Plant Controls

Front 1

The four levels of hierarchy control for every pice of equipment

Back 1

PCC control

ACC control

MCC control

Local control

Front 2

PCC

Back 2

Process Control Center cancontrol nearly every piece of machinery in our plant. However, it should be notedthat the PCC cannot control the manual valves or gating needed for many processreconfigurations, nor troubleshoot equipment problems in the field. That’s the job ofa line Operator.

Front 3

PCCS

Back 3

Process Control Computer System - The main computer system atSRWTP. The PCCS computer can control or get a reading from virtually everypiece of automated equipment in the plant. Under most circumstances Operatorsin the PCC will control all plant processes from their location using the PCCScomputer .

Front 4

ACC

Back 4

Area Control Center – Each area of the plant has its own centralizedcomputer specific to that particular part of our process. Field indicators forequipment report first to the ACC computer, then to the main PCCS computer.

Front 5

PCCS Drop

Back 5

In every ACC there is a “PCCS drop,” or local PCCS computerscreen. When Operators sign on to this local computer they are able to takecontrol of equipment reporting to the PCCS computer system all in every area ofthe plant.

Front 6

Panelview

Back 6

“Panelview” controls were intended modernize each ACC the timethey were installed. By paging through the view screens you can operate certainmajor pieces of equipment specific to that plant process. Currently most of thesepanels are not used.

Front 7

MCC

Back 7

Motor Control Center – These are rooms located in each process area thatwill electrically disconnect the individual pieces of equipment related to a particularprocess from our plant’s power grid. The MCC is where you “lock out” a piece ofequipment if it fails, requires maintenance, or needs to be reset during your shift.

Front 8

Local Controls

Back 8

This means you have some sort of an on/off/ready, forward/backor start/stop switch located right next to the piece of equipment that will take it outof computer control, allowing you to run it as you please. It’s always a good ideaafter locking a piece of equipment out at the MCC to “bump test” it locally to makecertain that it will not start automatically while you’re working on it.

Front 9

FIT

Back 9

Flow Indicator Transmitter – This unit is essentially a flow meter thatgenerally reports to an ACC computer first, then to the PCCS computer. In all plantprocesses an FIT usually reports to an FIC.

Front 10

FIC

Back 10

Flow Indicator Controller - Using the readout from an FIT, you canusually control flow through a particular piece of equipment using an FIC locatedin a Process Area’s ACC, or directly from the PCCS computer.

Front 11

LIT

Back 11

Level Indicator Transmitter - This unit is essentially a level indicator thatgenerally reports to an ACC computer first, then to the PCCS Computer. An LITusually reports to an LIC.

Front 12

LIC

Back 12

Level Indicator Controller - Using the readout from an LIT, you canusually control level for a particular piece of equipment using an LIC located in aProcess Area’s ACC, or directly from the PCCS computer.

Front 13

PIT

Back 13

Pressure Indicator Transmitter – This unit is essentially an electronicpressure gauge that generally reports to an ACC computer first, then to the PCCScomputer. In all plant processes a PIT usually reports to a PIC.

Front 14

PIC

Back 14

Pressure Indicator Controller - Using the readout from a PIT, you canusually control pressure in a particular piece of equipment using a PIC located ina Process Area’s ACC, or directly from the PCCS computer.

Front 15

HIC

Back 15

Hand Indicator Controller – These are local controllers located in eachACC that allow you to control a particular piece of machinery related to a plantprocess directly from its Area Control Center. These controllers usually relate tospeed on a pump, or percent open and closed on a valve.

Front 16

HIK

Back 16

Hand Indicator Control Station – These are manual switches located in anACC that allow you to turn a piece of equipment on or off from the ACC.

Front 17

PLC

Back 17

Programmable Logic Controller – PLCs have been installed as upgradesto the older controls in each ACC. Using these controllers you can set a processvariable (flow, level, etc.) and thereby automatically control a piece of equipmentremotely from the ACC. Field instrumentation reports first to the PLC, then to thePCCS computer.

Front 18

CSA

Back 18

Control Station Assembly - Toggle switches with their attendantcircuitry available in each ACC so that when the main computer fails, the lineOperator can take control of every major piece of equipment in that process areaand run it from the ACC.

Front 19

AGM Module

Back 19

Arizona Gear and Manufacturing – An electrical module thatconverts signal types

Front 20

Control Strategy

Back 20

The PCCS computer system uses information taken from fieldindicators and controllers and processes it into various Control Strategies thatautomate subsections of our plant.

Front 21

P & ID

Back 21

Process and Instrumentation Diagram – A drawing thatintegrates/overlays schematic representations of process equipment such as;piping, instruments, controls, analyzers, etc.