Nasty Chiller.

Am i being unfair or is this a recipe for big problems?

Two chillers on a site in London. They are made by COSFI, with COMER V5 semi compressor's. Shell & Tube type, remote condensor. They were made in 2001, so far they have lost two compressors, and no one seems to know why. I was asked for a price to replace the compressor, having found out the above, i felt a little reluctent to get involved as it looks like a can of worms. having spoken to the Italian manufacturer, they no longer make the V5 model (343m3/h), the best they offer are 320 m3/h & 407m3/h. i have serious doubts whether either option will fit the chassis of the chiller or even perform to any extent. Anyone had any experience of these or have any suggestions?:D

.

Why buy an unknown pup?

Walk away.

.
________
digital scales

I cannot speak about the Italian compressors or chiller packages, but one thing I have done when faced with a similar issue is to use some other compressor manufacturer.

The refrigeration capacity is based on the compressor displacement. This does not change very much from compressor to compressor.

If you try to match another compressor based on the displacement to approximately the same as you have with the existing compressor (343m3/h) the actual capacity will be close.

I have done this in the past with old Dunham-Bush compressors (the big semi-hermetics). After a lot of problems and lost time finding replacement parts, I switched the compressors to Copeland (similar displacement).

If you use the Discus compressors you may be able to use a slightly smaller displacement compressor for the replacements. The Discus models will probably have a higer volumetric efficiency than the existing compressors did when new.

A few piping changes, some minor wiring differences and presto.... new compressors on the old package. Works like a charm.

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They were made in 2001, so far they have lost two compressors, and no one seems to know why

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Precisely the sort of job that can cause you to loose sleep. If you venture into this my recommendation is to make sure you have sufficient money in your bid to cover just about any contingency.

Something caused the compressors to quit. Could be electrical, liquid slugging, poor maintenance and dirty condensers, just about anything right?

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...as it looks like a can of worms

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For this precise reason it is in your benefit to have sufficient costs built into your bid.

There is nothing worse than getting a big job and find out it costs you money.:mad:

It might be worthwhile to look at one of the compressors to see if the problem is broken valves, motor burnout, etc. This could tell you what happened or at least point you in the right direction.

Hope this helps and good luck with it.

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Originally Posted by Daddy Cool

Am i being unfair or is this a recipe for big problems?

Two chillers on a site in London. They are made by COSFI, with COMER V5 semi compressor's. Shell & Tube type, remote condensor. They were made in 2001, so far they have lost two compressors, and no one seems to know why. I was asked for a price to replace the compressor, having found out the above, i felt a little reluctent to get involved as it looks like a can of worms. having spoken to the Italian manufacturer, they no longer make the V5 model (343m3/h), the best they offer are 320 m3/h & 407m3/h. i have serious doubts whether either option will fit the chassis of the chiller or even perform to any extent. Anyone had any experience of these or have any suggestions?:D

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in all honesty marc is the kiddie for this kind of thing.however due to a behind the scenes spat he is no longer here

cheers

richard

I would suggest a complete replacement of the chillers.
If the client doesn't like it, then walk away.

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Originally Posted by Jase

I would suggest a complete replacement of the chillers.

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I agree. This is the most safe thing to do. Argus had a similar recommendation.

My suggestion above is based on managing the risks involved. In this instance, the project was for an existing client who was reasonable to work with and paid quite well.

If the problem job is for someone unknown to you I would walk away also. Too many pitfalls for some unknown potential gains.:confused:

I know cosfi very well. They are just a few miles away from my place. V-series compressors were produced by Hanbell in Taiwan, and rebranded by COMER, a commercial company based in Florence, 100% owned by DORIN, also based in Florence.
V compressors are actually phased out, and the new series is called RC.
I can provide an offer for a drop in replacement, as I'm in contact with the italian importer, Mr Yen, who is in the board of directors in Hanbell China.
Please contact me by private message.

