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sensek75
19-06-2013, 04:29 PM
Hi
We having bitzer chiller for - 30 deg , in this chiller we are not able to go beyond -15 deg c also the expansion valve body getting ice frosting very frequently


Pl help me


Sekar

1mikeefc1
19-06-2013, 05:42 PM
Sounds short of refrigerant.

sensek75
20-06-2013, 05:27 PM
Thank you for your information

The MG Pony
10-07-2013, 02:32 PM
Hold it that is a poor statement with out more data! never NEVER NEVER assume low refrigerent right away! bad practice!, what is the sub cooling on the txv and the Super heat, air in and air off condenser, only after we analyze the system can we question the gas charge!

1mikeefc1
10-07-2013, 06:45 PM
It is not a poor statement at all it is a fact that frost on the body of a tev is a symptom of short of refrigerant I agree with a previous post of yours saying its not always gas but symptoms are how we find faults until further information is provided there is nothing else to go on.

passandscore
11-07-2013, 04:21 AM
sensek75,

A little light reading.
http://www.emersonclimate.com/Documents/FlowControls/PDF%20resources/2006FC-174R1TXVre-article.pdf

passandscore
11-07-2013, 04:46 AM
Sekar,

What's the temperature of the space that the TXV is in? I'm sure it is above 0c, seeing as it is a chiller and not an air coil. The refrigerant is well below 0c (freezing). So if that's the case, the frost that you are seeing is nothing more than the water vapor from the surrounding air freezing to the outside of the valve.

Correct me if I'm wrong.

As for not being able to get below -15c, is it possible that you have too much load on the chiller? Is the flow rate correct?

1mikeefc1
11-07-2013, 07:44 PM
Sekar,

What's the temperature of the space that the TXV is in? I'm sure it is above 0c, seeing as it is a chiller and not an air coil. The refrigerant is well below 0c (freezing). So if that's the case, the frost that you are seeing is nothing more than the water vapor from the surrounding air freezing to the outside of the valve.

Correct me if I'm wrong.

As for not being able to get below -15c, is it possible that you have too much load on the chiller? Is the flow rate correct?
I would say the ice build up on the tev must be abnormal for him to notice it and that on top of the struggling to reach temp would point me in the direction of a short of refrigerant diagnosis, obviously this is different to actually seeing the equipment so can only go off his symptoms.