Would you have expected this ???

[Ray Davis]

So, as per another thread, I had been getting ready for a trip. Sort of a test run was run this last week, where I drove from CA to Salt Lake City and back. Total about 9 days gone.

Other than issues I'd mentioned previously about malfunctioning Country Coach control board (which their tech is working with me on remotely!), things had been relatively calm, that is until the drive home yesterday.

So, yesterday we left SLC Utah at about 1PM, deciding to spend the night in Vegas. Just before coming up on this trip I had Prevost service my air conditioners. The dash air had a couple of leaks, which were supposedly fixed, and the proclaimed all the cruise airs to be fine.

Trip out, no problem. But we start home yesterday, and about 3 and 1/2 hours in I'm thinking, man this trip has really gone well. Bus is running well, and I got good mileage etc.

And then the dash air, which was getting warmer and warmer by the day quits altogether. A little while later I notice I have a low/high battery warning light. Bettery status indicated 13v on the 12 side, and 26 on the 24v side. I'm thinking genally the 24 is running at 28, but perhaps it's just hot. It really IS hot outside, and because the dash isn't cutting it, I'm running the generator and the cruiseairs.

Well, to make a long story somewhat short. ALL three cruiseairs stop working. I'm looking over at the generator control panel, and the amperage which is normally about 15 amp on one leg (bedroom air), and 35-45 on the other leg (front and mid cruise airs), are all reading near zero, and starting to blow warm air.

I turn them off, and make it to Vegas a couple of hours later, and it's 100 degrees there at 9PM. We'll to try to finish this, the cruiseairs won't re-engage until about 1AM, where I'm finally able to get the two front systems to somewhat cool the overly hot coach.

In checking the oil, I notice why the dash failed, AND the low voltage light came on, the dash condensor froze up, taking out both belts, so now I have no dash air, and no alternator for the 24v system.

So, we choose to get up at 5AM, and get out while it's relatively cool. I chose to cycle the airs, running each for no more than 30 minutes, with a 15 minutes every hour to cool the generator.

We make it home from Vegas fine doing that, however, by the 3rd cycle through all of this, the cruiseairs are shutting off again after about 15 minutes of working. That hadn't been on for more than a total of 1.5 hours apiece this morning, with gaps of 30 minutes between usage.

SO, I'm thinking this is my fault, I should have never travelled in the heat of the day, expecting air condition to work, especially since I'd just paid a lot to have it serviced, and proclaimed OK.

My neighbor, when I mention the trip to him tells me he would have expected that airs should work, and that this failure where all 4 air conditioners on my bus failed, is NOT expected, or acceptable.

So, I ask the masses, should you expect cruiseairs to shutdown like this when it's hot (and you need them most)??

Ray

ps: The cruiseairs all seem to blow cold this evening, and I ran them for about 30 minutes, and they didn't shut down, but it's only about 80 our here now.

pps: tag above the dash air compressor indicates the cooling system had been filled with R114 (I think that's what it said, label is hard to read. Indicating it was a R12 replacement). Work order from Prevost, I think indicates they filled with R12. Is there a problem mixing these two? Wouldn't (if there were something else in the system), have different connections for the coolant?

I know it wasn't R34, but I think it said R114.

[dalej]

Ray all the Cruise Airs have sight glasses that should be running clear after you run the air for 5 min. or so. I just checked mine since we are heading out this week. I would start by checking them out.

Our bus air...we changed from r12 to 134a so don't know what to tell you about your bus air. it sound like there are so many people doing different changes to r12 hard to know. Sometimes I'm tempted to just jerk out my hoses and start over, but as long as I get cold air for a few weeks in the summer I think its easier to put off, I had just added a few more cans of
134a to the system, it must have a slow leak somewhere.

The only other thing on the cruise air is to see how it passes air thru the coils, if while you are running down the road your now getting good air flow you will now get cool air. I can only assume that the install thought of that, but its now always the case.

[Jon Wehrenberg]

Ray,

My buses are OTR air buses so my experience is limited to the rare occasions when I have tried to run cruise airs while driving.

It has been my observation (and the basis for my personal requirement for OTR) that cruise airs powered either by inverters or generators are not suitable when driving on very hot pavement. When my OTR was acting up I was forced to resort to using cruise airs while travelling, and with the high outside temperatures they acted exactly as you described. As near as I could determine the problem was they were not getting enough cool air flow over the condensing coils. The heat radiating from the road surface had to have been considerable given that the outside temperatures were in the mid to high nineties.

As soon as the sun went down, the cruise airs went back to functioning as normal because the outside tempertures were coming down.

The cruise airs work fine when sitting in an RV park because the air being pulled into the condensers is ambient. The ground under the coach is not heated by the sun.

This is only an opinion and others who do not have OTR should post their experiences.

BTW, this is a strong justification for roof airs as an alternative to OTR.

