Liberty Generator Fan Blower, Intermittent

[MangoMike]

On the Liberty there is a squirrel cage fan motor behind the radiator for the generator. If this is cycling on and off (as mine was doing in OSH) during generator operation then it's time to take a peek under the bus. There's a really good chance that the baffle is missing. This baffle directs the hot air away from the intake side of the generators radiator, causing the blower motor to overheat and shut down for a limited time.

A new baffle is available from Liberty for a mere $350 Lewbucks.

Mike

[truk4u]

Mango,
My fan cycles on and off as needed and is normal. It's possible that my setup is different, better being a Marathon, but it's designed to cycle based on temperature, kinda of like the radiator fan.

[MangoMike]

Tom,

That made sense to me and I kept on telling Jon that, but I stopped at the Liberty factory while leaving OSH and they confirmed the overheating issue as related to the missing baffle.

I hate it when Jon's always right. Jeez.

Mike

[Jon Wehrenberg]

Actually hit man Frank spelled out exactly what mango's problem was. Mango, send your fax number and I will send a sketch of the baffle. I have Wendi quoting it for me.

[Just Plain Jeff]

Jon was dead wrong.

Hitman Frank was wrong.

I was right.

Buy a new bus.

[Jon Wehrenberg]

Tom, I think your post raises a good topic for general discussion if you are willing. We often talk about everybody's leveling systems being different depending on converters, but we actually need our generators much more than we need good leveling systems, yet there is little discussion of them.

Your post about your generator fan cycling makes me wonder what is the correct operating characteristics of our generators?

I'll outline what I think is correct for a Liberty, and perhaps you can share along with others what is correct for your respective converters.

On both my 1987 and 1997 Liberty the generators were located ahead of the driver side drive axle. The radiator and cooling fan was located on the same side in the second bay. Between the two coaches there were differences. On both coaches the radiator cooling fan was powered by 120V output from the generator and was protected by circuit breakers in a box to the LH of the radiator. The 1987 had in addition a 120V water circulating pump located in front of the radiator. It was also powered off the generator and was protected by a circuit breaker. The 1987 generator had a Kubota engine and the 1997 has a Yanmar. The 1987 used house battery power to start, and the 1997 has its own dedcated battery. Both gensets were supported on small airbags inflated off the auxiliarry air circuits.

The generator boxes were ventilated by small fans (I think).

Both had an opening in the floor in front of the radiator for cooling air and hot air from the radiator fan was exhausted from the bottom of the coach just behind the radiator. The hot air passed through a steel baffle that directed the flow of air towards the rear of the coach. In that way the air coming into the radiator was ambient air, and by directing the hot air rearward, the cruise air(s) that were mounted in the center of the coach belly were not drawing in heated generator air into the condensing units.

When Mango talks about his radiator fan motor cycling on and off, what was actually happening because of his missing baffle was his radiator was having heated air drawn across it and the fan motor, and the fan motor was cycling on its internal over temperature safety switch.

I know Tom's generator is located in a forward bay, but I don't know if the always "on" radiator fan such as in our Libertys is typical or if other converters cycle their fans.

[truk4u]

Jon,
Good idea, sounds like each converter kind of does something different. Here's the deal on my Marathon to the best of my knowledge:

Mine is a 20KW Powertec with a 4 cylinder Kubota engine. The gen is located in the first bay, port side. The gen has it's own dedicated 27T batteries hooked in parallel and located on the opposite side with the house batteries. The gen batteries have a factory solar panel for charging. I assume the gen and batteries located on the opposing sides are for balance and front axle weights confirm that.

The gen is in an insulated compartment with 4 air bags (manual fill) and of course a slide out. The radiator is located in the center of the bus with two large air grills underneath and a squirrel cage type fan. The fan not only cools the radiator, but also pulls air from the gen compartment through a grill and pulls air out of the battery compartment through a grill. Seems like a dual purpose arrangement to keep hot air moving outbound. There is a seperate 120v circuit breaker for the radiator fan.

The fan cycles on/off as needed based on temperature. There may be a lower fan speed that I can't hear and high speed as needed. I'll ask that question at the Marathon Rally starting today in NC. I did ask about the fan cycling, and that was the way it was intended to operate, just like a radiator fan. I do not see any change in the gen coolant temps as the fan cycles, it stays about 160.

I'll post more info as I get answers.

[rfoster]

Mango: Stopping by the factory, That has got to give a guy Chronic MPD!

[Jon Wehrenberg]

I don't think that is as bad as going to Stuart or to a converter rally.

At the factory you see buses in pieces. Ugly, complex, not finished, lots of people trying to put pieces together and having a hard time doing that. That tends to be scary unless you arrive just when they roll a recently completed coach out the door.

At rallies and the sales center the buses are all pretty, assembled, and with the slides extended and just waiting for your name on the title. That is a dangerous place to be especially when you have some things wrong. I think Mike has decided that instead of spending $350 for a new baffle and $1500 for a new Watchdog he will just buy a new two slide Elegant Lady.

[Jon Wehrenberg]

This is a blatant sales pitch.

Mike lost his baffle for his generator. Liberty will sell him a new one for $360.

If there are any Liberty owners who have damaged their baffles, or lost the baffle, I have gotten a price from my old shop. For a new, unpainted baffle assembly the cost will be $100. If you want it powder coated black or gray (no choice, it will have to be whatever color is runnning)the cost will be $125. Costs do not include UPS charges.

Some drilling may be required because on my coach it seemed like the holes were drilled and may vary from coach to coach.

I will post a similar message on the Prevost Stuff site.

This baffle will prevent some of the problems Mike is now experiencing.

I am not making any money on this, but if that makes anybody feel bad you may make a large contribution to the King of Bling LED fund.