So What's Going On Here? (Compressor not kicking on -- Videos)

[hoghopper]

Hello forum.  After waiting a while, I'm registered.  Glad to be here.

I have a Vendo 90 in Dr. Pepper kit, probably from the early 70s.  I used to run it, but it quit working so I left it alone.  Then about three years ago, I took the refrigeration unit out for a trade-school class to use as a hands-on repair project.  But it worked perfectly well for them, so I brought it home and re-installed it.  It ran fine for a few days, and then didn't.  It went back to what it had been doing, discussed below.

So I'm not getting any refrigeration.  Thermostat tells the compressor to start, but it just clicks (see video) and re-cycles.  What to do?

Couple of videos of the problem:

http://youtu.be/mh-MO44H85M

http://youtu.be/PwT9baCIDFA

[kbareit]

It appears it is kicking out on overload. You could just have a bad overload but the relay and capacitor could be bad also. I would replace all three with OEM parts if available, if not get a 3in1 cap relay overload kit. Just make sure it is rated for the HP of the compressor.

                                         Welcome to the forum, Ken 

[johnieG]

Most capillary systems in the 70's (especially soda machines) didn't have a start-assist cap' plus I don't see one mounted on the compressor, So, since the compressor doesn't even start before the overload kicks out, the compressors either sticky, or just plain stuck, (locked-up)

You should try a 3-in-1 and see if it breaks the compressor free, then you could try to reinstall the original start-run relay & overload, but I personally wouldn't bother as it's been stressed at this point & probably wouldn't be reliable anyway, take into consideration that this is a 30+ year old cooling deck & it may have just "retired" itself because of the compressor being bogged down with a sticky piston & drawing too much current, or now it's locked itself up.

Try a SUPCO  1/3-1/4 HP 3-in-1 booster/hard start unit, & if that doesn't work, it's time for a new compressor.

Another passing thought is that maybe a loose connection, but you never stated what they ( the HVAC students) did to revive it...just curious.  

[hoghopper]

Thanks for the good info and advice. I'm off to implement it.

[MrMark]

Are you running this unit off an extension cord? Have you checked the input voltage of the circuit the machine is plugged into while there is a load on it?

It almost sounds like it's an under voltage problem, that the students at the trade school did not have. JohnnieG is right, it could be the cap, but the Klixon overload is there for a reason, and that is the compressor won't start. I would measure the current (amps) while the compressor is trying to start to see if it's at locked rotor amps. If it is, you may have a locked up compressor, especially if the unit ever had, or has had then repaired, leak, and a lot of oil was lost.

Multiple simultaneous things could be the problem and each has to be investigated.