17
PIC 5 CONTROL OPERATION
Start-Stop Control —
This function controls the chiller
START-STOP command. The four selectable control modes
are as follows: LOCAL, LOCAL SCHEDULE, REMOTE, or
NETWORK. See Unit Start/Stop Screen on page 14. Specific
control sources are valid to start or stop the chiller for each con-
trol mode.
LOCAL — When the control mode is LOCAL, the chiller can
be started by the “Local ON” button on the PIC 5 interface
screen, and can be shut down by the Confirm Stop button on
the screen or by the EMSTOP software point.
LOCAL SCHEDULE — When the control mode is LOCAL
SCHEDULE, the chiller will be started automatically if the
configurable local schedule is Occupied. The chiller can be
shut down by the unoccupied schedule, the Stop button on the
PIC 5 interface screen, or by the EMSTOP software point.
REMOTE — When the control mode is REMOTE, the chiller
will be started by the remote discrete input (REM_CON) locat-
ed on the I/O board. The chiller can be shut down by the re-
mote discrete input, the Stop button on the PIC 5 interface
screen, or by the EMSTOP software point.
NETWORK — When the control mode is NETWORK, the
chiller can be started and stopped by the CHIL_S_S and
CHIL_OCC software points, which are written by other equip-
ment through network commands and network schedule (both
must be TRUE for chiller to start). To shut down the chiller, use
the EMSTOP software point or stop using the HMI.
NOTE: There is a STOP OVERRIDE point in the GENUNIT
table. If this point is enabled the chiller cannot be started.
Compressor Run Status —
Compressor run status is
shown at the top of the system overview (home) screen. Table
11 lists the chiller status numbers, names, and descriptions.
Economizer Status
Damper Control Type
Target Damper Position
Actual Damper Position
Economizer Pressure
Evaporator Pressure
Pressure Difference
a19-2310
Fig. 26 — Economizer Status
NOTE: The pressure difference shown in this screen is the differ-
ence between economizer pressure and evaporator pressure.
Transmission Status
Oil Sump Temperature
Oil Pressure Difference
Oil Pump
Oil Supply Temperature
Oil Heater
Low Speed ME Brg Temp
High Speed ME Brg Temp
Low Speed CE Brg Temp
High Speed CE Brg Temp
a19-2305
Fig. 27 — Transmission Status
VFD Status
Target VFD Frequency
Target VFD Speed
VFD Running Status
Actual VFD Frequency
Actual VFD Speed
VFD Fault
VFD Load Current
a19-2311
Fig. 28 — VFD Status
Fig. 29 — Envelop Control /HGBP
(Hot Gas Bypass) Status