Oil problems with a dual temperature pack.

[Chunk]

Hi all,i`m having some real problems and i am stuck with where to go next.

I have a dual temp pack with 3 Lt compressors and 3 Ht compressors(same pack from my other posts with moisture problems).The problem i have is that when the 3 Lt compressors run,they take all the oil from the Ht`s.
They all run off of 1 oil feed and i have fitted a differential valve in between both sets but still have the same problems.

I have replaced all 6 oil regulators in the past week,due to either over feeding or blockages,replaced head gaskets in 2 of the Lt compressors and replaced the internals on the capacity regulating heads due to various faults,so these compressors are all now in good working order.

I am in need of some suggestions on how i can get a balanced oil feed to both sets of compressors because i cant think of anything.

P.S

I have a twin of this pack and the same problems apply to this also,but not as bad.

Any help would be appreciated.

[Grizzly]

Chunk.
Perhaps a float level controlled oil switch/ reservoir on each of the comps.
That way the LP side would still take preference but once the level was satisfied.
At least the hp side would then receive some oil.

Steve

[Chunk]

Hi Steve.

We were toying with the idea of fitting Traxoil units to the comps,but even though i have cleaned the system to the best of my abilities,there is too much sh1t still in there and will definately cause problems.I am not allowed to get a Temprite oil sep,which is a shame.

One silly question,on a dual temp pack with all the compressors on the same level,which compressors should be fed first,LT or HT?

[Grizzly]

Hi Steve.

We were toying with the idea of fitting Traxoil units to the comps,but even though i have cleaned the system to the best of my abilities,there is too much sh1t still in there and will definately cause problems.I am not allowed to get a Temprite oil sep,which is a shame.

One silly question,on a dual temp pack with all the compressors on the same level,which compressors should be fed first,LT or HT?

Logically it would not make any differance as the lp systems would always take presidence.
I say logically because no doubt someone may well be able to prove otherwise.

Below is from the Henry Web site.

What oil regulator should I use for my compressor?
		Most people use an adjustable mechanical oil regulator such as the S-9130 or S-9090 for reciprocating compressors. These regulators are rated for 90 psi differential pressure (oil pressure minus crankcase pressure) and are adjustable between 1/4 and 5/8 sight glass. Fixed level regulators are available, but must be chosen according to the compressor manufacture's suggestions for oil level. Since these regulators cannot be adjusted they are rated for 30 psid instead of 90. For scroll or hermetic compressors, electronic oil regulators such as the S-9030 are typically used that include an oil level alarm to signal when oil level in the compressor has been lost. As adapter kit is required for any compressor without a standard 3 bolt 1 7/8" B.C. sight glass pattern.
follow this link for some more details.
http://henrytech.turnpages.com/usa/		Steve. click on compressor protection.

[Grizzly]

Chunk
In the above link to Henry check out pages 69 70 and particularly 71.
Anyone else with some idea's I presume there are many out there with more pack experience.
Steve

[Chunk]

Great booklet Steve.

This is where my problems lie.

The original regulators are now obsolete and being Bitzer compressors they have 4 bolt holes on comps.ESK and Henry dont make 4 bolt regulators any more and suggest you use S9090 regulators with Bitzer adaptors.I dont have space between the compressors to fit regulators and adaptors.

So along came ESK with 5 hole regulators that are bascically 3 hole regulators that have been drilled out and will fit 3 hole compressors and 4 hole compressors and these are the only ones we can fit(i dont think they are fit for purpose though).

Few more phone calls in the morning

[chillin out]

Do the comps have their own suction filter?
If so remove them and retest.
Also check the gauze filter inside the suction stop valve.

I sounds like the LT side is trying to drag gas through the equalization pipes for the oil from the HT comps.
Thus sucking oil and dropping the level in the HT comps.

Chillin

[Grizzly]

Great booklet Steve.

This is where my problems lie.

The original regulators are now obsolete and being Bitzer compressors they have 4 bolt holes on comps.ESK and Henry dont make 4 bolt regulators any more and suggest you use S9090 regulators with Bitzer adaptors.I dont have space between the compressors to fit regulators and adaptors.

So along came ESK with 5 hole regulators that are bascically 3 hole regulators that have been drilled out and will fit 3 hole compressors and 4 hole compressors and these are the only ones we can fit(i dont think they are fit for purpose though).

Few more phone calls in the morning

Good luck.
Let us all know how you get on!
As I don't expect you are the only one who will experience this problem.
Steve.

[BESC5240]

Hi Chunk,

As I understand it, the HT compressors do not get (enough oil). Could it be the pressure in the oil receiver is too low. What differential pressure valve do you use (20psi)? Is this valve connected to the suction of the LT or HT?
It should be connected to the suction of the HT, and you should use Oil Level controls that can withstand 90 psi (at least on the LT compressors).

