Basement a/c question

richard5933 · May 26, 2018, 04:27:05 PM

We've got two basement a/c units, both installed by Custom Coach. They appear to be custom units, and I cannot find a name plate on them anywhere.

Set up on both is the same and simple. Compressor and condensing coil below. Evaporator and air circulation fan above. Wall switch turns on air circulation fan and controls speed. Line voltage thermostat turns compressor on/off as needed. Don't see circuit boards or other electronics anywhere.

Problem started today when we tried to cool off the bus running on generator. Front a/c will start up and run for a few minutes, maybe five. It blows plenty cold during that time. Then the compressor cycles off. Only way to get it to come back is to turn off the breaker and wait about five minutes and then start over.

The other a/c unit works fine and just keeps pumping out cold air. This unit has worked well till today when outside temperatures hit high 90s.

I have little experience with a/c systems, so I am looking for ideas on how to troubleshoot and what to look for. Since it blows cold for a while, I'm hoping that means that the compressor is still working. Hoping the same for the refrigerant.

Any suggestions?

DoubleEagle · May 26, 2018, 05:03:06 PM

On my 1984 Eagle Entertainer, the basement combo A/C-electric furnace is by MemphisAire, which is no longer in business, just like Custom Coach. I'm surprised that some details of your units are not mentioned in all of the documentation they provided. Fortunately, many of the components of the units are used in other brands, and a good A/C shop should be able to come up with equivalents. The previous owner of mine replaced the circulation fan motor by going to an electrical supply house and getting a replacement with the same specifications. You should have a thermostat control ideally, that will let you set a temperature to maintain.

I believe there was a post fairly recently that had said one of the former Custom Coach people had a bus sales/conversion business in Marion, Ohio (or maybe Mansfield, OH). If you could reach some of the former Custom Coach people, they might be able to help provide clues. Custom Coach was active into the late nineties, at least, but at some point, they sold out to Farber Specialty Vehicles and became the Custom Coach Division of Farber. They are in a different building now, which is visible off I70 in Columbus, Ohio. If they were smart, they would have retained some of the employees, and the records of previous coaches.

Geoff · May 26, 2018, 05:33:39 PM

It could be Cruise Air's I have a bus in my shop with front and rear units Cruise Air units. I haven't got to the point of testing them, but if they need fixing I do 'em.

TomC · May 26, 2018, 06:19:48 PM

Check to make sure your generator is putting out 60hz under load.

richard5933 · May 26, 2018, 06:43:02 PM

Quote from: TomC on May 26, 2018, 06:19:48 PM
Check to make sure your generator is putting out 60hz under load.

I'll check that. Is voltage as critical? Generator puts out 115, but with both a/c units running drops to 107.

thomasinnv · May 26, 2018, 07:10:36 PM

Quote from: richard5933 on May 26, 2018, 06:43:02 PM
I'll check that. Is voltage as critical? Generator puts out 115, but with both a/c units running drops to 107.

Most electrical items today are designed to run +/- 10% or more, older components usually right at the 10% margin, so safe range would be 108-132. If they are inverter technology the acceptable voltage range could have a much larger swing. I have one device that is rated to run from 90-140 volts.

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sledhead · May 27, 2018, 05:40:43 AM

make sure the fan on the cooling unit is working

dave

kyle4501 · May 27, 2018, 06:06:43 AM

Quote from: richard5933 on May 26, 2018, 06:43:02 PM
I'll check that. Is voltage as critical? Generator puts out 115, but with both a/c units running drops to 107.

107 seems low to me,
Low volts allows the unit to pull higher amperage which generates more heat.

lvmci · May 27, 2018, 06:25:26 AM

Hi Richard, try only running the one unit, that shuts off, alone and checking the voltage. If it runs longer or doesn't shut down, it's the electrical supply, if it shuts down about the same time, it's in the unit, lvmci...

thomasinnv · May 27, 2018, 06:33:43 AM

What make/model of generator? The no load voltage is a little low and may be adjustable depending on what you have. The hz is dependant on engine speed.

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richard5933 · May 27, 2018, 08:16:01 AM

Quote from: thomasinnv on May 27, 2018, 06:33:43 AM
What make/model of generator? The no load voltage is a little low and may be adjustable depending on what you have. The hz is dependant on engine speed.

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Kohler 12.5kw generator w/Perkins 4.108. I can find the specific model later if needed.

luvrbus · May 27, 2018, 08:27:49 AM

You have photos of your units if they are Cruisairs they can be touchy with starting because of the Freon charge too a photo of the controls will help if they are the Cruisiairs or not lol Cruisairs can be touchy a good unit but very temperamental at times

oldmansax · May 27, 2018, 08:35:13 AM

Quote from: richard5933 on May 27, 2018, 08:16:01 AM
Kohler 12.5kw generator w/Perkins 4.108. I can find the specific model later if needed.

Those generators were used extensively in Wanderlodges and there is a lot of info about them on the Wanderlodge Owners Group board. They are known for producing low voltage as they get older. That can usually be remedied by replacing the voltage regulator ($300). However, there are other maintenance concerns with the unit, including the rear main bearing, brushes and rings. People do the maintenance depending on the size of their pocketbook and level of expertise. A number of people have just replaced the generator head with the new brush-less type from Central Georgia Generator. I have done both and need to fix the one I have now. I'm going with the new had this time. The Perkins is a very durable engine and will run longer than you need it unless abused. The replacement of the gen head will give you a more powerful and reliable generator that will probably outlast the bus.

TOM

Oonrahnjay · May 27, 2018, 09:50:30 AM

Quote from: richard5933 on May 27, 2018, 08:16:01 AMKohler 12.5kw generator w/Perkins 4.108. I can find the specific model later if needed.

Only 107V from a 12.5k generator? Something is *very* wrong there. I'm glad that others have had experience with this unit and are helping.

A few years ago, someone sent me an entire CruiseAir manual, including tech specs, installation, circuit diagrams, etc. I scanned it to emailable files -- if your A/C turns out to be a CruiseAir and you don't have the manual, I'll be glad to send those files to you. Just let me know.

richard5933 · May 27, 2018, 10:24:35 AM

Voltage is being read at the analog meter over the driver. Could be different in the outlets.

We're on the road till Tuesday. My first thought for when we get home is to verify readings and then check connections end to end for anything loose or corroded.

Are the voltage regulators adjustable? If not, anyone have a reliable source?