Saturday, May 10, 2014

Siemens Control system components

Control System Components
  V  1.3
Control system components
m  Operator Interface
m  Controls Cabinet
m  Terminal Rails
m  Allen Bradley CLogix chassis
m  MK2 controls chassis
m  Interface modules
m  Controlnet
m  Overspeed Protection
m  Emergency stop loop
m  Motor Control Centres
Operator interface
l  VDU, keyboard and pushbuttons
l  VDU often touchscreen
l  Sometimes mounted remotely to controls cabinet
l  Keyboard slides or hinges out of controls cabinet if VDU on controls cabinet
l  Pushbuttons soft-wired, time delay applies.
Controls Cabinet
l  Contains Control system hardware
l  Terminal rails around the bottom half
l  Control chassis in top half
l  Vent fan used to cool controller
l  Cable entry via gland plate in bottom
Terminal Rails
l  Terminal rails numbered as per contract drawing
l  Generally all Fire and Gas on one rail
l  All DC supplies on another rail
l  Other rails house interface modules for I/O
Allen Bradley PLC controller
l  Control chassis mounted inside UCP
l  Normally 13 slots plus power supply
l  PSU on the left followed by cards
l  PLC processor is Logix 5555 for package and sequence control
l  SAM module for core engine control (fuel and air)
l  Other cards are comms or local I/O
l  Most instrumentation is connected via Controlnet.
MK2 controller
l  Up to 4 control chassis mounted inside TCM
l  Up to 15 cards in each chassis
l  I/O cards such as AIM’s, SIM’s, FIM’s
l  PPM for package, sequence and core engine control
l  CEC often run in separate utility within PPM (BEACON)
l  I/O connection via IFM’s or Controlnet
I/O interface
l  Interface modules, IFM’s, are used to make the field signals compatible with the card input
l  Provide external relays
l  Provide interface from ribbon cable
l  Lots of types
l  I/O network made by Allen Bradley
l  Lots of I/O transmitted over a single network cable
l  Dual redundant
l  Reduces field wiring
l  Reduces control system cards
l  Can be in controls cabinet or field mounted
Overspeed protection
l  Separate Overspeed protection
l  Mounted in control cabinet
l  Uses MK2 OSM
l  Also provides watchdog for processor
Emergency stop loop
l  Emergency stop pushbuttons around skid
l  And at the TCM
l  And remotely (customer)
l  Hardwired system
l  Inputs from overspeed and Fire and Gas
l  Removes power from the Fuel block and vent valves
l  Latched relay, reset-able from control interface
Motor Control Centres
l  MCC’s
l  Low voltage output from controls activates contactor to put higher voltage onto motor
l  Selectable to Local or Auto
l  Overload protection
l  Lamp indication on front panel
l  IDS generally shows demand not feedback
Generator Control Panel
l  GCP, external supply
l  Generator protection, monitoring and synchronising control
l  Modern systems have a processor based protection relay
Fire and Gas chassis
l  HOW fire and Gas (Tyco)
l  Aternative Detronics or Allestec systems are also used
l  Mounted in control cabinet
l  Gas cards
l  Zone cards (UV’s, Heat detectors, MAC’s)
l  Extinguishant cards
l  Common controller
Vibration monitoring
l  Vibration chassis
l  BN3500
l  Vibration data sent to controller via MODBUS comms
l  Alarm and Trip data sent by hardwired relay outputs
VGV ram control
l  Hydraulic VGV ram controlled by an ATOS unit
l  Converts control system signal to signal required to drive the ram
l  Requires calibration/setup
l  Electric VGV ram controlled by a Moog driver unit
STAR system
l  Small Turbine Advanced Retrofit
l  Throttle valve control system
l  Actuator and ball valve
l  ECU provides control
l  May have external feedback potentiometer
lElectronic Control Unit
lUsed to position fuel valves and sometimes VGV ram
lIn retrofit applications on some engine types can be used to govern the engine
lMounted onskid, offskid or in control cabinet
lCommunication with controller by RS485 or Devicenet comms
lIf RS485 also some hardwired signals
Integrated Fuel Valve
l  Model E Gas Fuel system packages
l  Modular fuel valve system
l  Comprises Block and vent valves, throttle valves, ECU and instrumentation
l  Single I/O network connection
Batteries and charger
l  Lead Acid & NiCad batteries are used to provide backup power to the TCM
l  During normal operation an Inverter takes supply voltage and feeds a battery charger
l  The battery charger constantly charges the batteries
l  The TCM is normally supplied from the battery charger, in the case of power loss the batteries provide power to the TCM
Control system components
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