[Chunk]

Hi Guys

Right,

No suction filters in compressors,removed a couple of weeks ago after system cleanup.Each system has it`s own scavenger lines so LT and HT are seperate,they only share discharge and oil feed pipework.

Oil pressure in receiver is 70 psi with 20 psi diff valve,taken from HT side and all compressors have a 30 psi ish oil pressure.The oil regulators are adjustable and can be adjusted between 5-90psi.Plenty of oil in system,all filters and strainers replaced or cleaned,transducers reading ok and comps appear to be working properly.

When LT comps are valved off,the HT comps are satisfied with oil and show 1/2 sightglass in regulator.If any of the 3 LT comps have their oil shut off valve even slightly open,the oil is reduced in the HT`s to a point where they trip on oil failure after an hour or so.All 3 LT comps when running will foam permanantly in their regulators as if they are not satisfied,but this is what gets me,when oil line is shut to an LT compressor when it is foaming,the regulator shows the comp is full and when opened again,the oil just empties and is foam again.

I have fitted a reciever diff valve(20 psi) in the oil line between the HT and LT comps to try and slow down the rate of oil getting through and because i am going on holiday for a couple of days,someone else is going back to check on it tomorrow.

I am hoping a fresh set of eyes will find something i have missed,because the original fault started as no oil to LT comps and after i have been pi55ing around with it for a week or so,i am losing the HT`s.

God i do love oil problems,even more than tiny gas leaks and rats stuck in condensate drains.

[chillin out]

It still sounds like you are pressurizing the HT comp's body and forcing the oil out the regulator.

Can you hear the relief valve on the oil receiver dropping gas into the suction when the LT system runs?

You might want to isolate each comp in turn to find the fault.
Also, take a pressure reading of the HT comp body before starting LT and during.

Oil problems usually lay far away from where you think the fault may be.
(i.e. Comp 4 giving problems could be because of a fault with comp 1)

Chillin

[Chunk]

It still sounds like you are pressurizing the HT comp's body and forcing the oil out the regulator.

Can you hear the relief valve on the oil receiver dropping gas into the suction when the LT system runs?

You might want to isolate each comp in turn to find the fault.
Also, take a pressure reading of the HT comp body before starting LT and during.

Oil problems usually lay far away from where you think the fault may be.
(i.e. Comp 4 giving problems could be because of a fault with comp 1)

Chillin

I have tested each compressor and have replaced any parts that have affected the proper running of each.None of the compressors have high sump pressures and hold their own oil for a couple of hours.

I couldnt hear any hissing from the oil receiver,but to be on the safe side they are replacing the diff valve today and my supervisor is going in to try something else.

If they find anything over the next couple of days i will post the findings,otherwise they might just leave it for when i get back.

[tony--1]

Hi

Does the pipe work after the oil receiver relief vavle go into the lt or ht suction ? just i had a artic circle pack where they hed fitted it into the lt suction and it drain the ht comps of oil.because of lower lt suction pressure.foaming oil in lt maybe liquid floading back ?

[750 Valve]

sheeesh chunk, you have one hell of a stubborn rack there, its been giving you grief for a while now mate. Wish I could be of any help mate but it sounds like all the usual things have been checked. If you do end up wanting to fit traxoils just throw a Sporlan ROF oil filter in the circuit - they really work well, with traxoils we don't use anything else.

[taz24]

I will add two points that I can think of at the moment.

Some duel temp packs I have worked on have two pressure reducers in the oil, 1 for the HT and 1 fot the LT both set accordingly. Also a daft question and I know your systems won't have this fitted but I am going to ask any way. Is the oil level in the comps ballenced out by the ballence line and it they are the HT arn't connected to the LT are they??
They can be on some packs but have a valve between the two.

Just a thought .

taz.

[coolhibby1875]

i had the same problem on a duel temp pack in a sainsburys 3 comps on top 3 on the bottom like you said a lot of foaming in the oil sight glass i fitted a temprite problem gone

[fowlie]

just a quick question but when fitting oil reg/floats to bitzers they must have a half moon shape adaptor fitted onto the float/comp or you will get problems the esk regs need an seperate adaptor but i think henry ones are prefitted

[BUSHY]

the low temp rack is more than likely taking the oil because it runs at a lower suction pressure causing oil to take least path of resistance it really should have a seperate oil sep and float for two different racks running at different pressures also i would be checking why low temp rack is losing so much oil out of the compressors

[Chunk]

Hi all,Thanks for the replies.

Over the past 4 days a couple of other people got involved because i went away.I came back today with it sort of running,a couple of compressors switched off and a load of parts on order.

