,

On my Liberty I just turn off the breaker at the pole and disconnect.

Not that this is the recommended way, just the way I was taught by B-O-Bxx.

[phorner]

Thanks, Mike.

Seems to me that when the breaker at the pole is off, that the transfer switch will sense the loss of energy, thereby eliminating the need to shut off the transfer switch breaker because, at that point, electricity isn't flowing through it anyway.

My concern is overusing that breaker on the transfer switch and weakening it.

[jack14r]

Paul,I do as mango does.

[truk4u]

Me too like Mango Paul...

[phorner]

Seems as though we have a consensus.

I'll quit playing with the breaker and find something else to do :eek:

Thanks everyone for your input...:)

[jelmore]

Paul, isn't your coach set up like mine? Here's a pic of mine: http://2000liberty.info/all_pics/l/P8154211.jpg

This is a pair of 70 amp breakers linked together and they are called shore power breakers. The Liberty instructions say to flip those on only after checking on your inside control panel that the polarity is correct from the shore power. That's what we always do, though I've never seen the wrong polarity from any shore power. That would probably be a disaster if that was connected.

I didn't think that was the transfer switch. Of course, I don't really know what a transfer switch is or where it is located, but I thought a transfer switch switched from shore power to generator power or perhaps to inverter power. Never had to deal with that thing.

[Jon Wehrenberg]

Dittp. Just as a piece of information, breakers are not intended to be used as switches. They are intended to be used to shut off power on those rare occasions when you want to turn off a circuit, so instead of turning off your 50 amp switches and having premature failure, subject the campground breaker to that use.

[phorner]

That was my line of thinking, Jon. It seemed like it was unnecessary and probably bad practice to keep shutting that breaker off and on every time I connect to shore power.

My first clue should have been that none of the Liberty service tech's used it.

I knew better but didn't trust my own good judgement. Of course, this wouldn't be the first time....

[truk4u]

Jim,

That's a pleasant surprise, mine looks identical to yours, double 70's. I just assumed my vintage would have been different.;)

I always plug in the Progressive box before I hook up to make sure all is in order at the power pedestal.

[phorner]

Jim,

Yep, that's the same as ours.... except we don't have the "Dog" switch.

[Ray Davis]

Marathon's are probably setup different than the Libertys, but in my case I have a large breaker with 5 indicator lights below it. I was told that I should turn it off, plug in the power to the pole, turn on the pole CB, and IF the 5 lights indicate correct polarity, then it's safe to turn on the breaker in the bay.

I sorta agree that you don't really want to be using this CB as a switch, however how else would you be able to test polarity before allowing external power to pass into the bus. Obviously, if you are using an external device like the PT-50C, then that solves it. But in the absence of that, what would be the suggested method.

It would seem that if you don't cut the internal breaker first, and simply turn on the external power pole breaker, that you aren't sure what you're getting?

Ray

[gmcbuffalo]

Ray the way your coach is designed the circuit breaker is meant to be a switch. If it needs replacement down the road is will have been a cheap insurance.
GregM

[Ray Davis]

Thanks Greg

[phorner]

OK, so I probably shouldn't have brought up anything about the transfer switch 'cause now I may have an issue.

The last couple of times that I've connected to shore power, the transfer switch has not engaged fully on the first try. It kind of clicks on and off a few times, then finally latches. The current park has good power (we're now at Hacienda RV Park in Las Cruces, NM) so I don't think that park power is the culprit.

So, does sound like a problem in the making or is there a reasonable explanation as to why this would happen. In the past, there would only be a single, significant "clunk" as the transfer switch sensed power and latched.

Any ideas?

[MangoMike]

Paul,

I had that same problem on the Liberty and there is a plug in relay with a red top that engages that transfer switch. In fact as I recall there are two, one handles shore power and one handles generator power. I had the shore power one fail and continue to click. As an immediate remedy Liberty had me switch those two relays so that I could get shore power to work. You might want to try that. I couldn't find any pixs to post.

I'm sure Jon will chime in with a little more detail.

Mike

[phorner]

Thanks, Mike.

I'm familiar with those relays, which I believe are time-delay relays. I'll try to get a spec on them and see if I can locate a spare. Swapping out the generator relay is a good suggestion as a quick fix.

[mike kerley]

Paul, Many of the commercial generator transfer switches (especially the older ones) use those same plug in time delay relays. The control voltage may vary with your Prevost versus a commercial unit, but my guess is a local generator repair shop would stock those relays in your voltage range.

[Jon Wehrenberg]

I agree with Mike Squared. Don't overlook WW Grainger as a source. You may need to create an industrial account but once established you can get parts anywhere they are located around the country and they will overnight stuff right to you. I sometimes think half of my bus came out of the WW Grainger catalog.

[Pete]

Jon.....so now we have the truth, you have a Liberty-Grainger conversion! Now we know what makes Liberties so good. (just kidding).

[GDeen]

The lowly Marathon conversion also has the shore power breaker disconnect. Obviously they copied the technology from Liberty.

Ray, my owners manual recites the procedure you gave as the proper way to connect and disconnect from shore power. In fact, it is in bold lettering so one would assume that breaker switched is designed for that operation in our coaches.

[Ray Davis]

Well, then. I GOTTA follow that bold lettering stuff! :rolleyes:

[GDeen]

Well, then. I GOTTA follow that bold lettering stuff! :rolleyes:

Thats what I'm thinking - those lawyers are serious about bold lettering :)