[Archived]

I have zero clue as to what the Thomas pump is for unless it is for awnings. Do you have the Zip Dee automatic awnings with arms?

The 120V air compressor feeds the Prevost accessory air tank via the manifold that is installed by Liberty for its house systems. A word of caution….The only protection you have against moisture from the compressor migrating into the accessory tank is the “spitter” device which is supposed to automatically purge water from the line between the compressor and the manifold. That device needs to be checked and serviced often, and I would suggest you add a water trap or some form of air dryer in its place.

The noise is a standard feature. The 120V air compressor will make a lot of noise and rattle a lot but does tend to keep on working. A new one of the same type is only slightly quieter. If it is offensive you might wish to try a different one, but space might be a consideration.

If you are going to be at Lakeland, the maintenance seminar or Oysterfest I can show you in detail how I dealt with moisture.

[Andre]

If it does have a air zip dee awning it will have its own air compressor and air tank for awning and that’s all it’s for the awning

[Archived]

Andre, you have the dreaded Zip-Dee air/electric awning. Geo.

[Andre]

Thanks all,

Yes, we have the dreaded Zip-Dee air/electric awning. So I guess the Thomas compressor is for that. The awning does work, at least right now. I do have a little experince helping others with thier Zipp-Dee so I am not totaly in the dark on how it works or doesn’t work.

Jon, we will be at Lakeland in Feb., so I would like to see your setup for dealing with moisture.

[Jim/Chris]

Excellent. Anyone else is welcome also, but keep in mind my approach may be Liberty specific however the principle will be universal.

[Mike]

Andre just install a norgren water trap like the one prevost has in the steering bay the black one , just before the spitter cup as the aux compressor line comes into the steering bay to go into the spitter cup you can do away with the spitter cup the water trap will take its place and that way there will be no air pressure to the water trap when the compressor is not running that way it can not leak air because the versa valve shuts the air off going back to the water trap and to the compressor, but you will have to drain it manually, this way the norgren water trap will not be a problem with leaking because they are known to leak around the bowl or the o ring on the bowl

[Archived]

Jon, would you please post a pic of ur set up. I am interested in changing to a manually drained water filter for the aux air input also. Maybe others would be too. I’m inclined to get one like on our shop air since it works so well, but always open to something better. Thanks.

[Fred F.]

A picture will not help. All the air hoses look the same.

Here is what I did. First I removed what Liberty installed. They come out of the compressor to a solenoid valve that opens when the compressor runs, and closes when it shuts off. That valve functions as a check valve to prevent air from migrating back through the compressor and leaks to atmosphere. They also have a “spitter” in line also. Both are removed and I now go from the compressor directly through a Norgren water trap like the one inside the door that Prevost installs.

From the trap I go through a check valve into a manifold similar to what Liberty installs. The manifold has all the Liberty house pneumatic functions, plus one line feeds back to the Prevost accessory air tank. When the accessory system is charged that is the source of air pressure for the house functions. When the pressure drops the compressor kicks on, goes through the water trap, into the check valve to the manifold, and from the manifold back into the accessory air tank.

Does that help? The hard part is identifying the air lines and verifying their source and where they go.

[AL]

Yes got it, well done, thanks.

[Fred F.]

Forgot to mention the air supply for the pressure switch comes off the manifold because the line where I think it was originally installed was ahead of the check valve and that line pressure goes to zero quickly because as Peter mentions the Norgren water trap bowl seal is notorious for leaking.

It is far easier for me to explain at the coach so if you are coming to the events I listed above I can show you.

[Kirby]

Like to but our flexibility is still not flexible. That will change at the end of the school year when Barb is done ( 45 years in the classroom).

[Andy]

Dan find the air line that comes in from the compressor then put the norgren water trap there just before the spitter cup you can leave the spitter cup or take it out I would put a ball valve shut off after the water trap or before the water trap just In case the versa valve fails so air can not make it to the norgren water trap or the compressor just order one from prevost of the same size as the one they put in the steering bay

[AL]

I don’t see a versa valve in the line coming from the aux compressor on our vintage. From the compressor, the first device the line comes to is the spitter, then a pressure switch or valve that has two blue wires coming out of it that go into the well pump switch, then the well pump switch itself. Is this pressure switch with the two blue wires the versa valve you refer to (Jon)? I have changed the versa valve for the floor slide, tank dump, and grey water bypass, and none of them looked like this one.

In the past I had a leak at the joint between that 1 foot copper line coming out of the compressor that changed to a plastic line(the copper is probably to take the heat next to and in the compressor box). The vibration of the compressor transmitted through the copper line made the coupling loosen and leak which made the compressor run constantly. Put some blue locktite on the coupling – works. Seems like the leak at that joint should not have made the compressor run if a check valve is installed after that joint. So if that two blue wire thing is supposed to be a check valve … Or maybe we consumed aux air, then when the compressor kicked on, the leak was so great that it could never reach the cut out pressure set in the well pump switch.

My intuition is that the following sequence is what I want:

Compressor – Norgren trap – Check valve – Manual ball valve – Well pump switch.

Regarding that Norgren Trap that Prevost installs just inside the steering compartment door, I have never gotten water out of it, should I?

[Archived]

The Norgen trap as installed by Prevost adds no value. That is just an opinion of mine. When I got my coach sometime in its past someone got creative and modified the air lines and air flow path, leaving the Norgren trap disconnected. I seized the opportunity to use it for the house accessory air compressor water trap and I can tell you for sure that with about 15 feet of plastic air line plus the previously mentioned short copper tubing the trap will accumulate a fari amount of moisture from the compressor.

Dan’s sequence of devices is one I agree with. I think what Peter is calling a Versa Valve is the solenoid valve that is energized when the compressor is from the well pump switch. I removed it because if it fails while parked you lose air pressure to the house unless you restart the coach engine to build air.

The spitter to me is a high maintenance item prone to failure from corrosion or neglect. I saw no benefit to retaining it.

[Dorel]

You got the sequence of things right on Dan , the water trap takes the place of the spitter cup the check valve takes the place of the soleniod valve and the ball valve is just for safety if anything fails