The diagnosis i was given,was,that 2 of the 6 regulators i fitted(brand new)were faulty causing 2 of the LT comps to get too much oil and then draining the HT`s.

Also one of the LT comps that i had repaired was pumping too much oil,so that is now going to be replaced.

The regulators i fitted were ESK and do not have the halfmoon bits on them.These are the only ones they have that fit,and after another phone call to Henry,they couldnt help me out either.

The old regulators had balance lines just on the LT comps,but these new regulators do not have the connections to refit them.

We are going to throw more money at it this week and i have written a letter to Father Christmas asking for Traxoil,and i dont mind having to sit on his lap to get it.

[750 Valve]

We are going to throw more money at it this week and i have written a letter to Father Christmas asking for Traxoil,and i dont mind having to sit on his lap to get it.

watch that sly old father christmas, he may give you more than a traxoil if you sit on his lap...

[Porkington]

the low temp rack is more than likely taking the oil because it runs at a lower suction pressure causing oil to take least path of resistance it really should have a seperate oil sep and float for two different racks running at different pressures

I'll have to mention that idea to Radford.......

[Chunk]

I'll have to mention that idea to Radford.......

The funny thing is that this Pack was made by Radfords in 1996 it sat in storage somewhere until 1999 when it was then modified to be installed in my Sainsburys store.

It was never intended to be used for what it does now and over the past 8 years has had to be modified as we go along.And still after 8 years we cannot get it to go for long periods of time without causing some sort of problem.

But...

i fitted a new compressor yesterday and replaced 2 regulators,and for the 1st time EVER i now have all 6 compressors running,they have oil levels in the regulators(which is also a 1st)and some builders have put some ventilation in the plant room.

I will give it a week before something else gives up because its all too good to be true.

[Porkington]

Yeah Chunk, my tongue in cheek comment was pointed at BUSHY. Radford and multiple other manufacturers seem to manage with only 1 Oil Sep on HT/LT packs.... i'm not quite sure where he was coming from.

As for your particular problem.... i have a Radford HT/LT Pack in one of my Sainsburys stores. 3 LT on top... 3 HT on bottom... im sure you know the style. We've had intermitant problems with Comps tripping on oil but nothing as you describe.... i only just took over the store recently but the tell tale marks of a hammer on the Oil Sep and Reg's tell me the problem has been a common one.... i actually took time to drop the Sep and sorted the problem in 45 minutes... Lazy ****ers!!!!!

As for your problem, i had similar problems with an old 5 Comp Bitzer pack a few years ago.... we got the Comps running back up to full duty after Comp failures and the problem was solved.

Hope it runs for you and can you let me know what store it is so i can avoid it when im on call!!!

[Chunk]

Yeah Chunk, my tongue in cheek comment was pointed at BUSHY. Radford and multiple other manufacturers seem to manage with only 1 Oil Sep on HT/LT packs.... i'm not quite sure where he was coming from.

As for your particular problem.... i have a Radford HT/LT Pack in one of my Sainsburys stores. 3 LT on top... 3 HT on bottom... im sure you know the style. We've had intermitant problems with Comps tripping on oil but nothing as you describe.... i only just took over the store recently but the tell tale marks of a hammer on the Oil Sep and Reg's tell me the problem has been a common one.... i actually took time to drop the Sep and sorted the problem in 45 minutes... Lazy ****ers!!!!!

As for your problem, i had similar problems with an old 5 Comp Bitzer pack a few years ago.... we got the Comps running back up to full duty after Comp failures and the problem was solved.

Hope it runs for you and can you let me know what store it is so i can avoid it when im on call!!!

Yeah i dont mind the 3up/3down packs,this ones an all in one line job and i wish it was just cleaning the sep but heyho.

Its Sainsburys in the lovely city of Canterbury and looks like a big ugly metal hedgehog.Keep well away.

[750 Valve]

Porkington - I think BUSHY was only suggesting what he sees, I don't think he meant anything by it. Over here the major chains don't go for split suction group racks too often, they prefer 1 x LT, 1 x MT and 1 x HT completely separate racks, with their own sep, receivers, controllers and swbd's so he probably doesn't know of too many split suction group racks. We mainly see them on LT only, a -30 suction group and a -35 suction group for wide islands... but we use traxoils on nearly everything now and have done for a number of years now.

[BUSHY]

Yeah Chunk, my tongue in cheek comment was pointed at BUSHY. Radford and multiple other manufacturers seem to manage with only 1 Oil Sep on HT/LT packs.... i'm not quite sure where he was coming from.

