upright cooler?

[KB Cool]

Old Traulsen upright. 2 yr old compressor locked up. Replaced compressor and dryer. Fired unit up found cap-tube restricted. "Should of changed it. when I changed compressor.....But it looked new and recently replaced and r-22".
Okay, changed cap-tube using chart 1/3 hp med temp. Went with 87 inches of BC2. pullled vac. fired unit back up box pulls down to 38. overload opens, compressor shuts off and feels HOT. Inspected all electrical connections, look good except outlet looked a little hot, So I changed outlets and Let unit cool. OL resets. start unit back up, ended up with 90 ambient,Box temp 30, 250 high, 30 low, 5 SC, 40 SH at compressor. Drawing 6.3 amps,which is the same as before when OL opened. Comp. model #ARE43C3-IAA-901. Told customer. I'll be back monday and go ahead and use box. But don't leave product in it overnight.
Why did my OL open? And do any of you guys see anything wrong with my pressures? Also I could see right throiugh condensor coil and appeared to have been cleaned recently. I know the cap tube box says, "actual length may need to be fine tuned". But how?
Thanks

[jamesgriffin]

Your pressures for 22..

30 low = 8 degrees evap
250 high = Roughly 118 condenser
40 degree suction line = 32 degrees superheat

you should be running about a 20 degree coil so your
numbers should be

low = 43 PSI
high= depends on ambient conditions but the rule of thump is your condensing temp should be around 30 degrees higher than ambient (condenser over ambient) If Room temp was 70 degrees... you should be running 100 degrees or 195 psi

So you are running low evap pressure, high superheat, and moderately high head pressures...

I would check for a liquid line restriction past the condenser...

The comp siezed up... did you flush the system? Personally I would remove the cap tupe... install a tXV... and sight glass along with another liquid line dryer... and an HH Acid Core drier on the Suction side.

I would of had to be there to determine why the new pump's OL tripped...
Hope the info helps...

[KB Cool]

Yes it does seem low. But the subcooling does not really fit a restriction. Or does it?
Thanks

[jamesgriffin]

Your SC does seem a little low... it should be around 10-15. I believe you have a restriction... somewhere .... check the liquid line for kinks... also check the temp of your liquid line on both sides of your drier... if there is a big difference in temp... the drier may be plugged. how much burnt oil could be in the system from the compressor burn out... causing restrictions...

un bolt the compressor ... flush that system then install your suction line drier... pull the system into a tight .... vacuum overnight is better... then weigh in the appropriate charge... and let her go... it is best to let the box reach temp before adjusting charge .... sometimes when the box goes into a hot pull down it is easy to assume ... and quickly over charge a system... not that it would ever happen to be .... anyways good luck.. I don't really like 22 for low temps..... 409a is about the best low temp gas you can get.....since 12 is no longer available.

[KB Cool]

I was Kind of wondering about the fine tuning of the cap tube. I am thinking I need to shorten it to allow more refrigerant flowing in the evap. Which may bring down head and allow me to add a little more juice. To me it seems like it just needs more juice. But the head is kind of up there already and due to the OL opening earlier. I did not want to push it. Maybe I'll go back tommorrow. And pull the dryer and shorten the cap tube a little and try again.

[k-fridge]

I think you're just a bit undercharged. The cap tube may be a little too long. Is this compressor the same as original? I wonder how well the capacity of the compressor matches the condenser. Suction is low, head is OK, just don't want to go much higher. SH is high and SC is low, that's why I think you're undercharged.

[KB Cool]

The compressor i put in is the same one I took out. I don't think the condensor is original to the unit. I kind of knew this thing was going to be a problem when I pulled the old pump and looked at the 05***** serial number on the compressor. I am really concerned with High head. Because this kitchen has no A/C and I expect tempatures in July and August to climb well above 100F. K fridge how much should I take off the cap tube in inches. To get my TD more in line.

[KB Cool]

There's something else I want to ask about. On a cooler with the discharge line acting as a condensate pan heater. I noticed if water is in the pan discharge psi will be lower. So my question is should I judge discharge pressure with or with out water:D

[k-fridge]

You're just guessing with the cap tube so I wouldn't go but a few inches. I'm thinking that your condenser may be on the small side. The head is not a problem now, what happens in the summer remains to be seen. I'm pretty sure you're undercharged but if you add more the head may go higher. Woulda been better to change the cond unit. I'd maybe try cutting 8" off the cap tube and charge until your SH is more in line. Get the unit close to temp and set SH about 10* at the evap, make sure it
s 20-30* at the compressor. SC should go up as well, maybe 15* or so.

[k-fridge]

There's something else I want to ask about. On a cooler with the discharge line acting as a condensate pan heater. I noticed if water is in the pan discharge psi will be lower. So my question is should I judge discharge pressure with or with out water:D
Since the water won't always be there, I wouldn't count on it.

[KB Cool]

Hey guys went back to the cooler saturday and felt the compressor. It was not all that HOT felt normal to me. Box was cold too.
My question is by adding gas to the suction with a full bottle of r-22 (probally 175 psi coming out of my hoses) cause my little compressor to get hot.
I normally dont add gas to these little things but rather weigh in the charge as a liquid and go. But when I don't have that info or the system has been altered should I throttle in the gas on the low side without pushing the suction to high and possibly overheating the compressor real quick:D

[idontgetit]

Hmmmmm

Worked on one of those single door traulsens 1/3 hp last week.

Cap tube required is a .036 at 46" R-12 unit

I have no idea if your bc2 fits that flow rate or not.

The original cap tube was soldered to suction line as a subcooler (kinda eliminates that modulating bubble theory that floats around this site so much) and you have to compensate minimally for that.