Technical data

CHAP-04.11 AUTOMATION
Page 12 of 15
automation permission. For this purpose, specific menu will be
provided with operator workstation for such drives.
15. Local De-interlock mode of operation will be used only for
adjustment, maintenance and testing purpose. After the selector
switch at MCC / MCP is selected to Local De-interlock mode and
Operator/PLC permission is obtained from Control room, the
drives/valves can be started/opened/closed from Local control
stations using start/open/close push buttons. Under this mode of
operation, all safety interlocks (Pull Chord Switches, motor over load,
Emergency switch etc.) will be provided through hardwire in the
circuit.
The stop push button provided in Local Control station will stop the
drive under all mode of operation. In case of emergency Stop, alarm
will be provided at the Operator workstation at control room to warn
the operator. Hooter PB will be provided in LCS for pre start warning.
16. Local interlock mode for running the drive in sequence interlocked
mode from LCS. Selector switch will be put in local interlocked
position and permission from operator / PLC will be pre requisite
condition. In this mode start, stop, motor over load, emergency stop,
Pull Chord & Belt Sway Switches, Zero Speed Switch, chute jamming
switches will be in the circuit through hardwire in addition to interlock
with successive conveyor / equipment.
17. Under remote mode of operation, following control modes for all
drives will be provided through Operator workstation.
i. Remote Manual
ii. Automatic
Selection of remote manual or automatic mode of operation will be
carried out using command menus through Operator workstations.
Remote Manual mode
Under remote manual mode of operation, individual drives will be
started/stopped from Operator workstation. However, necessary safety
interlocks will be provided by automation system. This mode can be
used for testing of individual drives from Control room.
Automatic mode
Under Automatic mode, the plant/equipment will be controlled,
started/stopped automatically in sequence by automation system using
various command menus from any of the Operator workstations.
04.11.04 CONTROL ROOM / DESPATCHER ROOMS
A. COAL HANDLING PLANT:-