Carrier 19XRV - Oil Return Problem

[ChillerR123]

Hi All Carrier Experts,

I have just picked up 2 x 19XRV 1012 237BFS52S – apparently, they have history, but no one can tell me exactly what??

I am experiencing a problem on one of them with oil return ie: during an offline test, when the oil pump is run, the oil is not returning to the sump. In fact, each time we do an offline running oil pressure / pump test, the oil level continually drops (noted in the two sight glasses).

I carried out the exact same test on the chiller next to it (exact model) and the oil returns to the sump each time, and the sight glass levels are consistent.

When an operational test was done, the problem chiller also tripped out on “Check for Oil In OR Overcharge of Refrigerant” so a decent run wasn’t possible either. There is a history over the last 2 months of this fault.

We transferred the refrigerant from the bottom of the evaporator with the intent the oil will be here – alas, we filled up the oil tank again. Tested, and we are back to low levels again.

We have done other tests, but to keep it basic for now, this is what I have posted.

I am thinking there maybe a failed bearing / seal or something??

[JEF1980]

Has it been opened up recently if the oring behind the high speed seal is not installed you will have that problem oil loss while machine is not running everytime it runs the oil pump it will lose oil in off cycle.

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[ChillerR123]

Hi JEF1980, I was hoping for your reply

Mate I don't know if has - but looking at the paint on the bolts, it looks quiet original. My suspensions is that something has let go inside. If this is the case, would that give a direct path to the evaporator - like via the suction elbow?

[ChillerR123]

Scratch that... not the suction elbow.

[JEF1980]

It would be pumping the oil into the discharge volute if it was high speed laby or that oring if the low speed laby is damaged it would be pumping it into the stator housing which the drain goes to evap.

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[ChillerR123]

Ok. There is history of heaps of surges, and it had been running at super low load (from old logs i found). What would be a test procedure for confirming this? - PM if too much info for open forum

[pumpdown]

I am thinking about the oil problem here and I have a few questions to confirm what you are saying
1. when running the oil pump in test mode your oil pressure drops
2. your two oil sight glasses the oil level drops as well , and if thats the case what is the pressure it will drop to?
My first step would be to change the oil filter and if that doesnt fix the problem , I would remove the oil pump and get it rebuilt and replace the oil regulator. unfortunately not enough info to diagnose. What is the return cooling tower water temp? If too cold this could cause problems as well

[ChillerR123]

Hi Pumpdown, thanks for your reply. I didn't want to load up with too much info too soon. Oil pressure is about 200kPa delta T, so this is a little high, but certainly not low, so no indications of a massive oil loss. Throughout the tests, the oil pressure is constant too, it just doesn't return oil - hence the levels in the sigh glasses dropping during operation. We aren't even running, so the cooling tower temperatures don't come into play. There is a new oil filter installed too, so this has been ruled out.

[WYLBEK]

Time to open up and check seals.

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[ChillerR123]

WYLBEK, yep, I think so. From what i know, the insides of a 19XR is almost the same as a 19XL? You wouldn't have a tear down manual handy by chance? I'll check my folder of manuals too!!

[WYLBEK]

WYLBEK, yep, I think so. From what i know, the insides of a 19XR is almost the same as a 19XL? You wouldn't have a tear down manual handy by chance? I'll check my folder of manuals too!!

Check your mail.

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[carriermechanic]

If you run the oil pump while its off will it suck the oil level down and eventually not make oil pressure? also, I had to convert your oil pressure. I think you have 29PSI. If this is the case then thats great oil pressure. 29 psi is considered normal. If you can run the oil pump for 10 minutes and it maintains oil pressure then its getting oil return!! Ive seen a wiped out bearing scenario before. I turned on the oil pump and I could visually see the oil level go from the top of the top sightless and then down below the bottom sightless in a matter of 25-30 sec.

Its rarely ever a oil filter. Ive seen these chillers go several years and not have a filter change and not cause a issue. I can also say its rare to see bearing failure without seeing bad oil samples!! Unless someone has been in the chiller recently its not the orings.

When was the last time a oil sample was taken? See what the tin content came back as

Have you seen this chiller run? If yes, while its running does it return oil? Also can you send me a log or a screen shot of the ICVC while its running? Im curious what your approaches are (I'm asking this because the chiller shouldn't be surging)

Another thing to look at as far as surging is the software thats installed. If its a LF1 they are up to version 14. If its a LF2 its up to version 9.You want to make sure the surge prevention is tsmin/max. Also want to look at min VFD speed. make sure its not set at 70%

99% of the time when I see a chiller surging its usually flow, fouled tubes or low on charge.

