Liberty Inverters/Shore Power

[Lee Bornstein]

Need to leave my coach in unattended storage for 3 days with a fridge full of food and only 20A electric available.

Thought I'd just turn off inverters and chargers and all circuits except for fridge.

Good Idea YES BUT fridge is only on inverter circuit and Inverter must be on in order for fridge to work.

In a 97 Liberty that's plugged in to shore power, does inverter (When Turned On) actually create 110V from 12V or does it Pass Thru the 110V?

Don't want to run watchdog while Im away for 3 days - don't trust it.

Lee

[Joe Cannarozzi]

I'd be really supprised if that fridge did not work off of shore power with the inverter off.

20 amp should be enough if its the only thing on.

If it does need the inverter to power it, just so long as the batteries are fully charged when you drop and the chargers don't need to put out 30 or 40 amp. innitially, a 20 amp. circuit still should be O/K and use the watchdog for back-up.

[Jon Wehrenberg]

Lee, you need to leave your inverters and battery chargers on along with the refrigerator circuit breaker. If you shut everything else off you will not have a problem.

I say that assuming you have set the dip switches in the rear of the small inverter panels to the lowest charging rate. The inverter manual gives the dip switch settings for this. That way the battery chargers will draw the least power.

I hope you have tried a 20 amp circuit. If it is a GFCI protected circuit you may not be able to use it because it will see a ground fault due to the way the coach automatic current switch is set up.

[Lee Bornstein]

John:
I have one charger set at 30A and the other at 50A. When running on 30A service I shut off the 50A charger.

I will reset the one inverter to 20A and test when I get to the farm in IA tomorrow. Have to leave coach there and drive car (quick trip) to Nebraska to pickup new puppy then back to IA and continue north to Canada by end of month.

Lee

[Jon Wehrenberg]

Lee, I'm sure you will be OK. With charged batteries I only draw about 6 amps with the refrigerator running and all other circuits except the inverter and charger circuits turned off.

[JIM CHALOUPKA]

John:
I have one charger set at 30A and the other at 50A. When running on 30A service I shut off the 50A charger.

I will reset the one inverter to 20A and test when I get to the farm in IA tomorrow. Have to leave coach there and drive car (quick trip) to Nebraska to pickup new puppy then back to IA and continue north to Canada by end of month.

Lee

Lee, what kind of puppy??

Have the farmer keep an eye on the bus.

What kind of paperwork is required to take a dog back and forth over the Canadian border???:confused:

[Danss]

Must have proof of Rabies Vac. Dan

[Joe Cannarozzi]

What is the advantage of only being able to run the fridge through the inverter?

[Jon Wehrenberg]

The fridge is not run through the inverters per se when connected to shore power or when the generator is running.

If my understanding is correct (I welcome a correction if I am wrong) the inverters have an internal relay which closes when shore or generator power is sensed. When the relay is closed the refrigerator (and all inverter circuits powered circuits) are directly connected to shore power.

If the inverters are turned off it is possible the relay does not close so the circuit for the fridge is not powered.

Liberty sets the inverter / charger circuits up separately so the inverters can operate without the battery charger function working and vice versa.

[truk4u]

My Marathon must have the Inverters on even when plugged in. I'm going to add bypass switches if Big Red stays home.;)

[Jon Wehrenberg]

Tom,

Think that through carefully. As long as you never power the circuits from inverters and shorepower at the same time it sounds like your equivalent of a mechanical transfer switch will be OK, but I see bad stuff happening if the shore power is on the circuit and the inverter is also trying to power the same circuit.

[Joe Cannarozzi]

Now that makes more sence to me.

Our inverter has that switch, I had to replace it, it was bad.

So back to the original question. If this is the case why is it nessesary for Lee to have to leave his inverter on while away? Why would they build a bus without it, like Toms?

[Jon Wehrenberg]

Joe,

If Lee turns off his inverters I don't think the relay closes to allow shore power to go to the refrigerator circuit.

Unless someone has modified Lee's coach (and almost every other) the inverters need to be on. Lee's original question about current draw tripping a 20 AMP circuit is actually more related to his battery charger settings and circuits. On the low settings he can leave the inverters and chargers (4 separate circuit breakers in our Libertys) "on" and not only keep the fridge working, but keep the batteries topped off.

[Lee Bornstein]

Jon:
Can't prove it but it's my educated guess that all 8 circuit breakers on my power panel labeled "Line 1 Inverter" are powered only as inverter loads and only operate if inverters are ON (4 circuits on Inv #1 and 4 Circuits on Inv #2).

If I turn off inverters while plugged in to shore power or Generator those circuits are DEAD.

Im at the farm right now plugged into a 20A circuit running one Charger with DIP switches set to limit a 20A draw. Inverters are both on and inverter breakers are off except for fridge. Power draw at this moment is 10A and all should be OK while I'm gone.

JIm:
As far as the dog goes - I have an 18month old Std Longhaired Dachshund and am going to Northe Platte, Nebraska tomorrow to pick up 10 Wk old Std LongHaired Dachshund then return to Marshalltown IA thursday, pickup coach and continue north to Wisconsin and Canada.

Entering into canada - dogs over 3 months of age need Rabies certificate or will be required to have vaccination within a specified time period with proof being shown to authorities.

[Jon Wehrenberg]

Lee, if you have any questions about your load on the 20 amp circuit just read the amps off your panel. Unless you load up the batteries with lights or some other loads your chargers will draw very little and the fridge will draw about 5 or 6 amps.

