OTR A/C Tech question

[Joe Camper]

Kevin on a Prevost XL with the dash air from the factory the dryer is between the compressor and the condenser.

Nick that imbalance you refer to brings a question to mind. ALL the other a/c I have seen have 2 separate compressors. This coach is the first I have seen that has only 1. I was fairly confident this fact was going to complicate the project before I started it and I view your suggestion as confirmation of that fear.

Another thing I noticed. The sweat going on at the low side line at the compressor was nothing like it was at the evaporators and the extreme chill on those low side lines right there. Very little sweat and chill at the low line at the compressor ever developed when the evaps were very very cold and swetting.

When I recharge do you think it would be prudent to charge it with the high side solenoids open on 1 loop only and when it gets cool enough stop open the other loop and judge the performance at that point?

The compressor will be a week or two coming so I have some time to try to sort this out. The owner is wanting me to give up on the rear loop and just get the dash back on line. I am fairly confident that would eliminate another failure but I want it to work as designed, all of it. Guess im glutten for punnishment.

[Busted Knuckle]

Joe I am by far not an A/C expert. As a matter of fact I know what I know about A/C from trial & error working on my own stuff and I can testify I've had plenty of error.

But if all he wants is the dash A/C is sound to me that the compressor you have / are waiting for maybe too big for the job.

I have learned enough from my experiences and listening to others all this stuff has to be properly sized together to work right.
  BK   

[kevink1955]

Joe, thanks for the info on the dryer location. I wonder why they put it there, the more common location is at the condensor outlet.

Another thought I had is when the solinoid valves close where is the 13 lbs of refrigerant stored. Is there a large receiver, I could not see the condensor being able to hold all the liquid that will be evacuated from the evaperators when the solinoids are closed.

[prevosman]

Kevin on a Prevost XL with the dash air from the factory the dryer is between the compressor and the condenser.

No it is not. On a Prevost the dryer is after the condenser coil and ahead of the expansion valve. The sequence of components starting with the compresor is condenser coil, receiver, dryer, expansion valve, evaporator coil and return to the compressor. On a full bus system the sequence after the compressor is a check valve, condenser coil, receiver, a second loop through the condenser, dryer, dry eye, solenoid valve, the driver's air loop, evaporator coil and return to the compressor.

[luvrbus]

Joe is working on a CC they really never had factory dash unless the customer ordered it most of the time they just had the evaporator from the factory up front and they screwed the rest up he has his hands full I can tell you

good luck

[prevosman]

Unless someone other than CC modified the entire system, the driver's air as built and delivered by Prevost was as I described. When CC added their version of over the road air it was a self contained loop that did not join or in any way share any part of the driver's air loop.

If someone after the fact then joined both systems it was not Prevost or CC. When questions are asked regarding factory built coaches it is very difficult to provide complete correct answers because each vintage of coach may have variations from previous and subsequent models. When someone other than the converter or the shell manufacturer makes further undocumented alterations it is impossible for answers on a forum to be correct. I should have qualified my remarks by emphasizing my answers were correct only in reference to how Prevost built it.

One thing that does not make sense is why a dryer would be in the system on a gas side of the condenser and not the liquid side. If in fact that is the case the entire system is suspect.

[luvrbus]

I don't what to tell you Jon I been to CC 100's of times even saw those guys installing a generic evaporator in the factory heat and defroster housing saw the installing of both compressors more than once when they belonged to National RV weird stuff went on there
Bob Lee was never able to bring the co back to life from National but he is giving it another go round lol and age is not on his side  
FWIW I have a friend in Neb that has a screwed up CC dash air in his 1997 model we finally got his working by installing 2 of the old Harrison A6 compressors been doing fine for 5 years now

good luck