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Originally Posted by rbartlett

in all honesty marc is the kiddie for this kind of thing.however due to a behind the scenes spat he is no longer here

cheers

richard

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And he took a thread about Ze, R1, R2 and Zs values with him :confused: :confused: :confused:

cheers

eggs

hi sir
it is not logical to lost 2 chillers that fast
there must some problem in operation ,,
please check these items , it is common for burning compressors
1-supply voltage , and contactor contact points
2-refrigeration oil,must be 1/2 to 1/3 of the sight glass,and must be changed every 10000 hr. or 4 years
3-the cooling tower water charactristic , and the secondry refrigerant
4-the super heat dgree measured from expansion valve sensor ,

thanks and regards
afeef

I can only give an opinion on the electrical side of the system. I have been to a site where the compressors were being replaced every month! One of the reasons was that the liquid solenoid valve was energised when the compressors were stopped on their limit start timers. These timers were set for about 10 minutes. When the compressors started, a slug of liquid was sometimes drawn back into the compressor, smashing the valves. Changing the electrical control circuit to keep the liquid valve closed until the compressor was ready to start and altering the pipe work to fit a better slop pot, cured the problems.

Any idea of the reasons for losing the compressors? Hermetic (or semi-hermetic) motor burnout can be caused by refrgierant contaminants like moisture, acidity and solids. If you don't have any data on the refrigerant or oil, I think this is a good place to start when you are taking over a new system.

(There are of course lots of other reasons for comps failing)

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Originally Posted by Johnny Rod

Any idea of the reasons for losing the compressors? Hermetic (or semi-hermetic) motor burnout can be caused by refrgierant contaminants like moisture, acidity and solids. If you don't have any data on the refrigerant or oil, I think this is a good place to start when you are taking over a new system.

(There are of course lots of other reasons for comps failing)

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afeef: these chillers were condenserless, so remote condensers were installed, not cooling towers.
And Johnny, I would suspect this is the reason for the premature failure: dirty circuit by installer, or no oil return because of no oil traps or syphons.

If you can find reason of compressor failiure and replace the compressors the same will acour.Find the reason or give up.

Renato

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Originally Posted by Renato RR

If you can find reason of compressor failiure and replace the compressors the same will acour.Find the reason or give up.

Renato

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Correct. I quote entirely

Another reason for repeat failures is that everyone likes to constantly adjust TXV's and does not wait to see how the system stabilizes.

If the control circuit does not have phase protection or power monitoring this should also be added to the system. This is cheap insurance for those times when the power supply is a potential problem.

And of course, if the installation was done in a haphazard manner, all bets are off for good continued operation.

And then there is my favorite reason. The system is not cooling properly so we need to add refrigerant! :mad:

It's nice to know my gut instincts were right. Nothing was adding up. I made it very clear to the client that compressors don't fail that quickly and frequently without something being wrong. I was quiet blunt at one point and said i don't think it's morally or commercially right to just take his money and blindly replace the compressor leaving my phone number on the machine so they can call me again in six months. i think i will offer to quote for new machines, and condensers including pipework etc or nothing at all. It's just not worth the headache of it all.

I need the beauty sleep, and can't afford sleepless nights.

Thanks for everyones opinion.:D

Non return valve on the HP line?

Maybe liquid is running back to the compressor when it stops?

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Originally Posted by rbartlett

in all honesty marc is the kiddie for this kind of thing.however due to a behind the scenes spat he is no longer here

cheers

richard

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LOL. i was just starting to really respect his opinions as well.

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Originally Posted by Daddy Cool

I was quiet blunt at one point and said i don't think it's morally or commercially right to just take his money and blindly replace the compressor leaving my phone number on the machine so they can call me again in six months.

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I think this was the proper course of action. First off it shows integrity and complete honesty. Second, this shows you are trying to work with the clients best interest in mind.

If you don't get the job after this, you probably don't want to get it anyway.

