Mcquay Centrifugal Chiller_Liq Inj

[schquenz]

Anyone got any idea oil level reducing when liquid injection ball valve open (low noise level), oil level recover when liquid injection ball valve was shut (high noise level).

[ptsac]

Anyone got any idea oil level reducing when liquid injection ball valve open (low noise level), oil level recover when liquid injection ball valve was shut (high noise level).

Liquid injection will reduce noise and cool discharge temperature. If you are losing oil it may be due to a bad "o" ring. Is the return oil temperature lower than when Liquid inj. is shut off as this would indicate liquid in oil. If this is the case the IGV will need to be stripped and inspected.
Correction.. Gear box "o" rings would be the ones to inspect.

[schquenz]

i will check it out.thanks!

[schquenz]

Liquid injection will reduce noise and cool discharge temperature. If you are losing oil it may be due to a bad "o" ring. Is the return oil temperature lower than when Liquid inj. is shut off as this would indicate liquid in oil. If this is the case the IGV will need to be stripped and inspected.
Correction.. Gear box "o" rings would be the ones to inspect.

but im stil not understand why it could be happend like this. if like what you mentioned "liquid in oil" (why not oil in liquid"..???) then it should losing oil in any condition, not related to liquid injection whether is open or shut...pls correct me if im wrong. thanks again.

[ptsac]

but im stil not understand why it could be happend like this. if like what you mentioned "liquid in oil" (why not oil in liquid"..???) then it should losing oil in any condition, not related to liquid injection whether is open or shut...pls correct me if im wrong. thanks again.

Your original question stated that this happened when the liq. inj. was on. You need to start logging some temperatures and pressures to get a picture of what changes in the two conditions.
If related to liquid inj. it maybe pressurising the gear box via a bad "o" ring, therefore liquid to oil as liquid pressure is greater than gear box pressure.

What model is this?

[ptsac]

send me your email on pm.
I have an oil loss troubleshoot guide on pdf

[ptsac]

http://hvac-talk.com/vbb/attachment....2&d=1274236727.
Copy this to your browser for pdf.
I hope this link works.

[schquenz]

Liquid injection will reduce noise and cool discharge temperature. If you are losing oil it may be due to a bad "o" ring. Is the return oil temperature lower than when Liquid inj. is shut off as this would indicate liquid in oil. If this is the case the IGV will need to be stripped and inspected.
Correction.. Gear box "o" rings would be the ones to inspect.

i found the oil return temperature when
1. with liquid injection is 45.6 C
2. without liquid injection is 47.5 C

it's quite normal which i have compared to other jobsite. But stil do not understand why oil come back when without liquid injection...?!!?!?

i have to arrange with owner to allow me to do the oil lost analysis test due to there is only damn one chiller installed.

[ptsac]

Check that charge level is correct, liquid inj. uses a good proportion of avaiable liquid. When you shut off liquid there maybe enough to achieve correct feed to evaporator. Oil return for these machines is dependent on low superheat.
Measure subcool and discharge superheat at full load with injection shut off. subcool should be 4-6C and discharge superheat should be approx 8C. There should still be a good level of subcool with inj. on.
Suction superheat should be close to 0C