[carriermechanic]

I normally tell customers to put condenser water set point to 65 degrees. Especially when they have a 19XR with a VFD. It takes care of a lot of issues.

You mentioned it runs unloaded a lot. This can be somewhat of a problem. You need to make sure it stays running and its not going into recycle shutdown due to no load. If the chiller is constantly starting and stopping it doesn't run long enough to bring the oil back. Also, when it runs unloaded its primary oil return is through the skimmer line on the side of the evaporator. If the refrigerant charge is not correct the skimmer line will not work properly. If the chiller is low on charge the level of refrigerant in the evap is too low. The oil rides on top of the refrigerant and the skimmer line pulls that oil off the top of level.

Ive actually seen a wide evap approach due to dirty evap tubes cause a "Check for Oil In OR Overcharge of Refrigerant" alarm

If you can get this chiller running check your discharge superheat. Discharge temp - condenser refrigerant temp.
If you have a lot of oil in the evaporator you will not have much discharge superheat. In fact it could be 0 degrees due to oil hitting the impeller. If you see this, limit your guide vanes to 0% and force your VFD to 100% until your discharge superheat is above 20 degrees. Once its above 20 degrees open your vanes a max of 2% at a time. You keep doing this until the discharge superheat stays above 20 degrees. at that point put everything back.

[ChillerR123]

Hi carriermechanic, I'll PM you.

[can]

Hi All Carrier Experts,

I have just picked up 2 x 19XRV 1012 237BFS52S – apparently, they have history, but no one can tell me exactly what??

I am experiencing a problem on one of them with oil return ie: during an offline test, when the oil pump is run, the oil is not returning to the sump. In fact, each time we do an offline running oil pressure / pump test, the oil level continually drops (noted in the two sight glasses).

I carried out the exact same test on the chiller next to it (exact model) and the oil returns to the sump each time, and the sight glass levels are consistent.

When an operational test was done, the problem chiller also tripped out on “Check for Oil In OR Overcharge of Refrigerant” so a decent run wasn’t possible either. There is a history over the last 2 months of this fault.

We transferred the refrigerant from the bottom of the evaporator with the intent the oil will be here – alas, we filled up the oil tank again. Tested, and we are back to low levels again.

We have done other tests, but to keep it basic for now, this is what I have posted.

I am thinking there maybe a failed bearing / seal or something??

The problem should be the o-ring (KK71EW015) between the impeller labyrinth and the gear box casing. Should lost or damaged.

[Loadrunner]

Hi, guys.
Need your help.
Sorry for bad English...

I have trouble with Carrier 19XR, 5 frame.
After overhaul (change all bearings, high speed shuft, labyrinth seal, impeller, and all o'rings and filters) chiller was loaded refrigerant and oil.
Around 100 hours it worked normally, but after this time oil level is rapidly droped. Chiller was stopped by alarm "Low oil pressure".
We added 5 gallons of oil, and loss it too. After this we have new alarm - "Low discharge superheat".
We try make oil return procedure, open vanes on 2%, oil and refrigerant in skimmer line glass present, flow is good, but oil level in low sight glass on compressor don't rise again.

What another reasons, expectly KK71EW015, we can have?

PS: If it need, i can add any another information.

[can]

Hi, guys.
Need your help.
Sorry for bad English...

I have trouble with Carrier 19XR, 5 frame.
After overhaul (change all bearings, high speed shuft, labyrinth seal, impeller, and all o'rings and filters) chiller was loaded refrigerant and oil.
Around 100 hours it worked normally, but after this time oil level is rapidly droped. Chiller was stopped by alarm "Low oil pressure".
We added 5 gallons of oil, and loss it too. After this we have new alarm - "Low discharge superheat".
We try make oil return procedure, open vanes on 2%, oil and refrigerant in skimmer line glass present, flow is good, but oil level in low sight glass on compressor don't rise again.

What another reasons, expectly KK71EW015, we can have?

PS: If it need, i can add any another information.

I know what happened, please wait me have spare time, I will let you know.

[Loadrunner]

OK, i'm waiting.

[can]

I know what happened, please wait me have spare time, I will let you know.

The oils was goto the cooler now and rise up the cooler refrigerant level. Only open the guide vane will return much refrigernats into to the oil tank and let the oil lost again. The oil lost after running 100hours, maybe the oil reeclaim filter(KH42ME060) and strainers (KH11NG070) was blocked. You should pumpout the refrigerants and replace these filters first. And than refill 70% of the refrigerants back into the chiller and restart it, and than trim the refrigerant level. Sorry by my bad English too!

[Loadrunner]

All filters have been replaced with new ones, and KH11NG070 was replaced again. And eductor was cleaning too.