york chiller not running

[cool it]

Hi I am on call this weekend and have been called to one of our sites that i havnt been to before they have a york chiller. The problem is from what i can gather something to do with oil pressure/temp.
the control panel is sayin that its calling for it but nothng is happening. the oil pressure swithch seems to be activated but the oil pressure fault light is not on.
if i press the reset it clicks but clicks agian when i loose it though it is tripping..
also the expansion valve light is saying beyond neutral zone...
Im not an expert on these chillers and any help would be appreciated.
i have left site and left chiller off and am due to go back at 5 pm GMT. if anybody can help by giving me possible things to try before then would be very glad of it.
thanks in advance...

[Donnie]

This chiller controls on superheat so if it's saying it's beyond neutral zone it means that its being called for and has not satisfied it's superheat setpoint.
This chiller also has an oil temperature inhibit sensor which prevents the chiller from starting if the crankcase heater is not working. This is located next to the crankcase heater. Check that the heater is drawing current.
You can also remove the sensor and gently heat it up to prove operation.
I hope this helps as the heater is a normal cause of failure.

[kev]

Hi Cool it,
Seems you may have a couple of faults here.
Beyond neutral zone indicates that it may be in its deadband, try adjusting the water temp to a lower seeting and/or decrease the deadband setting if its on a water chiller.

The oil trip sometimes comes on if there is a fault on the actual switch, is there sufficient oil in the sight glass on the compressor?
Sometimes, if the oil is low in the system, there is not sufficient pressure in the compressor for the switch to read before it trips.

Hope this may help a little,
Kev

[andy bailess]

Hi cool it,
I totally agree with Donnie,do not read too much in to the neutral zone area and concentrate on the oil problem,90% of these failures indicate a crankcase heater problem.On replacing that,then look into the other problem.

[wild bill]

I have had a similar problem with a YORK, YS CB CB S1 CGA that was due to the bypass valve actuator to the cooling tower not opening up fast enough to allow water flow to the tower. For some reason, the chiller would alarm off from an oil temp problem, or an oil level fault. The controller never saw the water temp. problem, it reacted on oil problems instead. Still haven't figure it out but, it's still running beautifully once we got the actuator transducer replaced which was the cause of all those problems.

[cool it]

hi guys thank you for the info.
update :- i have been back out to it and managed to get it to actually come on. It runs for about 1 min then cuts out again. then comes back in .
it isnt throwing up any faults but these are the pressures took from the display.
im not sure what they are in i think psi but i have a feeling someone is gonna tell me otherwise.
this chiller is 14 years old by the way..
SUCTION went down to 14.4
DISCHARGE was 148
OIL was around 64 - 72
is this possibly a shortage of refrigerant?
i have found out that this time last year it supposed to of had an il change and a new strainer.
could this problem if it is low suction be caused by the strainer being blocked and the previous engineer never actually changed it ?
mmmmmm we will soon see...

[DEVIL]

judging by the hight pressure it must be psi, and probably refrigerant 22 and it could be a refrigerant shortage but the worcking temperatures are important, and how fast is it going down and u should find out whay it is stoping, probably a temperature or a pressure value , it could be the antifreeze or low evaporation temp


Sorry for my english

[cool it]

hi the pressures are going down in about 20 seconds.
it is not showing a fault light on any of the pressure switches and they do work as i have checked them....
possibly a blockage ?????????

[DEVIL]

a blockage is imposible because the the pressures are low even for a normal r22 worcking system, a blockage whould give high pressure diferences, and a compressor overcurent



Sorry for my english

[Donnie]

Hi again cool it, one more thing you can look at is the water temperature sensor, sometimes they read wrong causing the chiller to over cool. Check what the sensor is reading on the diplay, remove the sensor and check the temperature with a thermometer they should be the same if not then replace the sensor,in the past i've had a few reading 2 or 3 degrees out which causes the chiller to overun it's setpoint by 2 or 3 degrees and this will give a low back pressure but not enough to cause an LP trip.