There are some jobs that are better for someone else to be awarded, if you know what I mean?:D

As for the topic at hand, cheap Italian chillers are ten a penny these days. frequent pot failures can be caused by many things. the possible way to go would be to source alternative compressors. if it were me then acid tests and as much investigation beforehand as possible to attempt a realistic diagnosis would be a starting point.

it does sound like these are very cheap/poor in the first place or there is a miscalc in something that was sized originally.

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Originally Posted by slingblade

As for the topic at hand, cheap Italian chillers are ten a penny these days.

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In fact it was a chinese compressor to fail, in a condenserless chiller installed by an english contractor.

I've done few job like this, I just use the existing evaporator, condenser, piping, pumps and starter panel, and I install J&E Hall open drive compressor. I also use J&E Hall Fridgewatch controller which take care for everything(start/stop, monitoring, safety limits, capacity control). Most of the compressor I replaced are Trane semihermetic & dunhambush semihermetic. Never had a problem with J&E Hall open drive.

Guapo.

Who designed it? Where are the installation drawings? 2001 wasnt that long ago. Speak to the organisation that concieved the chiller and get the commissioning details from when it was installed, compare the sets of details and you can establish that it was and has ben working within design perameters, It is quite likely that the origunal instalation wasnt commissioned properly and the failures are a result of someone trying to treat the effect rather than the fault, unfortunately you wont be able to bottom this until you get it running again and then the design perameters may not have been met. if you cannot get hold of this information my advice is walk away.
I would.

Clivet,

Commissioning details and O&M's drive me insane.:mad:

i think i have mentioned before that i have seen O&M's on a large site, installed by a very large contractor that went as follows:

'Additional refrigerant charge added'......'YES' is that latin for 36.72Kg's? i don't know either.:mad:

I spend hours doing the bloody things, just finished a vast file with the inside leg measurements of the bloke down the road.(well almost)

There are no logs or O&M's to be found on site, and although i have a good idea who installed it (i will say no more on a public forum about that one) they won't talk to me.

Part of me says walk away, but i feel the building owner has been sold something on cost alone (regardless of who made the chiller) and i feel it gives the whole industry a bad name. In trying to convey this message, i get the feeling we are being tarred with the same brush, and are just looking for a quick buck by rubbing my chin, shaking my head, and taking a sharp intake of breath, while saying ' i don't know which cowboy put this in mate' i want the chance to right the wrong, and show them that a good design and selection will pay in the long term. Enough ranting, i'm going to have a heart attack, and i need to finish the O&M's.

If you really want to help the guy out then I think you already know it is unlikely to be cheap or easy for him, so fill him in and let him know. If he decides to go with someone else because they're cheaper even if they're going to just keep shoving new comps in until they stop breaking, unfortunately that would be his choice. Customers can be a difficult lot, there often seem to be ten who think they know best for each one that has figured out they are paying you to know what you're doing.

where is my reply?

Hi Guapo:)

JE Hall compressors are a bit lost on the guys over here:D

For all thatJE Hall is an english company most over here won't have seen JE Hall compressors, they will be thinking of large industrial compressors:eek:

If you look at the www.jehall.co.uk

they sell a smaller open compressor, blue colour, this is a Bock re-badged.

JE Hall no longer manufacture piston compressors. If you are using Je Hall piston compressors it is either Bitzer rebadged (APV ) or bocks or somebody copying Halls compressors.:)

And as for Fridge Watch, this would be considered an industrial controller, it is good, but a little out of date. Comercial chillers use either Carel, Eliwell or Dixel controllers. I use Danfoss on retrofits, mostly a pack controller controlling on pressure and an evaporator controller with an electronic valve controling the chilled water, networked with the optomiser set up or just usually a simple pumpdown circuit.:)

I would have no fear of working on any plant, matter how badly installed, if you know the basics, you can fault find:)

Log the Superheat suction and discharge

Subcooling off condenser and at the valve

Evaporation and Condensing

Throw in the compressor amperes and the compressor manufactures data and this will get you started.

