York YMC2 A, Operation And Maintenance

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JOHNSON CONTROLS
24
Form 160.78-O1
Issue date: 05/19/2021
Section 3 - Maintenance
Maintenance inspections for YORK YMC
2
chillers
To avoid serious operating difficulty, follow a regular
inspection procedure. Use the following list of inspec-
tions and procedures as a guide.
Daily
• Check the OptiView™ Control Center display.
Log the date, time, run hours, and number of
starts.
• Use the daily log in the YMC
2
centrifugal liquid
chiller log sheet, Form 160.78-MR1 , to log all of
the unit operating data that is outlined in the log.
Use this data for the following comparisons:
• Compare the entering and leaving condenser
water temperatures with the job design con-
ditions. Check the condenser water tempera-
tures on the System screen.
• Compare the entering and leaving chilled
liquid temperatures and evaporator pressure
with the job design conditions. Check the
chilled liquid temperatures on the System
screen.
• Check the condenser saturation temperature
on the System screen. The condenser satu-
ration temperature is based on the condens-
er pressure that is sensed by the condenser
transducer.
• Check the compressor discharge temperature
on the System screen. During normal opera-
tion, the discharge temperature does not ex-
ceed 220°F (104°C).
• Check the compressor motor current on the
Compressor screen.
Weekly
• Check the refrigerant charge. See Checking the
refrigerant charge during unit shutdown .
• Check for any signs of dirty or fouled condenser
tubes. The temperature difference between the
water leaving the condenser and the saturated
condensing temperature must not exceed the dif-
ference recorded for a new unit by more than 4°F
(2.2°C).
Monthly (or more often as required)
• Log and compare the VSD input voltage current
for balanced values in the readings.
• Verify that the unit setpoints have not been
changed. Check the setpoints in the Security Log
screen.
• Verify that the evaporator and condenser water
flows are within rated limits.
• Check the operation of the motor starter. Monitor
at unit start-up for any abnormalities.
Annually (more often if necessary)
• For the evaporator and condenser, complete the
following inspections:
• Inspect and clean the water strainers.
• Inspect and clean the tubes as required.
• Inspect the end sheet.
• For the compressor drive motor, measure the mo-
tor winding insulation resistance (megohm test-
ing).
• Check and tighten all of the electrical components
as necessary
• Clean and backflush the VSD heat exchanger.
• Replace the VSD coolant.
• Perform refrigerant analysis.
• For all HYP model VSDs, conduct a Smart Sensor
annual test.
• Review the operating data for trends that indicate
increasing vibration or power consumption.