[abdulazman]

Hi COOL IT

Whats the model of the chiller?

[cool it]

i will get all the required info and post back later .
oh the water temp is 27.6 deg coming back but the chiller doesnt run for more than a min so no change in water temp !
thanks

[Robert Rumpff]

*Keep in mind, I have no experience with York chillers so I don't know how automated chiller is*
Sounds like a hot gas solenoid not opening or a liquid line solenoid not opening or both.

What are your set points?

If your target temperature is 40 degree chilled water I would expect to see between 40 and 50 psi on the low side, even a little higher on start-up.
145 - 150 on the high side is okay on start-up.

[slingblade]

hi guys thank you for the info.
update :- i have been back out to it and managed to get it to actually come on. It runs for about 1 min then cuts out again. then comes back in .
it isnt throwing up any faults but these are the pressures took from the display.
im not sure what they are in i think psi but i have a feeling someone is gonna tell me otherwise.
this chiller is 14 years old by the way..
SUCTION went down to 14.4
DISCHARGE was 148
OIL was around 64 - 72
is this possibly a shortage of refrigerant?
i have found out that this time last year it supposed to of had an il change and a new strainer.
could this problem if it is low suction be caused by the strainer being blocked and the previous engineer never actually changed it ?
mmmmmm we will soon see...

Mmmmmmm... in a word NO. a blocked oil strainer can never cause a low suction, only low oil pressure. if you deduct 14.4 form 64 - 72 {?} you have 50 to 60 psi oil pressure which concludes that the oil pump and strainer are fine.
suction 14.4 del 148 water temp @ 30 deg c. without seeing it im 99.9999999% sure its short of gas. the discharge should be 250 ish and the suction should be anywhere from 70 to 100 psi at that temp assuming R22.

[al]

Cool it

The fault is with the liquid line solly not opening, it sits beside the electronic valve and they regularly burn out. if will alarm on oil as the override on the low pressure alarm is longer than on the oil fault.

no other fault light will come on as it's doing what it thinks it should:o

All readings are in psi as these chillers weren't produced after 1990 i think.

al

[Brian]

Cool It,

What is the model and serial number of the chiller?

Thank you

[marley821]

Sling blade is right, decant it you will probably find it wont take long, and get it pressure tested, wouldnt surprise me in the least if it had a coil leak, especially if its an old GS chiller which it sounds like.

[slingblade]

Cool it

The fault is with the liquid line solly not opening, it sits beside the electronic valve and they regularly burn out. if will alarm on oil as the override on the low pressure alarm is longer than on the oil fault.

no other fault light will come on as it's doing what it thinks it should:o

All readings are in psi as these chillers weren't produced after 1990 i think.

al

I see what your reasoning is but if the sol v/v was goosed then the unit would be permenantly pumped over after the first few starts. valve plate problems aside.

[cool it]

hi sorry for the delay
details are
YORK GS
MOD NO- ycwas-75m50 95
1992
R22

I have been there with a york engineer today, we have pulled the gas out and recovered nearly a full charge. We are going to replace the solonoid valve and bypass valve recharge with fresh gas then take it from there.
we changed the driers although they were not that bad at all considering..
we have suspicions of the evaporator being knackered.
it is a very hard water area. but will not no untill we have it charged and the new parts on and see how it performs then..
will keep u updated...
thanks for all advice so far..;)

[jamcool]

hello coolit,
cannt u pull the ends on the evap. and maybe rent a bore-us-scope (hope thats the spelling) a fiberoptic video tube that u can use and look down the tubes;) if there is a thought that the tubes might be on their way out?

[slingblade]

I have been there with a york engineer today

LOL. twice the headscratching, four times the invoice.

[DEVIL]

i don't realy thinck it is a valve problem, becuase it whould make a big anomaly in pressure's and the only anomaly is that thay are bouth very low , u should find out whay is it stoping first, overpressure, low pressure, temp sensors, or compressor overcurent