PRV Calliberation problem

[bhasadu]

We have YORK (model no.: YTJ3C3E25CNJ) Centrifugal chiller.
Its vanes are NOT calliberating and its NOT running beyond 65%.
We had changed vanes motor, ACC board but problem is same.
please guide to overcome this problem.

Thanks in advance.

[Nik BG]

Hi Bhasadu.
I've been on J4 and J3, but honestly, i have never seen them on normal operation PRV opened more than 70%. Do you reach the set point? How are the pressures? See the liquid level. How much is HGBy-pass v/v opened.I ask because everything is complex and connected. Can you open it manualy 100%?By the way you can calibrate by means of the levers, and in fully closed position of PRV on the display you should see 5-6%. That's because vanes are never totaly closed, even in end position.