York yts l-a-h screw compressor

[stufus]

Evening Gentlemen
I'm on the mooch for a teardown manual for the above compressor.
And due to politics am unable to approach JC Ireland.
If you watch the attached video ,feel free to jump to about 1:25 and wait for the clank :eek:
All and any advice or assistance will be greatly appreciated and could result in virtual beer's and donuts.
I suspect the slide is getting shot back and striking the discharge end housing but I'm not to sure.
http://www.youtube.com/watch?v=DHM5re2xmjk&context=C4225b48ADvjVQa1PpcFNrjnvbdXJXT6EumXLMBjBxmqKQ44IBYwQ=

I (http://www.youtube.com/watch?v=DHM5re2xmjk&context=C4225b48ADvjVQa1PpcFNrjnvbdXJXT6EumXLMBjBxmqKQ44IBYwQ=)'ll get better video of longer operation and post later with controller view's of running conditions.

Cheers
Stu

[monkey spanners]

Sounds like its got a cow stuck in it, theres a moooo noise then the gate goes clang! hth :D

[stufus]

Cheers MSThat clears that up . You being the bovine specialist and all.
cheers
Stu

[Grizzly]

How about non return valve in the discharge sticking, causing the rotors to spin back wards.
Then as the pressures move towards equalisation the non return snaps shut?
Just a guess!

However you theory could be correct.
Slide valve position indication should clarify.

Having thought about it some more stufus, I am not sure there is a non return valve on those units?
(I will have to ask a friend).
In which case the side valve could be as you say sticking?
So as the pressures equalise the piston could well be snapping back?
Grizzly

[stufus]

I reckon the NRV is sticking Grizzly but the "clank" is not far off what you'd get if someone smacked the comp body with a sledge.
The whole compressor is jarred.BUT...it doesn't happen every time.
Will keep all interested parties posted.
AND MANY THANKS TO THE ANONYMOUS TIPSTER;)

Beer and donuts will only be released on date of successful diagnosis:p

Cheers
Stu

[stufus]

Ok gents
Didn't bother with a new video as nothing to gain from it.
Now , have put it through all stages of loading and unloading from start to stop.
The only anomaly I have found other than the clank is the solenoid on the oil cooling circuit is not seating closed everytime..
Could this be the root cause of the issue??? as the way i'm looking at it is ,a direct path for discharge pressure back to the compressor while the comp is trying to equalise on shut down.
At this stage I'm more interested in the cause ,and am resigned to quoting mechanical damage on the report.
Again all and any opinions welcome ,so long as no one mentions bleeding Endocube's
Cheers
Stu

[Grizzly]

I promise no e's stufus.
You may have something there with the solenoid valve,as I think that model comp may well have an integral oil separator?
If so it must be some form of coalescer (Can't spell it ) however the oil is removed and recirculated to the compressor via the oil cooler circuit.
I guess it's safe to assume the wrong bit is getting pressurised as you say.

I think there may even be a non return valve in the oil off side of the oil cooling line.
Forget the statment in italics a confused bear wrote them.

I hope you are not liable for the warranty?
Grizzly

[chillerman2006]

Again all and any opinions welcome ,so long as no one mentions bleeding Endocube's
Cheers
Stu

Stu

I'm waiting for your video of strip and rebuild, so you can educate me

But dont right off the magic of Endocube, it could increase your run time and lower those enormous amount of starts;)

R's chillerman

[stufus]

Endocube my bollox!!!!HAHA I'll post a teardown and rebuild video as soon as I find one online....because sure as fook I'm not doing it.So yourself and Monkey Spanners will have to wait
StuI'm waiting for your video of strip and rebuild, so you can educate meBut dont right off the magic of Endocube, it could increase your run time and lower those enormous amount of starts;)R's chillermanWarranty has nowt to do with me Grizzly ,Have been maintained by suppliers for last five years ,so probably out of warranty either way.As I said more for my own peace of mind before I drop the bomb on the client so to speak.It won't do it every time even if the valve is closed so I'm guessing that there could be a slight delay in the valve seating that may cause it to occur intermittently.Or that it will occur within a certain pressure band due to seal damage....But screws are not my forte.Thanks again gentsCheersStu

[centrifs]

stu, is she shutting off fully loaded? have you checked the slide valve unload. what model chiller what model comp. DXS comp on a YCAS? Griz that looks like an oil sep at the beginning of video

[stufus]

The Chiller model is YAES0715S9 50Y Q-PACK
The comp model YTS L-A-H.
The compressor is a rebranded Hanbell RC20
She is unloading checked, all the obvious stuff.
It's been left isolated for the moment until a bigwig makes a call on it.
Cheers
Stu

[RANGER1]

stufus,
I f you go to Hanbell web site you can download manual on this one.
Oil seperator is just baffles & mesh inside, coalescer is usually a seperate vessel in discharge line mounted in main discharge after your compressor oil sererator. Can't see anything would make noise in it.
Like everone says discharge check valve.
Also I don't think slide valve could move that quick, not sure if there is a speed rate adjustment on unloading, but has capiliary tube feeding oil to it for load up.
Do you have another package to compare how unit shuts down, paying particular attention to machine spinning backwards.

[stufus]

Two chillers side by side which is four circuits ,and the only discrepancy was the oil valve . No load at the moment as the Irish weather is good like that. ,So isolating it was not an issue.Will eventually get pinned on the maintenance contractor ,but curiosity has gotten the better of me.
As I said screws are not my forte..
Cheers
Stu

[Magoo]

Hi Stufus,
had similar problem with a stal screw, same back spin same clang noise. Result was the discharge check was a pressure sustaining combo valve, that should be only open "X "number of turns not fully opened.

[mark957]

I think that the mechanical noise may depend on the capacity control piston which may have increased tolerance, while the noise of the vine and clap stop counting EQ compressor depends on the gas from the oil separator, which returns to the intake valve closing and not to return after the separator.