[Jerry Winchester]

Ray,

I have used the Cruisairs running down the road, but they don't function very well. They blow plenty cold air sitting still, but I think Jon is right about the heat and the lack of airflow across the condenser coils.

I had a near similar thing happen at the end of our last trip. Everything was going fine, bus had been humming along lulling me into a sense of false security when the OTR AC fault light came on. I knew what it was and pulled over to reset the condenser blower motor circuit breaker. This scene was replayed several times during the day, but the frustration was still the same.

[Ray Davis]

Thanks for the notes. That's a bit concerning as the bus is scheduled to leave this Sunday heading from CA down I-10 through TX to FLA and then up to New York, and there's going to be a lot of hot areas.

Hopefully I can easily get the dash air fixed, but I need to use the cruise airs to supplement. I'm starting to think roof airs would have been a better choice?

Does anyone know whether mixing R12 and R114 is OK?

[ken&ellen]

Jerry & Ray, I have had positive results running my units while in route to Fla. as well as North & South Carolina. Of course we have not hit the triple digit temps that I have seen on the Weather Channel in the South West and West Coast. Good news Ray, you should be able to turn those units off when you get to New York.:D I lived in upstate NY for over 52 years and rarely had to use my AC units. Enjoy your trip. Ken

[Jerry Winchester]

Makes me glad I have coach air rather than dash air. You can hang beef in our coach even when the outside air temp is 110. I know it eats some HP up and I know you have to maintain it, but I would rather have the girls howling about how cold it is than about how hot it is.

And to Ken's note, I have run the Cruisairs going down the road and when it is not blistering hot, they cool good enough. But we had an OTR AC problem on the Phoenix to Houston stretch and the Cruisairs were humped up and not getting there. It was 117 when we left Phoenix, so it was abnormally hot even for there.

[Jerry Winchester]

Oh, I forgot this part. Ray, I don't think they mix.

Refrigerant
No. Name Molecular Mass Boiling point Freezing Point Temperature Specific Volume

R-11 Trichlorofluoromethane1) 137.38 75 -168 388 640 0.0289
R-12 Dichlorodifluoromethane2) 120.93 -22 -252 234 597 0.0287
R-13 Chlorotrifluoromethane 104.47 -115 -294 84 561 0.0277
R-13B1 Bromotrifluoromethane 148.93 -72 -270 153 575 0.0215
R-14 Tetrafluoromethane (Carbon tetrafluoride) 88.01 -198 -299 -50 543 0.0256
R-22 Chlorodifluoromethane3) 86.48 -41 -256 205 722 0.0305
R-40 Chloromethane 50.49 -12 -144 290 969 0.0454
R-113 Trichlorotrifluoroethane4) 187.39 118 -31 417 499 0.0278
R-114 1,2-dichloro-1,1,2,2-tetrafluoroethane 170.94 39 -137 294 473 0.0275
R-115 Chloropentafluoroethane 154.48 -38 -159 176 458 0.0261
R-123 Dichlorotrifluoroethane5) 152.93 82 -161 363 533
R-134a Tetrafluoroethane6) 102.03 -15 -142 214 590 0.0290
R-142b 1-chloro-1,1-difluoroethane 100.50 14 -204 279 598 0.0368
R-170 Ethane 30.07 -128 -297 90 710 0.0830
R-290 Propane 44.10 -44 -306 206 617 0.0728
RC-318 Octafluorocyclobutane 200.04 22 -43 240 404 0.0258
R-500 Dichlorodifluoromethane/ Difluoroethane7) 99.31 -28 -254 222 642 0.0323
R-502 Chlorodifluoromethane/ Chloropentafluoroethane 111.63 -50 180 591 0.0286
R-503 Chlorotrifluoromethane/ Trifluoromethane 87.50 -128 67 607 0.0326
R-600 Butane 58.13 31 -217 306 551 0.0702
R-600a Isobutane 58.13 11 -256 275 529 0.0725
R-611 Methyl formate 60.05 89 -146 417 870 0.0459
R-717 Ammonia 17.03 -28 -108 271 1657 0.0680
R-744 Carbon Dioxide 44.01 -109 -70 88 1070 0.0342
R-764 Sulfur Dioxide 64.07 14 -104 316 1143 0.0306
R-1150 Ethylene 28.05 -155 -272 49 742 0.0700
R-1270 Propylene 42.09 -54 -301 197 670 0.0720

http://www.engineeringtoolbox.com/refrigerants-d_902.html

[Ray Davis]

Anyone want to speculate on what would happen if you put R12 in a system which was previously filled with R114? You should see my AC compressor. It's a mess, frozen solid. Looks like a bomb went off!

[Just Plain Jeff]

In R12 and 134a there is a small amount of lubricant in the refrigerant itself. I don't know about 114, but if there was no lubricant in system, the effect may indeed have been detrimental to the compressor, assuming that there was oil in the reservoir (for the Carrier compressor).