York Millennium YK M3 M3 G4 THRU YK S6 S4 J2 - Manual (Page 34)

34 YORK INTERNATIONAL
YORK office. Automatic data logging is possible by
connecting the optional printer and programming the
DATA LOGGER function; refer to Form 160.49-N7.
An accurate record of readings serves as a valuable
reference for operating the system. Readings taken
when a system is newly installed will establish normal
conditions with which to compare later readings.
For example, an increase in condenser approach tem-
perature (condenser temperature minus leaving con-
denser water temperature) may be an indication of dirty
condenser tubes.
OPERATING INSPECTIONS – See Section 2
By following a regular inspection using the display read-
ings of the MicroComputer Control Center, and main-
tenance procedure, the operator will avoid serious op-
erating difficulty. The following list of inspections and
procedures should be used as a guide.
Daily
1. Check MicroComputer Control Center displays.
2. If the compressor is in operation, check the bear-
ing oil pressure by pressing OIL PRESSURE key
to read the display on the Control Center. Also check
the oil level in the oil reservoir. Operating oil level
should be between the upper and lower sight
glasses. Drain or add oil if necessary.
3. Check entering and leaving condenser water pres-
sure and temperatures for comparison with job de-
sign conditions. Condenser water temperatures can
be checked by pressing CONDENSER LIQUID
TEMPERATURES display key.
4. Check the entering and leaving chilled liquid tem-
peratures and evaporator pressure for comparison
with job design conditions. This can be accomplished
by pressing the CHILLED LIQUID TEMPS key and
the REFRIGERANT PRESSURES key.
5. Check the condenser saturation temperature (based
upon condenser pressure sensed by the condenser
transducer). Press the DISPLAY DATA key. This
key may be depressed repeatedly after depressing
the DISPLAY HOLD key to display three different
parameters.
6. Check the compressor discharge temperature.
Press DATA DISPLAY key. During normal opera-
tion discharge temperature should not exceed 220°F.
7. Check the compressor motor voltage and current
(amps) at E-M starter (or Variable Speed Drive), or
on the Control Center display for Solid State Starter
units.
8. Check for any signs of dirty or fouled condenser
tubes. (The temperature difference between water
leaving condenser and liquid refrigerant leaving the
condenser should not exceed the difference re-
corded for a new unit by more than 4°F.)
9. Press the STATUS key whenever the display indi-
cates so. This allows any warning messages to be
displayed.
Weekly
1. Check the refrigerant charge. (See “Checking The
Refrigerant Charge”, page 52.)
Quarterly
1. Perform chemical analysis of oil.
Semi-Annually (or more often as required)
1. Change and inspect compressor oil filter element.
2. Oil return system.
a. Change dehydrator.
b. Check nozzle of eductor for foreign particles.
3. Check controls and safety cutouts.
Annually (more often if necessary)
1. Drain and replace the oil in the compressor oil
sump. (See “Charging The Unit With Oil”, page 43.)
2. Cooler and Condenser.
a. Inspect and clean water strainers.
b. Inspect and clean tubes as required.
c. Inspect end sheets.
3. Compressor Drive Motor (See motor manufactur-
ers maintenance and service instruction supplied
with unit)
a. Clean air passages and windings per manufac-
turers instructions.
b. Meg motor windings – See Fig. 23 for details.
c. Re-lubricate ball bearings.