I went to a call tonite, small cooler in restaurant, owner unplugged it, says evaporator section froze up. I hook my gauges up plug unit in compressor starts, pulls down to 3 psi over 98 psi, cap tube is colder than compressor suction line at compressor. All this tells me unit is low on refrigerant. This is an old Jordon cooler, problem is I can't find any data on it telling me what kind of refrigerant, I susspect R12, I could be wrong. When I took refrigerant pressure readings, cooler ambient was 68 degrees, I'm not even sure what the set point temp is suppose to be. Anyone ever seen an old Jordon cooler? please help. If the defrost control is bad, can I replace with after market, I dought I can find oem part. When I first plugged unit in compressor started no problem, then I unplugged it for a few minuets, and plugged it back in, compressor did not start, evap fan runs, so I think when you cycle the power it resets the defrost timer.
[Edited by flangehead on 05-16-2004 at 10:34 PM]
If the compressor didn't have a start capacitor [only a current relay] then you may have needed to let the pressures equalize some more before re-energizing it. On cap tube boxes like that, you have to let them run a while before making a determination about operating pressures/temps. Most likely, it was originally R-12. Perhaps you can use the compressor model number to figure out the refrigerant type. Post it here along with brand name. Just about all the refrigeration system parts should be replacable with aftermarket. Normally, a reach in box like that will use a constant cut in type thermostat with the sensing element buried in the evaporator coil. The cut out temperature is adjustable but the cut in temperature is fixed at usually 38Ί to 41Ί. Translation- every off cycle is a defrost cycle. First thing to check on those is to see if someone set the t-stat as cold as it will go which causes the compreaaor to never shut off and freeze the coil over. If you find yourself working on a lot of these types of boxes, get some catalogs. Examples- SUPCO, GEM, Franklin Machine, Uniline, etc. Also, look at Perless and Heatcraft to see what's available for replacement evap coils. Ditto with Tecumseh and Copeland for compressors and condensing units.
Hey Flange ... your gonna need to determine real quickly if this box is even worth sinkin any dough into.
Feel out this customer. Find out how attached to this machine he is.
Dont even tell me this is a Chineese Restaurant.
If it is, be honest, do what you can ... but be willing to simply and patiently ... walk away.
If it were my customer, I would first determine if the compressor valve were any good.
Next I would deal with the starting components.
I would trouble shoot the start cap, then the relay.
Make real sure you got decent power "AT THE UNIT" during start up. A long extension cord is NOT acceptable!
Make real sure he leaves you alone to make your diagnosis.
If they insist on looking over your shoulder or worse, HELPING YOU ..... get outa there FAST!!!
If you have an ANNIE, use it to diagnose your start problems.
You can purchase individual components in order to replace everything inthe start package. NON-OEM, of course.
You dont need "jack" from OEM on this old a project. Johnstone has EVERYTHING you need.
So far, you have kept the customer at bay, determined the unit sucks. (has good valves, pulls into a vacuum in good time), diagnosed the start circuit and made a list of what you need.
Now ... let's deal with the sealed system part of the project.
If you have a leak, you MUST determine where it exhists.
If it's in the evaporator .... kiss it goodbye.
Sure, it can be salvaged, we have all been there/ done that. But in reality, if yoiu got an evap leak, you got more than what you'll find on your first trip there.
So unless this customer dont have the money budgeted to maintain his equipment ... you will be buying a new eval coil for this project.
Then a drier, a good evac and recharge.
I guesstimate four hundred dollars, plus evaporator if you need one.
Did that help?
[Edited by R12rules on 05-17-2004 at 10:13 PM]
Good advice from others. If it's a 2 door upright I have a new evap. for it. Twin coil.
Be safe not fast. body parts don't grow back
Thanks alot guys the info is much appreciated, I'll check model number on compressor, if I decide to even go back. This could be a cheap non paying customer. Guys at sid harvey said unit is probably r-12 and I could retrofit to a refrigerant called Hot Shot. Thanks again