May be just poor compressor starter contactors killing you compressor, or an over sized chilled short cycling.
This you can check with spec on the plant, or just use the old eyes:D Compressors cycling off on you will see. Flashed contactors you can also see.

A simple chiller like this can prove a good learning process, if you fix it you will be the better for it:)

Me if I had the time I would sort it, but only after letting the owner have an up front report, the most you can loose then is a days labour on site and the time spent writing the report;) If the customer does not agree at this point it is their loss, I would walk away and bill him for the report.

Kind Regards. Andy:)

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Originally Posted by Daddy Cool

Am i being unfair or is this a recipe for big problems?

Two chillers on a site in London. They are made by COSFI, with COMER V5 semi compressor's. Shell & Tube type, remote condensor. They were made in 2001, so far they have lost two compressors, and no one seems to know why. I was asked for a price to replace the compressor, having found out the above, i felt a little reluctent to get involved as it looks like a can of worms. having spoken to the Italian manufacturer, they no longer make the V5 model (343m3/h), the best they offer are 320 m3/h & 407m3/h. i have serious doubts whether either option will fit the chassis of the chiller or even perform to any extent. Anyone had any experience of these or have any suggestions?:D

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Hi mate. Just wondering if you had a chance to do a heat load estimate for your application and seen if the old chiller still is the right capasity for the job??

You say that you have lost 2 compressor,with what have you replaced them with. No matter what comopressor is being used there must be a reason for its failure.

I HAVE ALSO FOUND THAT WHILE WORKING ON A CHILLER SITE WITH A FlooDED COIL SYSTEM I HAVE HEARD COMPRESSORS START WITH SING THAT CAN ONLY BE LIQUID GOING THROUGH Hp VALVES . A CHECK VALVE on the head preasure side IS A MUST. Compressors do not just pack up even if they are are Italian.

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Originally Posted by RODNEY

Compressors do not just pack up even if they are are Italian.

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Those compressors were chinese, not italian. No need to be funny.

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Originally Posted by dogma

Hi mate. Just wondering if you had a chance to do a heat load estimate for your application and seen if the old chiller still is the right capasity for the job??

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Hi Dogma,

No not yet, i do need to get back to this site, and find out what's happening.

I will keep you posted.

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Originally Posted by RODNEY

You say that you have lost 2 compressor,with what have you replaced them with. No matter what comopressor is being used there must be a reason for its failure.

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The compressors were changed by 'others' i don't know who, we were asked to take a look at a straight forward new compressor, i expected to find something out of the arc, but after some questions found they had already lost two compressors, and the units are fairly new.

General request to all.

i'm sure many will tell me it's not my place to say, but we need to keep to the subject, and not what nationality made the components or who installed them:o

i respect the opinions of you all where ever you may be, but i don't want to get into which counrty is the best/worst:D

:cool: AUSTRALIA:cool: is by far the best country Daddy Cool. Sorry, but it's the truth and just has to be said.:rolleyes: :D

On a more serious side....... Is your oil return OK? and what safetys do you have on your compressor? Are they set right and been checked?

Ahhh Dogma, Australia, like so many other countries is full of our cast off's:D I'm only joking, i have never been, but from what i have seen it looks great. My last proposal was to remove the compressor and sent back to re-man's for an independent report. That way, i can't be accused of running down anyone that may (or may not) have been doing the maintenance for them.:eek:

I think they want the magic fix, give it a kick, charge the price of a cup of coffee and it will run until the end of time. How jaded i have become, good job i'm on holiday for two weeks from thursday night!

hi if some have tritherm AJ 2120i/HA3R chiller eletrical control diagram please send it to my e-mail airaakram@yahoo.com

Nasty chiller or just some engineering problems to sort out ?

Hanbell own Comer, not Dorin. We use Hanbell as retrofit compressor of choice. The early V series have been drastically improved, but Carel controllers commonly used on Cosfi and other Italian chillers are very rough on the slide valve.

We would take this on and guarantee the results !


Please contact me by PM is this is still in your sights as a job.