[JIM CHALOUPKA]

Sounds good Lee, Hope the dog or (_i_ch) is everything you were expecting. I think you will be having a (hand full ) on this trip.:eek: :p No animals between the driver and the wheel now. You Hear!:D
The medical requirements for dogs then are not as stiff as I thought (such as for horses).
Have fun!
:) JIM

[Lee Bornstein]

Coach ran flawlessly on 20A for 3 days. One charger limited to 20A kept Batteries topped off and only inverter load was fridge.

Minimum power drain was 2A with batteries charged and fridge compressor off.
When Fridge Compressor ON, load jumped up another 6Amps.

Lee, Barb, Jack & Jude
Camped on the banks of the Zumbro River near Rochester MN on our way to Frostbite Falls, MN

[JIM CHALOUPKA]

Coach ran flawlessly on 20A for 3 days. One charger limited to 20A kept Batteries topped off and only inverter load was fridge.

Minimum power drain was 2A with batteries charged and fridge compressor off.
When Fridge Compressor ON, load jumped up another 6Amps.

Lee, Barb, Jack & Jude
Camped on the banks of the Zumbro River near Rochester MN on our way to Frostbite Falls, MN

Lee, This sounds great throw in a picture or two.

[win42]

Jim, What the H are you dragging a dog into the important subject of storage, inverters and chargers. Keep the thread creep to yourself. Your not required to comment on every thread that gets posted. That priveledge is reserved for the Lewster & I.

[Jon Wehrenberg]

Harry,

I hope Lee's post about current draw assures you that storing the new baby with only 15 amp of shore power should prove to be no problem at all.

(Jim, sorry for hijacking your thread!)

[JIM CHALOUPKA]

Jim, What the H are you dragging a dog into the important subject of storage, inverters and chargers. Keep the thread creep to yourself. Your not required to comment on every thread that gets posted. That priveledge is reserved for the Lewster & I.

:D Harry, Just remember Creep/Crap is in the eye/ear of the beholder:eek:

Crap/Creep to one is Music to another:p

Just because you have TWO buses don't be feeling Cocky:cool:

[Lee Bornstein]

New Inverter Experience!

Just pulled into new campground with 30A service. Plugged in coach, flipped 30A breaker on post and breaker immediately tripped.

Scratched my head, went inside and turned off all AC Breakers to eliminate all load. Filpped breaker on post again and it tripped.

Scratched my head again, unplugged coach, reset breaker and it stayed on.

Then, with all this head scratching I remembered something someone said earlier in this thread... Inverters will not run on GFI protected circuit. Sure enough, the 30A breaker on post was GFI. Looked at other sites in park and no GFI on the 30A breakers.

Site I was assigned to was only one with 30A GFI.

Convinced the campground manager that since I was paying for Full Hookups that it would be nice to get a site that was compatible with my coach.

Moved to new site, plugged in, turned on all breakers and we're comfy and happy here in the North Woods in Gilbert, MN.

Lee
See us on the map: http://map.datastormusers.com/user1.cfm?user=2352 ("http://map.datastormusers.com/user1.cfm?user=2352")

[Jon Wehrenberg]

Lee, the ground fault is likely related to the transfer switching in the coach and not the inverter. But the fact remains we will trip a GFCI with coaches that are set up like our Libertys. I cannot say anything about any other converter's product because theirs may be set up differently.

GFCI 30 amp receptacles (or breakers) are coming. It is just taking time for the codes and UL standards to get wide acceptance.

I am not selling Thompson Coaches, but I know Rick Thompson has given this area in his coaches a lot of thought, and his method of doing a "soft" changover from inverter to shore or generator power will not trip a GFCI. I really like his coaches because of the logic that he has built into the electrical system.

[gmcbuffalo]

Jon
How does this "soft change over" work or it's concept?
GregM

[Jon Wehrenberg]

Greg,

I wish Rick Thompson would post an explaination here, but absent that I will give a limited answer.

Whenever our coaches that have automatic transfer switches go from one power source to another, such as from inverter to shore power or generator, relays handle the switching action. If a circuit such as the shore power circuit has a lot of devices in the "on" position and they are not under power from the active circuit, such as the inverters, a heavy load is imposed and arcing occurs on the contacts. This is probably not a big deal if it is a small load, but if it is several Cruise Airs powered up simultaneously, the starting load is large.

When such a load transfer is made, it is beneficial if loads are shed or off of the system until the switch is made, and then are turned on at varying times so the systems such as the 50 amp circuit breakers are not tripped by a sudden overload.

It is good practice to manually or automaticaly shut off all loads each time we go from one power source to another, although it is not always possible or practical, such as when a generator is set for auto-start, or when there is a campground power outage. I know Thompson for one has an extensive system for handling loads and controlling demands.

[Gary & Peggy Stevens]

Jon, have you ever seen one of Thompsons used coaches http://www.thompsoncoach.com/usedcoaches.html for sale? Maybe he hasn't had them in the market long enough for them to come out in a used condition?

When Ben and Peg and I looked at his bus in Tampa, at the RV Show, it truly was a remarkeable bus. He has really put some thought into his electronics.

Gary S

[Jon Wehrenberg]

I saw one on RV Trader that hung there for a while.

Di and I really like his electrical systems. He has made it so the coach is literally all automatic.

[merle&louise]

Gary,

I remember about 9 months ago, a Thompson coach (no slides) was for sale on eBay. If I remember correctly it was a 2001 and it had a buy it now price of $360,000 which I thought was a great deal. I don't know if it actually sold (it probably did) but I never saw it on eBay again. It was very nicely finished inside and the outside was blue, silver, and s.s.