CVC 374 cooling question

[paulheels]

I have a CVC 374, its a monster machine.  It cools well, but the thermostat does not seem to be working.  I dont know much about these things.  I just put a thermometer in it and it was on about 52. gonna check it in the morning to see.  I have the therm on level 6, i figured it should be near freezing at the level.   I just need some tips pr advice on what to look for pr what to do.  you are talking to a new guy here to, who is not to handy with electricity and stuff.  If ya need help growing a garden or coking meat let me know, I can repay info that wya..... haha

Paul

[MoonDawg]

        A faulty thermostat will freeze everything. Your machine may not be cooling down low
enough for the T/S to activate...........so you may have a compressor problem.
        I'll take my steak medium rare 

[paulheels]

 thanks, but that is not enough info for a steak and I did not say I would cook, jut I would give the instruction!  What do I need to look for on the compressor?  Dont want to spend money for someone else to come do it, if I can do something myself.  Also I am trying to learn, what are things I should look for, should I test?

Thanks
Paul

[paulheels]

Thermometer has been in there 24 hrs and it i reading 48 degrees.  just let me know what some things are that i  can look at .  appreciate it

Paul

[paulheels]

Anyone got any help for me?

[johnieG]

the ChoiceVend machines usually have multiple evaporator (air-circulating) fans behind the vending racks, the type they used are pretty cheap open-framed style motors ( think of the guts of a cheap bathroom exhaust fan) so I'd check to make sure that all of them are working & not gummed up with dust.

[paulheels]

thank for the help.  i quickly looked before going to work.  Looks like i am going to have to take all the drinks out and pull out the adjusters to look in there.  still gonna be kind of tight.  nothing is freezing anywhere on the machine and the compressor is in good shape.  it actually looks like a newer compressor.  thanks for the help, and if you can think of any other tips or ideas pleae let me know.

Thanks paul

[paulheels]

JohnieG!!!!!!!!!!!!  Thanks man, you hit it on the head.  They were fairly gummed up and only one was barely turning.  I am also missing one.  So I took them all off and sprayed the dust off with air hose and put them back on.  Nothing happened any different, so I am guessing that they are all pretty much shot. 

Where can I find a wiring diagram for the fans as well, I have them labeled, but that does not mean they might not be wired correctly before I got the machine. 

Also where can I find the fans?  I googled the fan that I could read, it was Alliance MFG model ISU 4.  One of the fans is different than the other two, looks to e a little newer, it is the only one running (not good though)

also, when i got the guts out there was some pretty heavy freezing on the left side of condenser, where the fan is missing. 

[collecture]

Can you post a picture of your fan? I just parted out a CV and have two of the fans - I don't know if they work, but I can check.
You might just try Home Depot or Lowes - just scavenge the fan unit from a bathroom exhaust fan like johnnie suggested.

[paulheels]

Collecture, here is the pic.  if you can not see it, there is a post in the post 1960 machines I started and there is a link there with a good picture.  Thankwell i tried to post but dont know how to post pics.  you can see the pic on the thread I spoke of earlier.  thanks for the help

[paulheels]

Thanks for all the help everyone.  I ordered the fans  and installed three of the fours, got to make a bracket for the fourth one.  Turned on the machine and they run great.  After three days i noticed that the compressor was not shutting off.  Hte temp varies between 36 and 38 degrees, there is frost buildup on the evaporator .  No ice and not 100 percent coverage of frost.  Before installing the evaporator fans, the compressor would shut off.   the temp would not get below 48 degrees.   

What is the deal here.  I have read many post and my conlcusion is the Thermostat, with the possibility of the freon being low. anyone got any other ideas ot ways to begin trouble shooting?

Thanks

Paul

[paulheels]

anyone got anything for me?

thanks

Paul

[johnieG]

Assuming it's an air-sensing type thermostat, then either you've disturbed the position of the thermostats sensing tip ( it's not directly in the cold air stream) or you have it set too cold, or it's a bad thermostat.

If it's a direct contact type, then make sure it's clamped snuggly ( but don't go gorilla & crush the tubing) to the evaporator preferably nearest the capillary tube side of the evaporator. or it may be the type that slides into a small tube that runs through the evaporator core.

if you've disturbed the capillary tubing or sensing tip of the thermostat, make sure you didn't kink it, at which point you'll be looking for a new one.

[paulheels]

New update on the cooling problem.  Not solved yet, but  gaining ground, thanks to all qho have helped.  just need a little more guidance.  Here are the new things.  The thermostat probe is a contact probe.  it slides into a copper tube on the side of the evaporator.  the end of the probe has a spring, it is heavily coated with old grease, should that be clean or is that some type of contat adhesive?  I made sure to push the wire as far as i could without crimping. 

  I turned the thermostat on and let it cool.  it cooled down to about 34-36 degrees but never !%@$ off.  i had it set on the lowest setting, and it run for aobut 12 hours.  It never shut off.  also, once it started cooling there was immediate frost buildup on the evaporator.  I live in South Carolina, in Aiken, and it is very humid, thought that might be part of the problem.  Maybe it needs charging? 
  I am beginning to think that the therm is bad.  let me know what yall think.

I appreciate all the help, yall are a great resource.  Paul

[johnieG]

replace the thermostat.

[paulheels]

thanks Johnnie G.  straight to the point!  have done alot of looking online for another therm, nothing seems to be coming up that resembles mine.  The part is a Cutler-Hammerpart num 9531n181

Paul

[Brownac1983]

I have a CVC-224, which seems very similar to what you described. I'm also working out some refrigeration issues, with a swap over to R-134. My machine would not cool when I got it and I narrowed it down to a sealed system problem. I tapped in and found that there was no static pressure, so basically my sealed system was not sealed anymore. I evacuated and recharged with Hotshot. I could only get the temp down to 40 degrees, with the compressor running constantly. I took pressure readings and my compressor was only making around 100PSI. I couldn't find any specific specs, but figured that the pressure was not high enough for good cooling by comparing it to specs of similar systems. I got a R-134a compressor from a refrigerator and brazed it in. I flushed all the tubing to remove any old oil. I put in a new drier and charged with R-134a. I fired it up and found out where my R-12 had gone. The condenser outlet where the tube makes a 90 degree bend and goes into the drier was leaking through a hairline crack in the tube. The increase in pressure with the new compressor was enough to really open it up. The tube appeared to be steel. I brazed it up and recharged and it was cooling great. Unfortunately, I didn't have time to get the charge right because I had to go out of town the next day. Sorry to be lengthy, but check the area I mentioned for any evidence of leakage and maybe sand off the paint and check for cracks. My thoughts are that your evaporator was getting cold enough to trip the thermostat before you fixed the fans. Now that they are running, they are transferring heat from the cabinet to the evaporator like they are supposed to, and now your evaporator won't get cold enough to trip the thermostat because for whatever reason your sealed system can't get it there.