Frigosystem chiller

Hi all! Although been registered for sometime never actually post much :o

Now i have a Frigosystem chiller that need to repair.
The model is a RACA 200 and it had a semi copeland model D4SA1 2000 in it burned out.
Burned out due to one of the suction valves completely dissapeared :confused:.

Costumer says that every 2-3 years the compressor burns out and needs to swap it, therefore hes not very happy... Already had to swap compressor 3 times :eek:

Im thinking of swapping for a bristol or bitzer compressor.

Has any of you guys ever came across this compressor problems on this type of chillers?

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Originally Posted by Blaster

Costumer says that every 2-3 years the compressor burns out and needs to swap it, therefore hes not very happy... Already had to swap compressor 3 times :eek:

Im thinking of swapping for a bristol or bitzer compressor.

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This does not sound like a compressor problem, but more of a system design/operation/maintenance problem.

Something else is wrong with the system besides the compressor if it has to be changed every two or three years.

When a semihermetic burn, I know there's the need to "wash" the system from acid generated by electrical burning of compr motor. Discard oil, refrigerant, any type of filter in the circuit. There's specific products to make this. Sometime, in big chillers, you need to add specific acid remover cartridges in suction line, and some acid moisture traps in liquid line. It's not simple, and it cost a lot in therms of work and materials. Copper components such pipes and motors windings are highly affected from burnout consequences.
Hoping to be clear, regards and good work !

:)

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Originally Posted by US Iceman

This does not sound like a compressor problem, but more of a system design/operation/maintenance problem.

Something else is wrong with the system besides the compressor if it has to be changed every two or three years.

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Hi:)

there is a known issue with discus compressors breaking the suction plates, one of the few cases where I would say it is probably a genuine compressor fault.

But just incase I would check the suction superheats.

The compressor is NOT burnt out, the windings have not failed, it's just mechanical drama;)

Kind Regards Andy

Hi Andy,

Quote:

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Originally Posted by Andy

there is a known issue with discus compressors breaking the suction plates, one of the few cases where I would say it is probably a genuine compressor fault.

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OK, I'll ask the question that begs to be asked here. What problems?

I will be the first to admit it has been a long time since I have worked on these, but on every one I had experience with, I never (repeat never:D ) had any problems with Discus compressors.

I had heard there were some problems with valves, but I was under the impression is was due to operation outside of the application envelope.

When I hear stories of repeated equipment failures, I normally think of system related problems. Especially, if the equipment lasts for two or three years.

The part of the original post I have trouble understanding is the broken valves and "burned up compressor". That seems to suggest two problems, not one.:confused:

Broken valves are generally due to the compressor trying to compress liquid, have found this to be oil in the past, systems with oil seperators fitted but no non return valve down stream of oil sep, during off cycle the refrigerant can condense in the oil sep, the float lifts and dumps it in the sump, on start up the oil foams and the pistons pump oil, hence broken valves. A solenoid valve in the oil return line is no good as a full oil sep then still dumps liquid at 1/4" bore into the sump, not good!

Quote:

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Originally Posted by US Iceman

Hi Andy,



OK, I'll ask the question that begs to be asked here. What problems?

I will be the first to admit it has been a long time since I have worked on these, but on every one I had experience with, I never (repeat never:D ) had any problems with Discus compressors.

I had heard there were some problems with valves, but I was under the impression is was due to operation outside of the application envelope.

When I hear stories of repeated equipment failures, I normally think of system related problems. Especially, if the equipment lasts for two or three years.

The part of the original post I have trouble understanding is the broken valves and "burned up compressor". That seems to suggest two problems, not one.:confused:

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Hi Iceman:)

I have seen problems with Discus compressors on Ester oil R404a and low temperature systems, and what I would call over sized condensing units.

I would say it could well be down to over sizing of condensing units. It is common for the duty to be sized for a 16 hr run time, so 10kw evaporator will have a 15 kw condensing unit fitted, causing the suction pressure to run below the normal operting envelope. These units will also be designed for a 34 deg c ambient which they will actually only run at a couple of days in a year max. Again dragging the suction pressure down.

Yep it is all down to sizing:eek:

Kind Regards Andy:)

Thnx for the replys guys :)

Sorry Andy but i dont know what is a discus compressor :(

This is a frigosystem chiller used in cooling water from plastic injection plant, so its a HBP system.

Client has another chiller with exact same specs (frigosystem raca 200) that has a bristol compressor and that never had problems :confused:

Unfortunally bristol has a poor commercial distribution here in my country, but will probably go for it, if i can have a quote.