Quantech QWC4, Installation Operation & Maintenance, Page: 132 / 156

QUANTECH
132
FORM QWC4-NM1 (221)
ISSUE DATE: 02/28/2021
SECTION 7 - MAINTENANCE
DAILY OPERATING INSPECTIONS
Routine Inspections
Avoid serious operating difficulties by conducting reg-
ular inspections. Use the following list of daily inspec-
tions and procedures as a guide.
Check or verify the following:
1. Control center displays.
2. If the compressor is in operation,
c. Check the oil pressure.
d. Check the oil level in the oil reservoir.
e. Drain or add oil, as necessary.
3. Entering and leaving condenser water pressure
and temperatures for comparison with job design
conditions.
4. Entering and leaving chilled liquid temperatures
and evaporator pressure for comparison with job
design conditions.
5. Condenser saturation temperature (based upon
condenser pressure sensed by the condenser trans-
ducer).
6. Signs of dirty or fouled condenser tubes. (The
temperature difference between water leaving
condenser and condenser refrigerant saturation
should not exceed the difference recorded for a
new unit by more than 4°F (2°C)).
7. Compressor discharge temperature. During nor-
mal operation, discharge temperature should not
exceed 212°F (100°C).
8. Compressor motor voltage and current (amps) on
the control center display.
9. Proper water treatment.
Press the STATUS key whenever the display indicates
to do so, which allows any warning messages to be dis-
played.
COMPRESSOR OIL
Check Operational Oil Level
The compressor requires 2.4 gal (9 L) of YORK L oil.
Oil Level
The QWC4 chiller DOES NOT HAVE an oil pump.
System oil flow is dependent on the pressure differen-
tial between the condenser and evaporator. Therefore,
the oil flow rate, and oil level in the separator will vary
as the system pressures and compressor speeds change.
It is normal for the oil level to be at the bottom of the
lower sight glass, or near the top of the upper sight
glass on the oil separator, depending on conditions.
Do not add oil unless the oil level cannot be seen in the
lower sight glass when the compressor is operating at
least 100 Hz. At lower loads, oil level may be below
the lower sight glass, but with the proper amount of oil
in the chiller, an adequate amount of oil is provided to
compressor at those loads even with partial refrigerant
in the stream. Oil should not be removed unless the oil
level is above the upper sight glass. If oil needs to be
added, use the procedure below to manage the oil level.
Do not add oil unless the oil level can-
not be seen in the lower sight glass, or
removed unless the oil level is above the
upper sight glass. If oil needs to be added,
use the procedure below to manage the
oil level.
Start-Up
1. Oil level cannot be seen in the lower or upper
sight glass: For chillers shipped with a factory
charge of oil and refrigerant with no oil level ob-
vious at start-up, a qualified technician should add
only enough oil to create a visible level in the bot-
tom of the lower sight glass.
Start the chiller and run a load condition between
65% and 80% FLA for a minimum of one hour
and observe the oil level. The oil level should
become visible in the lower or upper sight glass,
depending on conditions. A qualified technician
should then remove the approximate amount add-
ed to start the chiller.
2.
Oil level is above the upper sight glass:
Con-
ditions can exist where the evaporator pressure
is higher than the condenser pressure, which oc-
curs when the evaporator (or chilled) water loop
is warmer than the condenser (or cooling tower)
water loop, which can cause refrigerant in the oil
separator to condense, creating a liquid level (oil
and refrigerant mixture) that exceeds the top of
the upper sight glass.
When the chiller motor is not running, a quali-