Generator Air Bag setting

[mike kerley]

For the brain trust. Our 17.5 KW PowerTech generator sets on four small air bags with the pressure controled by one regulator. It seems to take 20 lbs just to get the front of the engine to lift the frame off of the deck, another 5 -10 to lift the rear/generator portion. Does this fit the norm, or do I have bag issues?? Cannot see the rear bags!

I also seem to get a lot of movement lately when the bags are inflated to 30 lbs. the generator dances a bunch. Does not seem to be missing or running rough, just dancing around.

What pressure is works best and any thoughts on "the dance"?

Thanks in advance,

[rahangman]

While we are sitting here in Pass Christian, MS , I will go out to see if I can determine...after the 6" of water subsides...whew, more comin today!

[merle&louise]

Rodger,

6 inches of rain is nothing; during hurricane season we get that everyday. If you were a true cajun (like me) you could use your webbed feet to swim!

Just kidding; that was some terrific weather last night! And you're right - there's more to come!

[JIM CHALOUPKA]

For the brain trust. Our 17.5 KW PowerTech generator sets on four small air bags with the pressure controled by one regulator. It seems to take 20 lbs just to get the front of the engine to lift the frame off of the deck, another 5 -10 to lift the rear/generator portion. Does this fit the norm, or do I have bag issues?? Cannot see the rear bags!

I also seem to get a lot of movement lately when the bags are inflated to 30 lbs. the generator dances a bunch. Does not seem to be missing or running rough, just dancing around.

What pressure is works best and any thoughts on "the dance"?
Thanks in advance,

Mike, the label under my gauge for the gen. bags states 14 #, mine is set at 20#. I do not have excessive movement.

JIM :)

[dmatz]

Mine is a 20k power tech and set at 20lbs as well. I did have a bag go bad on my 17.5 PT on a 2002 royal. coach. PT has great support call them they will tell you the psi. Perhaps your gauge is not correct?

[JIM KELLER]

Good Thread Mike. I'm especially surprised with the 14 lb number Jim just posted. I'm sure he is right because he is a Tech Guy. On my 17.5 Power Tech I run two different pressures. The Generator end of the assembly weighs the most. Stands to reason the unit would not be perfectly balanced. I run 45 lbs on the Generator end and 35 lbs on the other end. Seems like a lower pressure allows the unit to slop around on its mounts while the Bus is on the road. I was surprised how much I could push the Generator around on the bags at a lower pressure. Part of the assembly actually hit the inboard side of the Cargo Bay until I increased the stiffness of the Bags. If I'm all wrong someone let me know !

[GDeen]

The regulator on mine went bad last year and would allow high pressure to pass through to the bags. At higher pressure, the dampening effect is minimized which makes normal vibration noticeable in the coach. Mine is a 20KW Kohler, and Marathon specifies 25 psi in the bags. After replacing the regulator (found an almost identical version at Lowe's) and tweaking the pressures around, 25 seems to be the best for my setup.

[mike kerley]

Thanks everyone for your responses.

Doug, When your Royal had a bag fail, what did it do to the generator operation? Did it rock back and forth or just drop down and stay down?

I'm going to try 30 # and see how it feels in the bus.

[dmatz]

It rocked around and was very apparent inside the coach, much louder. I was able to place a few pieces of plywood with rubber mat in between drilled holes to accommodate the mounting plug the air line till the new bag arrived. When the gen is off you should hear the air coming out of the bag if it's leaking or spray them with soap.

[JIM CHALOUPKA]

What I have. OH yeah the stainless is purposely dulled so as not to blind the viewer.

9248

JIM :cool:

[JIM KELLER]

Good One Jim !

[mike kerley]

Thanks guys, Its nice and dark in the area where my guage is mounted, so I'll not bother with a picture.....

[Reagan Sirmons]

You did a good job of dulling.
Pres

[jimshoen]

My Power Tech 20 KW is set at 30 PSI all four. 30 PSI is the Marathon spec on this coach.

[Loc]

The rear air bags are set at 29 psi and the fronts at 24 psi. I spent a fair amount of time with the pressures to get the quietest operation of the generator. Anything higher or lower results in significantly higher db inside and outside the coach.

[JIM KELLER]

Loc, I didn't realize you were so High Tech. I think I will try your numbers.

[mike kerley]

Thanks again, guys. I guess the next time I'm visiting Jim's famous "KKK", I'll have to attempt to set up a seperate maifold for the rear bags so I can have different settings. For now, I may just drop it on isolator blocks and see what the noise/vibration is like.

[Pete]

Loc only deals in MILLIONS! not pounds'

[grantracy]

Where is regulator and pressure gauge located ?

[GDeen]

Loc only deals in MILLIONS! not pounds'

Make that Billions Pete....

[Pete]

Sorry, I forgot about the inflation factor!

[JIM KELLER]

Granvil, Usually in the Generator Bay in some hard to read location.

[grantracy]

Of course,why did I ask..

[JIM KELLER]

It wouldn't make any sense to have this information conveniently located next to all the other generator information inside the Bus on the generator control panel !