York Millennium YK M3 M3 G4 THRU YK S6 S4 J2 - Manual (Page 36)

36 YORK INTERNATIONAL
period. EPROM version C.02F(T).12 or later pro-
vides a 10 minute coastdown period. The compres-
sor, condenser water, and cooling tower fans will
stop automatically. The oil pump will continue to run
for coastdown period. The oil pump will then stop
automatically. Once stopped, the
SYSTEM COASTDOWN display will be replaced by
SYSTEM READY TO START .
2. Stop the chilled water pump (if not wired into the
MicroComputer Control Center, in which case it will
shut off automatically simultaneously with the oil
pump.) (The actual water pump contact operation
is dependent upon the postion of Micro Board jumper
J54.)
3. Open the switch to the cooling tower fan motors, if
used.
4. The compressor sump oil heater (thermostatically
controlled) is energized when the unit is stopped.
PROLONGED SHUTDOWN
If the chiller is to be shut down for an extended period
of time (for example, over the winter season), the fol-
lowing paragraphs outline the procedure to be followed.
1. Test all system joints for refrigerant leaks with a
leak detector. If any leaks are found, they should
be repaired before allowing the system to stand for
a long period of time.
During long idle periods, the tightness of the sys-
tem should be checked periodically.
2. If freezing temperatures are encountered while the
system is idle, carefully drain the cooling water from
the cooling tower, condenser, condenser pump, and
the chilled water system-chilled water pump and
coils.
Open the drains on the cooler and condenser liquid
heads to assure complete drainage. (If a Variable
Speed Drive, drain its water cooling system. If Solid
State Starter. drain water from starter cooling loop.)
3. Move jumper J-57 on the Micro Board from CLOCK
ON position (CLKON) to CLOCK OFF position
(CLKOFF) while 115VAC control power is applied.
This conserves the battery.
4. Open the main disconnect switches to the com-
pressor motor, condenser water pump and the chilled
water pump. Open the 115 volt circuit to the Control
Center.
START-UP AFTER PROLONGED SHUTDOWN
1. When putting the system into operation after pro-
longed shutdown (during the winter), remove all oil
from the compressor. Install a new filter element
and charge compressor with fresh oil. Move jumper
J-57 on the Micro Board from CLOCK OFF position
(CLKOFF) to CLOCK ON position (CLKON) and re-
set the clock. Energize the 115 volt circuit to the
Control Center to energize the compressor sump
oil heater for at least 12 hours.
2. Operate the Oil Pump (press and release the MAN-
UAL OIL PUMP key) until steady oil pressure is
established. Then press and release the OIL PUMP
key to stop operation of the oil pump. If the water
systems were drained, fill the condenser water cir-
cuit and chilled liquid circuit.