Auxiliary compressor for charging air system

[rv_safetyman]

As an alternative to a 12V or 120V compressor, I am in the process of designing a system to use a York AC compressor driven off the generator. 

Folks with air suspensions on cars or off road folks have done this for years.  I have one on my '56 Chevy which has air suspension.

For more information, you can go to:   http://www.kilbyenterprises.com/

A good story about this kind of system can be found at:  http://www.offroaders.com/info/tech-corner/project-cj7/project-cj7-onboard-air.htm

At engine idle, the compressor is said to put out a bit less than 4 CFM. 

My plan is to add another air tank with a pressure switch to operate the compressor when the generator is on (will include a shut off switch in series). 

I also have a belt driven hydraulic pump with an electric clutch that I am including in the design.  I will use that to operate my hydraulic jacks.

The belt drive is critical so that it does not load the crankshaft with belt pull when the compressor or pump are not working.  I have the worked out, but it is a long technical discussion. 

Just a thought.

Jim

[RichardEntrekin]

Newell uses a 120 AC compressor made by Gast to keep the air pressure up while camped. They also have a small 12V compressor that is plumbed to the toilet and pocket doors only via check valves so that you can flush the potty when you are dry camping. The switch for the 12V pump is in the bathroom.

Just wanted to give you guys somethings to evaluate as you engineer your systems. 

What ever aux compressor you use, please install a water trap at the compressor. If camped in a humid location, you can pump a lot of water in your system without realizing it.

[Sean]

Sean,

Were did you buy the Hitatchi and what did you pay?

Wow, John, I honestly don't remember very well.  It was a couple years ago at this point.  I'm going to guess that I bought it at Home Depot, in whatever town we were in when the Porter Cable crapped out.  I probably paid $250-$300 for it, having, by this time, given up on $100-$150 compressors.

It's a Hitachi EC119SA, and I misspoke earlier -- it's 2.5 horse, not 1.6.  If you Google for it you'll find it discounted in several places.

This is the best compressor I've ever owned, and I love it.  It has dual gauges (one for tank pressure and one for regulated pressure), a finely adjustable regulator, easy-open drain petcocks with hose barbs (I've plumbed them out the bottom of the coach with some vibyle tubing), and dual stainless universal chucks.  This last item is handy -- I have one chuck "plumbed" semi-permanently to the bus using a short section of hose with dual chuck fittings (the bus connection also has a universal chuck) and a ball valve, but the other chuck is easily accessible for my accessory hoses -- to fill the hot tub, inflatable boat, scooter tires,or whatever, or to blow the dirt out of the A/C filters.  It's also still light enough that I can disconnect the bus hose and take the compressor anywhere, including around the other side of the bus to top up a bus tire if needed (after first cranking the regulator all the way up).

The compressor runs off our inverter, and with less than a minute of run time every hour, the drain on the batteries is hardly noticeable, and, in fact, our solar panels are enough to keep both our fridge and the air compressor happy indefinitely, unless temps drop toward freezing (where air leaks cause more compressor run time).  Start-up current is high, though, and sometimes the compressor kicking on causes, of all things, the digital timer on the coffeemaker to lose its mind.  It's also a bit noisy -- we've got it buried in a bay behind Styrofoam insulation, which muffles it pretty well, but if I happen to have the bay door open, say because I am grilling (the pull-out grill lives in the same bay), I have to step away while it is running.

-Sean
http://ourodyssey.blogspot.com