SMC Discussion Areas

My VMC has been running and cooling for the last 15 years and now all the sudden it won't cool below 45 degrees. The compressor kick on and off and both fans run. I blew all the dust bunnies out and played with the thermostat but it won't cool down anymore than 45 degrees where it used to get down to 35 degrees. Any ideas????

1) low Freon/leak in system
2) plugged filter/dryer/filter-sieve
3) plugged capillary tube
4) above items causing compressor's overload to trip/open
5) defective thermostat (fiddling wont help)
6) defective compressor/valves/no freon circulating in system

6) Happy New-Year

7) Welcome to the board!!
8) Any pics of the S-Ray to share :-)
Thanks,
Creighton

A thermostat replacement is the cheapest/easiest solution...
If you're diligent and handy, you could bypass the thermostat to see if the unit does cool down below 45, but remember to stay around and monitor as the compressor will continue to run until YOU shut it down by unplugging the machine ! ! !

my vmc 81 cooling unit

Another one ofmy VMC 81 cooling unit

I will try and bypassing the thermostat. Hope I don't' burn the house down. That will upset the wife !!!!!!

You do not have an original compressor assembly in your machine. Try Jim's suggestion of by-passing the T-stat first.

I think I see a clamp on schrader valve in the picture and that could be leaking freon.

WOW, not the right cooling unit!!!! I was assured it was "all original" when I bought it. OH  :down:Well, Newbie takes it in the shorts, (again).  Not sure about a clamp on schrader port but the freon fill port is welded on. I tried bypassing the thermostat and the compressor ran continuously without getting the inside temp any cooler (still about 45 degrees). Could it be something as simple as low freon charge? If so what do I service it with, R 12? And who could service it? I called a couple of appliance stores and they said they don't work on "vintage machines". Of course Tulsa isn't the hub of antiquities.

Could be low on freon. That would mean there is a leak which would need to be fixed. Shipping from Tulsa to Eric (Global Compressors) shouldn't be much. I give Eric a call before anything else. Listed under vendors.
Creighton

The unit is original...the compressor is not.
When the unit cools down to 45...does it shut off,
or keeps running and simply stalls out? If ir stalls,
and won't cool down further, probably low on
refrigerant...i.e. leak. If it shuts off at 45 degrees,
then... thermostat issue. Also, make sure both fans
are running.

The compressor will keep running with the thermostat turned to max cool but the temp never gets cooler than 45 degrees. Yes both fans are running. If I turn the thermostat down the compressor will stop running. Everything acts normal except it won't cool below 45.

I'd guess you have a leak and it's low on Freon...

A friend put his gauges on the low side and it showed only 40psi ( compressor running). Shouldn't this be a lot higher, up aroud 140 psi with compressor running?

Low side should be lower than that.. 28-32 maybe?

Interesting, no, it should be a bit lower, depending on which refrigerant gas is being used, ( R12/vs/R134 etc.) since we don't know what refrigerant it's using, it should be between 18 to 25 PSI on the low side near the evaporator on average, and less than approximately <150PSI on the high side . in a 70-degree room air temperature.

what is the running vs idle/off pressure on the low-side?  ( the "low-side" is the large diameter copper line leading away from the evaporator directly back down to the compressor) 

Sounds like you might have a compressor problem. As JohnieG said the low side or suction pressure should be a bit lower, if the condenser coil is clean and all fans are running the way they should, all shrouds are in place it's probably the valves in the compressor are leaking by. When the valves don't seat properly refrigerant leaks by creating a higher suction pressure and less performance and less cooling which will probably mean a new compressor. A good refrigeration service tech. should be able to determine what the problem is for sure.

I agree, I think it needs a new compressor. Any idea what and where I can get one? Would Eric at GlobalCompressor have what I need? I think I could put it in, but still haven't found anyone to service it with freon,especially R12.

Yes eric can square you away.  He is extremely helpful. 

I'm sure that Eric would have a compressor for you, he might have you send the whole system to him so that he can change it out and recharge the refrigerant, it will probably be 134A though.

Tried for several days to call Global Compressors and just got an answering machine. I found cooling units at Funtronics, anybody know about their quality?

I'm here...just taking time off.

I haven't been to the shop in several days, but I am answering emails...try that.
Most of the Guys around here, know that I work long and hard hours, and
that I have to have "down time". I take care of this in the Winter, because it's
my "slow time". I don't need to run 24/7 or I'll wind up with a bad case of "burn out".

Fun-Tronics is one of my distributers... the quality is the same...

Again, try an email...

Eric

Yohoo Eric!!! time to wake up and go back to work. I would never deprive a man of his time off but I'm going into D.T.s without my machine. The colas and beer taste awful cummin' outta a  common refrigerator. I need my vintage machine fix!!!!!  Let me know when you go back to the salt mine. :down: