Need For Maintenance Or Service; Stopping The System; Prolonged Shutdown - Johnson Controls York YKEP Operation And Maintenance

SECTION 2 - SYSTEM OPERATING PROCEDURES

NEED FOR MAINTENANCE OR SERVICE

If the system is malfunctioning in any manner or the
unit is stopped by a safety shutdown, refer to the Opera-
tion Analysis Chart shown in SECTION 4 - TROUBLE-
SHOOTING Table 3 on Page 31. After consulting
this chart, if you are unable to make the proper repairs
or adjustments to start the compressor or the particular
trouble continues to hinder the performance of the unit,
please call the nearest Johnson Controls District Of-
fice. Failure to report constant troubles could damage
the unit and increase the cost of repairs.

STOPPING THE SYSTEM

The YKEP Control Center can be programmed to start
and stop automatically (maximum - once each day).
For more information on this refer to the YKEP Con-
trol Center Operation Manual (Form 160.77-O2).
To stop the chiller, proceed as follows:
1. Push the soft shutdown key on the homescreen of
the Control panel. The compressor will stop auto-
matically. Normal stop raises the driveline to stop
and should always be used instead of the E-Stop
during regular operation.
2. Stop the chilled water pump (if not wired into the
Control Center, in which case it will shut off auto-
matically simultaneously with the oil pump).
BRINE APPLICATIONS When the chill-
er is not running, brine should not be run
through the evaporator. However, if there
is brine running through the evaporator,
there must be flow through the condenser
to prevent tubes from freezing.
3. Open the switch to the cooling tower fan motors,
if used.
In the event of an unusual circumstance
requiring immediate stoppage, an emer-
gency stop switch is located on the side of
the control panel.
18

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 procedure should 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 system should be checked periodically.
2. If freezing temperatures are expected while the
system is idle, carefully drain the cooling water
from the cooling tower, condenser, condenser
pump, and the chilled water system pump and
coils.
Open the drains on the evaporator and condenser
liquid heads to assure complete drainage.
3. Drain the VSD cooling system and/or the Solid
State Starter cooling loop. If freezing tempera-
tures are expected for periods longer than a few
days, the refrigerant should be evacuated to con-
tainers to prevent leakage from O-ring joints.
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.
FORM 160.77-O1
ISSUE DATE: 10/22/2020
JOHNSON CONTROLS