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doggie
03-06-2009, 07:19 AM
Good day gentlemen...

I have 2unit 15HP Semi Hermetic Compressors and in order to increase cooling capacity I have to add one more 10HP Compressor... another thing is, I have to replace the existing condensers due to old age.

Now the question is... is it possible to use 3 compressors working together on a single "appropriate" condenser? Why?....

Thanks for your time....

subramanyam
03-06-2009, 08:57 AM
yes i think u can use single condensor, which should be designed to take the load of the three compressors, but when one of the compressors is put off, there is a un necessary energy waste,

doggie
03-06-2009, 12:21 PM
yes i think u can use single condensor, which should be designed to take the load of the three compressors, but when one of the compressors is put off, there is a un necessary energy waste,

Thanks for the reply... I expect the 3 compressors to be running full load most of the time so I don't expect to shut down any of the compressors

Is there any thing I should be aware of just in case I have to install my system this way?

D.D.KORANNE
03-06-2009, 12:43 PM
You can use three compressors in parallel , it should preferably have an equal volumetric displacement . Besides, a very effective oil return system is key to success , probably use oil reservoir & oil level regulator for each compressor . Moreover, head pressure regulation will be essential in the event that one or two compressors are cylced off . I can help in designing high side system for the application. PM ddk0123@gmail.com

lowcool
04-06-2009, 01:46 AM
dont forget balance line for sumps,one oil reservoir,one oil level control per compressor,check valves in discharge lines,correct suction header for oil return,maybe someone has a drawing out there somewhere,basically your making a rack.

lowcool
04-06-2009, 04:26 AM
dont forget balance line for sumps,one oil reservoir,one oil level control per compressor,check valves in discharge lines,correct suction header for oil return,maybe someone has a drawing out there somewhere,basically your making a rack.
go to your wholsalers engineer give him conditions of operation it would be more probable financially to run single comp than build up a hashed rack,2 old donks,one new donk,rehash add extras try and make it look trade quality.im sure bitzer would have a packaged job to suit.new pipework,new evap,less warranty problems more reliability.:)

joe magee
04-06-2009, 04:41 AM
You need to find someone that knows what there doing. The information you need is beyond the scope of this website. If it's not done properly you will have nothing but issues:D

lowcool
04-06-2009, 04:47 AM
You need to find someone that knows what there doing. The information you need is beyond the scope of this website. If it's not done properly you will have nothing but issues:D
psst dont let gary hear you say that:D:D:D:D

flavenido
07-06-2009, 08:56 AM
Adding compressor does not necesarrily mean, you can acheive additional cooling capacity. You must check the design of entire system to acheive desired result result.

Eeram
21-06-2009, 11:59 AM
Adding another compressor to the existing system, will need a re- assesment of the complete system, including piping design. That means suction header, discharge header, liquid line, suction line, condenser, receiver, oil management and controlling. You can add a different size compressor to the rack, as long as the smaller compressor is the lag compressor.

chemi-cool
21-06-2009, 02:34 PM
Adding a third compressor to existing unit is impossible!

The condenser is designed to reject heat from the existing compressors.

If you want to add more compressors, you will need to design a new condenser, new pipes, new TXV....

Actually, you will be building a new unit.

Peter_1
21-06-2009, 03:05 PM
dont forget balance line for sumps,one oil reservoir,one oil level control per compressor,check valves in discharge lines,correct suction header for oil return,maybe someone has a drawing out there somewhere,basically your making a rack.

I never install check valves in the discharge lines. This gives an additional DP and decreases system performance.
If you install floats on the sumps, then you don't need balance lines neither.

Peter_1
21-06-2009, 03:06 PM
yes i think u can use single condensor, which should be designed to take the load of the three compressors, but when one of the compressors is put off, there is a un necessary energy waste,

Why is their an unnecessary energy waste? I should think just the opposite :eek:

Peter_1
21-06-2009, 03:08 PM
You can use three compressors in parallel , it should preferably have an equal volumetric displacement . Moreover, head pressure regulation will be essential in the event that one or two compressors are cylced off . I can help in designing high side system for the application. ...[/EMAIL]
I have several packs running since decades with following compressors on it: 0.5 - 1 - 2 - 4 - 7.5 - 15 HP and eventually a 30 HP added to it or a second 15HP.

lowcool
22-06-2009, 05:13 AM
gday peter where i was coming from about balance line was maintaining the same sump pressure in all comps essentally where their is a large difference between compressor capacities,thats how we used to make em.

Peter_1
22-06-2009, 09:01 AM
You only need a balance line if all the sumps are linked together, if you work with floats then you don't need them.

Shingoshi
25-08-2009, 05:44 AM
Should there be a problem if you're building a new system with parallel compressors, and have chosen a condenser from the beginning to handle the load?

Seems that if this was designed from the start, you could eliminate problems before they could exist.

Shingoshi