Climaventa chiller

[monkey spanners]

Hi all,

Had a look at a 23 year old Climaventa chiller with a Hitachi screw compressor, air cooled condenser and shell and tube evaporator on R407C that cools a water loop for fan coils. Customer had been advised it was faulty and needed replacement, we turned it on and away it went cooling the loop down from 22C to 8C (ish)

Hour meter showing around 4500hrs which seems low given its age.

Anyway chillers not being my main area of expertise am after a bit of advice

With a water in temp of 12C, water out temp of 7.4C had an evaporating temp of -3.8C which seemed a bit low to me, is it too low? (water temps taken using chillers own sensors, evap temp from Testo gauges)

There is no service history for the system, have advised the plumber chaps to check and clean out any strainers in the water circuit, but am wondering if the evaporating temp is too low could this be due to flouling in the shell and tube thingy?

It was pulling around 47A per phase, data plate show a FLA of 123A so it wasn't working particularly hard at the time.

Cheers John

[seanf]

Has it got capacity control?
What was suction superheat?
Water or glycol?
Just a TEV?

[monkey spanners]

Not sure on the capacity control tbh, compressor noise didn't change when it was running.
Suction superheat was 8.8K
The guy on site didn't know if it was water or glycol, they have just taken over the contract for the site.
Yes just a danfoss TEV

To me it didn't seem to be working very hard for the size of it but I am unfamiliar with these types of systems.

[seanf]

Do the condenser fans have any stageing or speed control? were they cycling or running fast/slow.

Do you have the model no. and year of the chiller? or comp info.

[Grizzly]

Hi M.S.
A 5 degree split would be perfect. You are correct in your initial diagnosis "blocked Strainers would be my first thought. The flow through a chiller is a major factor.
Try the attached for some possible info?
Once you can identify the actual chiller I am sure someone will be able to help you further!
Good luck.
Grizzly
https://www.mediafire.com/file/58oz0aj6o93682a/BESRAT%252C_BESRAD_BESRAR.pdf/file

[nike123]

Evaporator approach is to high! That mean bad heat transfer at evaporator. Therfore you should first check that air is not trapped in evaporator. If not, then probably it is scale on evaporator tubes!
https://www.youtube.com/watch?v=9OIMqqSC9i8

[seanf]

If it was only water in the circuit, and with it being shell and tube. Would a coating of ice give an insulating layer, giving poor heat transfer but also allowing enough flow to show the warmish water temps?

I'm probably talking cr4p though. Sorry.

.
.

[monkey spanners]

Thanks for the replies!

System has an external air cooled condenser, fans seem to all run at once but are speed controlled.

Climaveneta SME-0601 with a Hitachi 6005C-H compressor.

Hopefully we will be asked to look at in more depth.

[redroge]

Switch the chiller off and let the water temp.get up to 20 degrees switch on and check the loading and unload with your amp meter like the others have said sounds like a water flow problem

[monkey spanners]

It never sounded like it loaded up when we ran it, will give that a try if we get asked back, thanks!

[seanf]

Did it seem like it had enough refrigerant?

Do the older Climaveneta's limit there comp capacity when the suction pressure goes low?

[GHAZ]

Hi at 100% all solenoid are denergised
75% only middle solenoid is energised
50% only top solenoid is energised
25% only bottom solenoid is energised

Air cooled compressor needs bearing change and slide valve seals change @24000 hrs