Capillary Tube

[ascj]

I checked out a under counter refrigerator/freezer for a friend today. The company that normally takes care of his stuff said it won't hold a charge and they can't find the leak.

So I check it out. First I check the coils and notice a wiring mess behind the evap panel. So I clean it all up. I fire it up. It runs a 190 head, but suction drops down to 7psi. Then it slowly climbs and compressor shuts down on internal overload. I think it's a clogged cap tube. So I remove the gas on the low side and still have 150psi on the high.

So I conclude it's a clogged cap tube. Now my question is I plan on replacing the cap tube and drier. I searched on the forums about this and saw the supco link for sizing. But it lists low temp or med temp. What if it's both? Also do I really need to replace the oil, like I read on some of the posts.

Btw- It's a Enodis UC4148 refrigerator or freezer. And it has a Copeland AFE11C3E-1AA-301. The 301, I think means it's a non oem compressor?

Any help for a novice when it comes to small refer?

[Pascone10]

I am no expert on this subject but will relay what was explained to be about replacing the oil. Im my experience (very limited) the 2 systems I had run into with restricted cap tubes was caused from the condensors being blocked and the oil turning to wax. I tried blowing out the tube and was informed on some tricks after I was done working on the machine so i did not try them.

1. you can try and heat up the tube and free that wax build up.
2. cut off the first couple inches of the tube and braze it back in as this is where the restriction most likely occurs ( of course assuming this is what caused your problem..

So, replacing the oil, or compressor ( as it was recommended to me) is a not a bad idea to avoid future problems. Both times Quotes were given for the repairs the customer opted for a new unit..

Like is said ASCJ I asked these questions about 2 refrigerators I worked on and these were the agreed responses I was given. Just wanted to pass this info on to you. Good luck.

[ascj]

I am no expert on this subject but will relay what was explained to be about replacing the oil. Im my experience (very limited) the 2 systems I had run into with restricted cap tubes was caused from the condensors being blocked and the oil turning to wax. I tried blowing out the tube and was informed on some tricks after I was done working on the machine so i did not try them.

1. you can try and heat up the tube and free that wax build up.
2. cut off the first couple inches of the tube and braze it back in as this is where the restriction most likely occurs ( of course assuming this is what caused your problem..

So, replacing the oil, or compressor ( as it was recommended to me) is a not a bad idea to avoid future problems. Both times Quotes were given for the repairs the customer opted for a new unit..

Like is said ASCJ I asked these questions about 2 refrigerators I worked on and these were the agreed responses I was given. Just wanted to pass this info on to you. Good luck.

Thanks.

This a small hermetic compressor. What's the best way to change the oil?

I'm just not use to changing the oil without a oil port. Do you have to remove the compressor and try to dump it out through the suction service line?

[Pascone10]

Thanks.

This a small hermetic compressor. What's the best way to change the oil?

I'm just not use to changing the oil without a oil port. Do you have to remove the compressor and try to dump it out through the suction service line?

Yuppppppp.

[Paul Bee]

Are we talking 134a and poe oil ? Ascj so is it medium temp or is it a freezer? Describe the evaporator. Is there an evaporator fan? Is there a defrost heater?

[icemeister]

The Delfield (Enodis/Manitowoc) UC4148 is a 48" 2-door undercounter freezer and has a 1/3 HP R404A low temp compressor.

http://mtwfsuk.com/docs/uploaded/del...s/DSUC4000.pdf

It calls for a .036" x 168" cap tube.

http://mtwfsuk.com/docs/uploaded/del.../DM4_40_45.pdf

[pdrake65]

Thanks.

This a small hermetic compressor. What's the best way to change the oil?

I'm just not use to changing the oil without a oil port. Do you have to remove the compressor and try to dump it out through the suction service line?

Use an oil pump if you need change the oil.

[ascj]

According to the tag it can be a refrigerator or a freezer........but my friend wants it to be a freezer. It's 404a.

I know the cap tube is clogged and needs replacement. I just really wondering if the oil needs to be replaced.

[icemeister]

According to the tag it can be a refrigerator or a freezer........but my friend wants it to be a freezer. It's 404a.

I know the cap tube is clogged and needs replacement. I just really wondering if the oil needs to be replaced.

According to the manufacturer's spec sheet it's a freezer, not a dual temp unit.

If the capillary tube is plugged, yes you should always change the oil.

These little peanut compressors are so small the only good way to drain them is to cut them loose and invert them...dumping the oil either through the suction port or the low side service tube.

