JOHNSON CONTROLS
31
SECTION 2 - PRE-STARTUP AND SYSTEM OPERATING PROCEDURES
FORM 160.67-O2
ISSUE DATE: 10/9/2020
2
STARTUP SEQUENCE OF OPERATION
1. On the OptiView™ Control Center HOME
screen, press the STEAM SYSTEM key to go to
the STEAM SYSTEM screen.
2.
On the front of the OptiView™ Control Center,
place the keypad switch in the (O) STOP/RESET
position to reset any previous safety trips. The
message SYSTEM READY TO START is dis-
played.
3. On the front of the chiller panel, place the key-
pad switch in the (
◄
) “START” position and re-
lease. This starts the compressor oil pump and
the turbine auxiliary oil pump (if equipped). The
condenser liquid pump start contacts (terminals
150-151 on the I/O board) are closed to start the
condenser liquid pump. If the operator has NOT
logged in using the OPERATOR access code, the
message "MANUAL START REQUIRES OP-
ERATOR ACCESS LEVEL" is displayed. If the
operator has logged in using the OPERATOR ac-
cess code, the message START SEQUENCE INI-
TIATED is displayed. The compressor oil pump is
started after the 13-second delay for auto-zeroing
of the differential oil pressure.
If the condenser liquid pump contacts
are not used, the plant control system or
operator must ensure that the condenser
cooling liquid flow is established within
45 seconds after these contacts are closed.
Otherwise, the low flow switch will trip
the chiller.
If for any reason, the turbine begins
rotating prior to a start sequence being
initiated, the oil pumps will be started
automatically. The condenser liquid
pump contacts are also closed and the oil
cooler liquid solenoids are energized to
provide oil cooling during this abnormal
operation.
4.
Forty-five seconds after the start is initiated, the
control logic will check that adequate compressor
oil pressure, turbine oil pressure (if Pump Lubri-
cation), and condenser liquid flow are established.
5.
Fifty seconds after the start is initiated, the main
start relay (K18 on the I/O board) is energized.
The turbine trip and vacuum breaker solenoid
valves are energized, the pneumatic turbine trip
valve is opened, the hotwell pump is started, and
the message SYSTEM STARTING is displayed
at this time.
Automatic Start: The main steam inlet block valve
and slow roll bypass valve air dump solenoids are
energized to apply supply air pressure to the actu-
ators. This enables manual operation of the valves
if required.
Chillers manufactured after December
2006 are not supplied with separate au-
tomatic main steam inlet and slow roll
bypass valves. The main steam inlet sup-
ply isolation valve should be fully open
at this time.
If the turbine trip valve fails to open
within 10 seconds after the trip solenoid
is energized, the start is aborted and the
message "TURBINE MECHANICAL
TRIP" is displayed.
During this period, before the turbine is
started, all condensate should be return-
ing to the hot well (recirculation valve is
open, overboard valve is closed).
If the chiller is equipped with an op-
tional standby hotwell pump,
in the au-
tomatic mode, the Hotwell pumps will be
switched-over (at each Chiller Start) to
share operational time. If the lead pump
fails to start or fails while the chiller is
operating, toggle to standby pump will be
done automatically. If both pumps fail, the
chiller will be not be allowed to start and
will shutdown if operating.
6.
After the turbine trip valve limit switch is closed,
the vacuum pump sealing water solenoid valve
is energized. When the sealing water flow switch
contact closes, the vacuum pump is started. When
the exhaust pressure has been reduced to 10 PSIA,
the message "READY TO BEGIN SLOW ROLL"
is displayed. Press the BEGIN SLOW ROLL key
that appears on the STEAM SYSTEM screen.
The message "WAITING FOR STEAM FLOW"
is displayed.
THE ACCESS LEVEL MUST BE DIS-
PLAYED “OPERATOR” IN ORDER
FOR THE BEGIN SLOW ROLL KEY TO
BE DISPLAYED. If the BEGIN SLOW
ROLL key is not pressed within 20 min-
utes after it appears, the turbine will be
tripped and the message "EXCESSIVE
START DELAY" is displayed.