York YCAV Lattitude

[ping]

I have 2 chillers that have 4 comp. each. they have the "High IPLV Capacity Control" option installed. This starts all 4 comp. at start up to bring down chill water in a quick manor. When it starts it brings water temp down to set point which is 44. it then reduces the drives to 50 hz which is min. at 105 deg. At that point as my chill water temp. continues to drop it should turn a comp off.
All comp. continue to run until me chill water temp reaches 41.9, as my return temp is 43. At this point the chiller cycles off all 4 comp. and goes into anti recycle. then starts all 4 comp. again and continues to run all 4 and shut down all 4. Thank you for any help.
PING

[ping]

Well, ive had several looks but know input so just thought id give a little update on what York is telling me. They are saying that this chiller goes into a high amb. mode at 105 OAT, and its normal to see this condition. It will come out of this mode at 100 Deg. OAT for 1 hour. well i ran it thru this senerio and it didnt come out of it after 3 hrs at 95 deg. OAT. So not real sure of this "HIGH AMB. MODE". I havent seen anything on this in writing so im trying to get more help from factory. Anyone seen or heard of this?

[DFZ]

what is design flow for the chiller and what is being pushed through it during this issue, too little flow will do the same thing, temp dropping faster than unload timers.

[ascj]

I have 2 chillers that have 4 comp. each. they have the "High IPLV Capacity Control" option installed. This starts all 4 comp. at start up to bring down chill water in a quick manor. When it starts it brings water temp down to set point which is 44. it then reduces the drives to 50 hz which is min. at 105 deg. At that point as my chill water temp. continues to drop it should turn a comp off.
All comp. continue to run until me chill water temp reaches 41.9, as my return temp is 43. At this point the chiller cycles off all 4 comp. and goes into anti recycle. then starts all 4 comp. again and continues to run all 4 and shut down all 4. Thank you for any help.
PING

What kinda of time frame are we talking? And why the low ewt? What happens if you switch off a comp or 2?

[ping]

Water flows are good and dont change when this occurs. water temp is not dropping to fast its at 42 deg for at least 20 minutes before it hits 41.9 for 30 seconds and cycles entire chiller

[ping]

the low water temp is because it is at a data site and they have redundant but in the spec. the have the high iplv option that brings all 4 comp. on to bring water down fast on start up or after power outage. it is loading up and the unloads the comp down to 50 hz just fine but wont cycle a comp. all the time. york is telling me it is going into 'HIGH AMB. MODE" and should come out of it when amb. gets below 100 for an hour. my prob is i have no literature to back this up and when i installed a potentiometer in place of oat senser and ran it to 106 it went to the high amb mode, but i turned oat down and it didnt come out of the mode like they said it should. im trying to find out if anyone has any or seen any info on this STEALTH "HIGH AMB. MODE"

[synergy]

Mr Ping, I typed in IPLV capacity control in google search and the manual came right up. I read it and the control scheam is pretty complicated. You should read it.

[york56]

IPLV is an abbreviation for Integrated Part Load Value. Like the EER, the IPLV rating was developed by the Air-Conditioning and Refrigeration Institute. (In 1998, the ARI released a revised Standard, ARI 550/590-98 to cover IPLV.) Unlike the EER, however, the IPLV measures the efficiency of air conditioners under a variety of conditions -- that is, when the unit is operating at 25%, 50%, 75% and 100% of capacity and at different temperatures.

[ping]

I have the manuel that talks about the IPLV. im looking for something that talks about the "HIGH AMB. MODE" Factory says at 105 deg it goes into this mode and will not cycle single compressors due to over heating. instead it cycles the whole machine which consists of four comp. cycling on and off

[synergy]

The attached manual explaines the high ambiant iplv control. Page 29