SMC Discussion Areas

Trouble-Shooting => Refrigeration => Topic started by: on August 14, 2006, 01:06:30 pm



Title: Uss-8-64 - kerchunk
Post by: on August 14, 2006, 01:06:30 pm
I've got a USS-8-64 machine and absolutely love it.  I recovered it from the fire department as they were about to pitch it in the trash.  It just needed a good bath, and fresh paint.   It runs ice cold and has been humming along in my garage for about 3 years now.

The only problem I have, and have had since the beginning, is that the compressor is noisy when it starts/stops.   It runs quiet when it's on and it keeps everything very cold.  But when it turns on or off ... KerCHUNK .... it sounds like you dropped a bowling ball inside the machine.

Suggestions?


Title: Uss-8-64 - kerchunk
Post by: Jim on August 14, 2006, 08:33:45 pm
Depending on the refrigeration system, there may be some rubber bushings that could be missing. These mount the compressor to the compressor deck itself and insulate the compressor from vibrations during start-up/stopping and normal operation...
Older systems actually had springs that supported/mouted the compressor to the deck.


Title: Uss-8-64 - kerchunk
Post by: on August 14, 2006, 10:14:52 pm
I'll check, but I remember seeing those.   I'll make sure there's not one missing or something.


Title: Uss-8-64 - kerchunk
Post by: globalcompressors on August 15, 2006, 08:55:25 am
On the inside of the compressor can, the compressor itself is mounted on springs
and brackets. If it's a USS, it probably has a Tecumseh AE model compressor which has a 2 spring mount. Over time, these springs can break, cocking the compressor block to one side. The springs can break from trying to shake the machine, pushing up then dropping, moving the machine being heavy handed, dropping the machine, or laying it down during transport. The block sits vertical with the weight and gravity pushing downward on to the springs. Usually when one breaks, you get that "KER-KLUNCK" sound on stop and start up. That's the block hitting the inside of the can. When both finally break, then the compressor is sitting on the bottom of the can. At that point, the unit will eventually stop cooling because of the pressure on the discharge line being too great and breaking it.  :(

Eric


Title: Uss-8-64 - kerchunk
Post by: on August 15, 2006, 12:06:50 pm
Eric, you are the man!   I'll look at that as soon as I get home.


Title: Uss-8-64 - kerchunk
Post by: globalcompressors on August 15, 2006, 05:58:58 pm
Remember,  we're talking the compressor itself. The block is inside the "welded" compressor can. If you gently shake the compressor, with your hand, you can hear the block hit inside, kinda like shaking a coconut. It's only a matter of time before it breaks. One upside thing though, I have seen them run several years in this condition, if the machine isn't moved or shaken causing more stress.

Eric :)


Title: Uss-8-64 - kerchunk
Post by: rogerz on August 16, 2006, 01:09:13 am
So nothing can be done to fix them? Just a wait and see how long it lasts?

rz


Title: Uss-8-64 - kerchunk
Post by: globalcompressors on August 16, 2006, 06:37:56 pm
That's correct.

Back in another life, I used to rebuild "hermetic" compressors. When we quit and scrapped everything out, we wound up with about
425,000 lbs of scrap metal, aluminum, and copper. All compressors are basiclly the same, even up to 100 ton
screw compressors. Without cutting the machine open, building/repairing, and rewelding closed, you're out of luck. Enjoy it for now, when it fails, get the system rebuilt!


Eric   :)