As for your particular problem.... i have a Radford HT/LT Pack in one of my Sainsburys stores. 3 LT on top... 3 HT on bottom... im sure you know the style. We've had intermitant problems with Comps tripping on oil but nothing as you describe.... i only just took over the store recently but the tell tale marks of a hammer on the Oil Sep and Reg's tell me the problem has been a common one.... i actually took time to drop the Sep and sorted the problem in 45 minutes... Lazy ****ers!!!!!

As for your problem, i had similar problems with an old 5 Comp Bitzer pack a few years ago.... we got the Comps running back up to full duty after Comp failures and the problem was solved.

Hope it runs for you and can you let me know what store it is so i can avoid it when im on call!!!

porkington no need to be to defensive just calling as i see it, did you have a bad day or did your boyfriend steal your handbag or your lacy pink g string this is a forum where everyone can have a opinion not just you as 750 valve suggested we dont see too much of that kind of setup here.it probably is not good practice to be set up like that anyway.

[Porkington]

Like i said... my comment was tongue in cheek.

I just find it ammusing someone suggesting that multiple manufacturers somehow have got it wrong.

Theres nothing wrong with the 3 up 3 down pack sharing a common Oil Sep. They've worked for years.

As for the Thong comment..... why, you want to borrow it?

[BUSHY]

Like i said... my comment was tongue in cheek.

I just find it ammusing someone suggesting that multiple manufacturers somehow have got it wrong.

Theres nothing wrong with the 3 up 3 down pack sharing a common Oil Sep. They've worked for years.

As for the Thong comment..... why, you want to borrow it?

they dont sound like there running too well at the moment,dont let the clouds get in the way everything is done at a price

[750 Valve]

there are a few kicking around over here but not too many as the majors won't trust their whole store to one electronic rack/defrost controller (CPC, Danfoss AKC55, etc) but they do work alright and surely do cut down the cost of the installation, its just a bit more tedious to find that oil fault when it happens (as demostrated by this thread). Thankfully as mentioned before we are big on traxoils over here which cuts down on probs like these.

[Chunk]

there are a few kicking around over here but not too many as the majors won't trust their whole store to one electronic rack/defrost controller (CPC, Danfoss AKC55, etc) but they do work alright and surely do cut down the cost of the installation, its just a bit more tedious to find that oil fault when it happens (as demostrated by this thread). Thankfully as mentioned before we are big on traxoils over here which cuts down on probs like these.

All our new stuff comes with traxoil fitted which is nice.

We have been fitting some of the old kit with traxoil and it dont work,not nice,but we are learning.

[Chunk]

I`ve got to laugh

Today all the problems started again,traced fault back to the compressor i changed a couple of days ago.

As of an hour ago,this LT pack no longer has 3 compressors,it is going to run with 2 until i die or the store gets a refit.

[750 Valve]

All our new stuff comes with traxoil fitted which is nice.

We have been fitting some of the old kit with traxoil and it dont work,not nice,but we are learning.

On the older low pressure oil systems you have to do a few mods to the traxoils to work, now I haven't done one in a while (all our oil circuits are under hi side pressuer these days) and am a bit unsure whether you can still do this or require a totally different traxoil.

There used to be a restrictor just behint the strainer assembly that was removable, the hole in the restrictor plate was very small to allow a slower flow of oil when the traxoil energised and dumped hi pressure oil into the sump. On a low pressure oil circuit (ones with hi side floats delivering oil to a separate reservoir - reservoir has 20 pound check valve fitted to bleed excess pressure into header - like the one you describe on this rack) you need to remove the restrictor in the traxoil so that when it opens up it can flow an adequate amount of oil into the crankcasse from the relatively low pressure oil circuit.

Oh, and you MUST fit a good filter in a traxoil system, as I mentioned the Sporlan ROF filters are perfect for the job



But I see this one has been fixed.... if in doubt cut it out

[CHilly1]

FIrst where is the oil going to? Does the system have an oil seperator? Does the system have a full rez of oil? Does the system have a capacity control for the condenser? Fan control or flow control? Do you lose oil when only one low temp compressor runs? what happens when you lock out one low temp compressor and run the system with everything else calling? Does the system have an oil cooler? Water cooled or refrigerated?

I am assuming the high temp system is tripping on loss of lube I would first look for a malfunction in the oil seperaotor or if it has an oil cooler I would look at the feed rate or capacity of that.

[Goober]

I read an article from copeland bout this very thing and how some comp's seem to get oil and others don't. The article in a nutshell blamed the wear in the old comp's, if the comp's are old. The more wear, however small, required more oil to be required to lubricate the extra surface area and clearences resulting from wear. And that this was a common problem in daul/single temp racks. Sorry can't direct you to a on line copy, but it was one of copelands regular technical releases backed up with heaps of test data. It opened my eyes.