water-cooled chiller

[fir]

Hi all :p Im a newbie to chiller,condenser and cooling tower which im currently working in (a building). I hope u peeps could help me out with a couple of qns
1: I have a multistack chiller that have 6 compressors.how are the cooling tower and condenser and chillers related?
2 : There are 3 compressors in the chiller that lately seems to have problems. the compressors will trip almost everytime we reset it. What im being told is to press the HP button in the modular and then press reset on the touch-screen sensor. But yet it still trip. :confused: The discharge pressure will rise up to 1500kpa and then trip. Then It stated "FAULT --- HP" What should I check?
Just FYI, before I join the building, I notice there are 2 cooilng towers with 8 cooling tower fan motors in the rooftop, 3 condenser pumps and 3 chill water pumps. Now theres only 3 cooling tower fan motors and 2 chill water pumps that is running.
:p ask me if you need me to include anything.cheers!

[alphi]

Hi,

Question no. 1: I have a multistack chiller that have 6 compressors.how are the cooling tower and condenser and chillers related?

Cooling tower cools down high pressure gas in the condenser into high pressure condensate. High Condensate in introduced to your chiller evaporator via expansion valve to Low pressure that expands to your evaporator wherein you hot media (water) cool down to the designed duty.

Question no. 2 : There are 3 compressors in the chiller that lately seems to have problems. the compressors will trip almost everytime we reset it. What im being told is to press the HP button in the modular and then press reset on the touch-screen sensor. But yet it still trip. The discharge pressure will rise up to 1500kpa and then trip. Then It stated "FAULT --- HP" What should I check?

a. What refrigerant you are using prior to setting of your HP cut-out?
b. Is their enough water in you cooling tower?
c. Did you check if their is clogging in your line strainer going to your condenser?
d. How long do this equipment running, Old or new?

kr,
alphi

[The MG Pony]

sounds like a possible cooling water flow issue.

Inspect the towers: Clean, filled properly, right chemicals in them, good water flow?

Inspect strainers: Clean, good condition?

Check pumps: Good berrings, good power, running correct speed?

Check condensers: Clean, proper flow, head valves set correctly to refrigerant being used, balancing valves correctly set?

If all is good there, is the Hp switch set in accordance with the refrigerant in use? System free or air or moisture? If so it may have simply aged.

[icecube51]

how are the compressors related to eachother,
is it a pure cascade to build up the total power, or for different circuits???

how long are the in operation ??


Ice

[sedgy]

first test the flow switch, then test the h-p swich

[Gary]

The fact that there are tower fans off probably means the tower leaving water is down to temperature... yet compressors are cycling on high head. This tells us that the heat is not being transferred between the refrigerant and the water in the condenser.

Either there is insufficient tower/condenser water flow or the condensers are scaled.

Does each compressor have it's own condenser?

[Bart Nabbe]

Well, it seems a realy simple case if you say high pressure en condensor not working on max but that would be too easy.

Wat is the in and outlet temp. on the condensorwater? what is the delta T.

And in this case as others mentioned check all filters in your water system.

My advice, don't try to reset the HP alarm to much before you find anything else.

Greets,

Bart

[Grizzly]

Fir
Welcome, It may be me being silly but I don't come across many chillers that have HP trips set as low as 1500kpa.
Is it possible that you have a tired HP switch.
Or should it really trip at 1500 kpa
Have you tried a gauge on the system to see what discharge pressure you are actually pulling?
Grizzly

[bruceboldy]

We deal with Multistackon a regular basis
The units are modular all tied to a common chilled wated system and a common condneser water system. Since each multistack module uses a brazed plate chillers and condneser sections I would think the condenser sections on misc modules is badly fouled. Multistack sells a clean out system for the condenser units. Check out the site for info.