The Generator Thread

[Just Plain Jeff]

Of the many components on a conversion, there are few items which are more integrally installed on a coach than the generator. Alas, however, the generator usually gets the last bit of attention from most of us; PDI and general maintenance.

But when we want it to work, it better.

Therein is the conflict.

The generator on a Prevost conversion can be anything between a 12.5 to 20Kw unit, usually powered by a Yanmar diesel engine. It uses the air system for the little airbags, powered off the main fuel tank, hooks into the transfer switch. It has a compact location on most coaches. In many cases, depending upon the conversion, may have a remote radiator, have a GENSET for automatic start, its own exhaust system and so on.

For coaches prior to 1992 (little known trivia item) the grounding systems in coaches is quite different than the post-1992 RVIA standard coaches. Upgrades must include a hardwired ground from the shore line to the transfer switch, main 100 panel AND generator.

So, there's a bit of general information to kick things off if you wish.

[Coloradobus]

I have been trying to find products to quiet the external noise ( not much there, but I want more) the generator emits. Marathon was using a egg-shell foam with a leaded material imbedded in it. They no longer us this, but I did identify the manufacturer. A 54in X 54in sheet( 27 lbs) was going to cost me $75.00 Bucks! (BTW, what is a Lew Buck?):D
We don't have a sound box like country Coach or Liberty, and ever since we heard the Fisher/Panda Genset in a 2002 Millennium (which was silent) I have a aspirations of the same quiet for our Kohler/Yanmar set-up. OUr former 2002 coach got a new generator before we traded. While the genset was out, I added an additional layer of this eggshell lead foam to the walls and door. Adding more mass DID make a difference our ears could tell.

[Jon Wehrenberg]

At the risk of stating the obvious it might be worthwhile when around other coaches to listen to their generators and then copy some of the ideas from those who make quiet ones.

Vantare makes a quiet generator box. Liberty does the same box within a box (Mike Guth who started Vantare stole a lot of the good ideas from Liberty and improved upon some). I know from dealing with noise in some products I developed a long time ago that different materials are required to deal with certain frequencies.

One of the problems all converters face is that they can truly kill all noise, but then they have no venting of excess heat or fumes from around the generator. All generator enclosures need forced air ventilation and that is a path for noise. Liberty and others remotely locate the radiator and the fan required to provide a flow of cool air is another noise source. Both of those noise sources need a convoluted sound deadened path it total silence is your goal.

The last and easiest source of sound is the exhaust pipe. I have a long convoluted exhaust pipe with a conventional muffler, a glasspack type muffler, and rubber straps on all hangers to minimize sound and vibrations from the coach.

If you really want to win the bling contest (not likely, but lets pretend) make your Generator real quiet, but the thing that will cinch the deal is to make a Webasto quieter than a 747 on climbout.

[Coloradobus]

Hey Jon,

Our Webasto is fairly quiet. Its the pump's whine that is noisy, but no bad. We also have a convoluted exhaust system on our genset with a pipe out the rear. I wished it had gone out the roof, but the PO ordered it out the rear. Our radiator is mid-body first bay. There is small amount of noise from that area but not much. The generator's muffler is inside the bay. I have considered doing the grass skirt thing around the coach sides like Vantate "H"'s but haven't. Chris said it makes the bus look like a UPS trailer wheelwell.
The only good idea is to switch out gensets for a Fischer/Panda where the bottom are of the genset/exhaust is in a water jacket and the radiator is on the roof with roof exhaust as well. Gee, shopping for another coach???? Nope!!!

[Jon Wehrenberg]

CObus,

I'm going to steal your Webasto set up. Mine whines and sounds like a blowtorch at the same time and like you said the circulating pump also contributes to the noise level.

The generator is likely as good as can reasonably be expected because when it is running along with a cruise air or two the cruise airs make the most noise by far. That is the condenser unit fans that we hear outside.

I'm too busy locking up the bling award to worry about noise right now. My focus is on bling.