Problem with chiller

[jure]

HI
I have a problem with 4compressor unit(2 tandem unit)-
Because comp1 and comp3 burn out we replaced them with new comp,also oil has been changed and filter driers too.
When start up was done I tried to close the both txv valves because my suction pressure was 7 bar (also head temp was very high) and I still had a lot of bubbles on glass, but the pressure did not fall.
The condenser is OK also the fan motors.
The refrigerant is R407C, Dt 4,5C and head temp now is 110C
It would be a disaster if the new comps would burn out again.

ANY CLUES

Thanks

[old gas bottle]

whats it running on ?high or low temp cold room????or what?

[tony--1]

looks like you got a lot of air in system .decant it .vac it and then regas

[nike123]

HI
I have a problem with 4compressor unit(2 tandem unit)-
Because comp1 and comp3 burn out we replaced them with new comp,also oil has been changed and filter driers too.
When start up was done I tried to close the both txv valves because my suction pressure was 7 bar (also head temp was very high) and I still had a lot of bubbles on glass, but the pressure did not fall.
The condenser is OK also the fan motors.
The refrigerant is R407C, Dt 4,5C and head temp now is 110C
It would be a disaster if the new comps would burn out again.

ANY CLUES

Thanks

What serves this unit?
What is evaporator air/water inlet temperature? What is evaporator type?
What is condenser air/water inlet/outlet temperature?

Bubbles on sight-glass with R407 is common thing, what is subcooling at TEV inlet and condenser outlet?

What is superheat now after adjustment of TEV's? Did you checked, opened and cleaned TEV's after burn-out?

Dt 4,5C

What you mean by that?
Also, what you mean by "head temp"?

[chemi-cool]

1. as Tony said >>>> AIR.

2. replace the 407, its no good for nothing.

[jure]

HI guys

This is common water chiller
Dt is delta evaporator inlet/outlet temp
Head temp is temperature on top of the compressor (head)
SSH is 9C
But the compressors are still sweating
But we didnt do the cleaning the txv(will do that
And I am 200% sure there is no air inside, pressure test was OK and vacuum was OK
About the bubbles I know there should be some due to high outside temp. but there is to many bubbles

[nike123]

HI guys

This is common water chiller
Dt is delta evaporator inlet/outlet temp
Head temp is temperature on top of the compressor (head)
SSH is 9C
But the compressors are still sweating
But we didnt do the cleaning the txv(will do that
And I am 200% sure there is no air inside, pressure test was OK and vacuum was OK
About the bubbles I know there should be some due to high outside temp. but there is to many bubbles

Few more answers expected!

What is evaporator water inlet temperature?
What is condenser air/water inlet/outlet temperature?
What is subcooling at TEV inlet and condenser outlet?

What is condensation pressure?
Also, did you charged new virgin refrigerant?
Did you charged by weight?

I see 4 possible causes of elevated suction and discharge pressures (if that is case here, but we don't have discharge pressure and condenser TD to confirm that):
1. Noncondensables
2. Overcharge
3. Faulty TXV
4. High load

Which one, or maybe it is combination, we will only know when you provide all necessary measurements and answers.

[Plank!]

sounds like air to me.

or some bad combustion products from the burn out, pull the gas, oil, filters and replace everything.
fit high cap burn out driers and replace again soon after.

[Tesla]

If all the above were checked and problem still there check these - Blocked drier, did you put in a suction line filter for clean up, if so remove it, if not check suction strainer at compressor. If welded connection on discharge - is there a restriction ( I've seen the tube close on discharge from no expansion fitting used ). I'm sure a IR thermo would help located problem area

[jure]

Hi
We will fit in a new TXV because the compressors burned out after 166 hours of work, so we suspect that the TXV is too large(factory mistake) or even not good from the start.

[Gary]

If I understand you correctly, this is an air cooled water chiller. Is that correct?

For a proper evaluation, we need the following information:

Low side:

Evap water in temp
Evap water out temp
Saturated suction temp
Suction line temp at evap outlet

High side:

Cond air in temp
Cond air out temp
Saturated condensing temp
Liquid line temp at receiver outlet

[icecube51]

About the bubbles I know there should be some due to high outside temp. but there is to many bubbles

bubles dont always mean " air" , can be flasch gas.

is the amount of gas sufficient, is it as the constructor recomends?

if you are sure of the rest, vacuum ok , filters ok ,no leaks, check the refrig by the book, take note's and check the engine.

Ice