I like to cut the tubing rather than unsweat them. Drain the oil and measure how much you get. Then add the same amount of fresh POE.

To add oil to a 3/8" tube is easy if you make up a few reducing couplings to form a small funnel. Then pour your measured amount...slowly.

It's not that big a deal. It takes me no more than 30 minutes to change the oil in one of these little guys...and it's well worth it.

[crackertech]

Cape tubes.

[Paul Bee]

Icemeister aren't you going to tell him why he needs to change that oil? POE!! For everyone else's benefit you can NOT remove moisture from poe oil with a vacuum pump, only a good filter drier (and you might have to change it several times if you don't change that oil). And I would get a steel Alco drier not a copper spun one. You will get less pressure drop from an Alco than a Sporlan.

[icemeister]

Icemeister aren't you going to tell him why he needs to change that oil? POE!! For everyone else's benefit you can NOT remove moisture from poe oil with a vacuum pump, only a good filter drier (and you might have to change it several times if you don't change that oil). And I would get a steel Alco drier not a copper spun one. You will get less pressure drop from an Alco than a Sporlan.

The more direct cause of plugged cap tubes in HFC/POE systems is overheating...usually caused by a plugged up condenser or a failed condener fan motor.

One thing that plugs up cap tubes can be organic salts created from moisture in the system and subsequent overheating. Also, residual manufacturing lubricants that the POE oil has absorbed from the system will create deposit to clog a cap tube if overheated. The oil itself will break down if allowed to overheat sufficiently.

So the reason for changing the oil is because whatever the junk is that plugged that cap tube, it's still lurking about the system in the old oil.

When changing a cap tube fresh oil, a good filter-drier and proper evacuation are a must if you want to avoid call backs.

[Paul Bee]

Thank You Mr. Icemeister! I knew you could shed some light on the details. Thanks for the good info!!

[Airmechanical]

I am no expert on this subject but

1. you can try and heat up the tube and free that wax build up.
2. cut off the first couple inches of the tube and braze it back in as this is where the restriction most is

when i come across plugged cap tubes, most of the time i just replace the cap tube

but when i see and smell stinky brown oil, i use the three step plan

1.replace cap tube
2.replace compressor
3.install drier, evacuate,weigh in charge

never use a cappillary tube shorter than the original length

as for other statements on this thread about changing oil in a small compressor

a customers money would be better spent on a new compressor

as opposed to paying labor in order to change oil on an old compressor

may be a little more costly for the customer to install a new compressor

but it's a better plan for the customer, as well as the tech's callback percentage



.

[ascj]

Thanks for all the advise.

So it's a new cap tube, drier, and oil.

[jpsmith1cm]

when i come across plugged cap tubes, most of the time i just replace the cap tube

but when i see and smell stinky brown oil, i use the three step plan

1.replace cap tube
2.replace compressor
3.install drier, evacuate,weigh in charge

never use a cappillary tube shorter than the original length

as for other statements on this thread about changing oil in a small compressor

a customers money would be better spent on a new compressor

as opposed to paying labor in order to change oil on an old compressor

may be a little more costly for the customer to install a new compressor

but it's a better plan for the customer, as well as the tech's callback percentage



.

I would agree, but there are going to be a LOT of customers who will throw you out of their place of business for suggesting replacing a functioning pump.

As ice said, it only takes a short time to change the oil and is cheaper than a new pump, even if it might not be the best way to do it.

CYA. Give customer the option and do what they tell you to do. Document and you're covered.

[icemeister]

Thanks for all the advise.

So it's a new cap tube, drier, and oil.

I posted Delfield's recommended cap tube size yesterday as .036" x 168". That seemed a bit long to me so I did some checking.

Refrigeration Hardware Supply stocks that same for Delfield, so I assume it's not a misprint.

Then I look into what JB Industries and Supco call for with a 1/3 HP low temp R404A compressor. Both list it as .031" x 30". Using JB's cap tube conversion
chart to go from .031" to a .036" cap tube, they give a factor of 2...so 60" of .036".

This is a good example of how cap tube selection can be quite confusing.

[Some Dude]

Last time i had one of those it had plugged the cap tube because the evap leaked then it pumped into a vacuum .
Expensive messy fix, then again it was a beveragejunk unit.

[ascj]

.

[ascj]

The cap tube looks original. It feeds down to the evap. Then wraps around the suction line right after the coil 5 times. It then runs against the suction line to the back and into the drier. I can't imagine it's 168" long.

My guess would be around 50-70" long.