View Full Version : York YSDC
08-28-2009, 08:51 PM
I am an owner of an commercial HVAC business in Nashville, I am not an chiller expert but have several years with Trane in Nashville some 20 some years ago so I understand the concept. I had a prior customer who works else where now as a maint eng fo several office buildings. He called me today to stop over and meet him and look at a chiller that he feels he is getting the shaft from the so called compentant mechanical contractor who servicing the account. They were told that a changeover valve that isolates the oil filters for service would not hold and was bad, the valve was replaced, I saw the old one in the floor. Now it will not make capacity when temps are hot. They have been on several calls and still not right. I think it is low on charge, they put back what was removed. Th IOM is very vague, leave chiller off 4-6 h and sight glass should be 2/3 full on evap barrell, is this correct. The full number is YSDCCBS3-CMC. I am not going to be working here, low price wins for these people. I am just helping a friend, he doesnt call the shots as who gets the work.
08-28-2009, 10:16 PM
Based on the M/N that you gave the info. that I have would be 840 lbs full charge. The other info. about checking the refrigerant level would be let the machine stabilize pressure and temperature from 4hrs to longer with all pumps CHW & CW stoped the level should be half way on the upper sight glass as per the IOM.:LOL:
08-28-2009, 10:20 PM
The evap barrell has only one sight glass on the left end.
08-28-2009, 10:53 PM
I don't have the full service manuel book in front of me at this time will be a few days because I am away for me to check further. Did they ever pull the charge if so did they weigh it. There are two styles one with single sight the other with double sight glass.
08-28-2009, 11:32 PM
To check static charge with the evap glass, both barrels must be at the same temp. Preferably 24 hour shutdown, and valved out. Otherwise, any pressure gradient will cause fluctuation in level, sometimes severely. If this can't be done, best way is to look at approach on the evaporator with the chiller running as loaded as possible. 2 to 4 degrees approach, low to mid 30's on discharge superheat at full load. Static tests using sight glasses have a way of lying to you.
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