plc in automation

8/10/2019 PLC IN AUTOMATION

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Application of PLCsin Automation


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Outline of Departments in BHELBlock 1 Hydro Generator Engineering (HGE)

Block 2 Electrical Machines Group

Block 3 Transformer Engineering Division(TRE)

Block 4 Switchgear, Control gear and Rectifier (SCR)

Block 5 Foundry Shop

Block6 Coil Insulation & Manufacturing(CIM)

Block 7 Gas Plant

Block 8 Tool & Gauge Manufacturing(TGM)

Block 9 Traction Alternator Manufacturing(TAM)

Block 10 Casting and Press Shop


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EMX Department (ElectronicsMaintenance)

oBreakdown maintenance of machines

oRetrofitting / renovation and up gradation of old & obsolete controlsstate-of-the art systems.

oIn-house repair & testing of CNC controllers, drives, PLCs, and othelectronic items

oProgramming of PLC & CNC controllers.

oFraming specifications, technical reviews, involvement during E&Cprojects for Electronics / CNC based machines, plants and equipme


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EMX Department (ElectronicsMaintenance)oElectrically controlled machinery replaced by automated systems

oBHEL has a vast array of such machines around 330 of them.

oThe department is deputed for maintenance of such control paneand CNCs.

oA detailed study of these panels was done during the training prooDemo modules for control panels and PLCs were worked upon dschedule.


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WHATIS CNC RETROFITTING?

OBJECTIVES

o Cost- effective modernization.

o Large size & costlier ageing machine tools need not be discarded.

FACTORS FOR SELECTION

o Geometric accuracy.

o Sound mechanical condition.

o Availability of space on the machine.

o Up gradation of obsolete CNC system.


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ADDITION OF FEATURE / FACILITIES

o Complete reconditioning of the machine .

o

State of the art CNC control system with PLC.o AC/DC Digital/Analog servo feed drives for individual axes and S

o Linear/ Rotary position feedback systems.

o Automatic Tool Turrets/Changers.

o Hydraulic Power Packs ,Chucks & Tail-stock.

o Automatic Centralized lubrication system & Coolant with PLC.


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ADVANTAGES OF CNC RETROFITTING

a new lease of life to the machine tools through

cost effective modernization

capability enhancementaddition of facilities

restoration of accuracies

quality improvement

better accuracy

productivity enhancement by 100-200% by

cycle time reduction

reduction in rework / rejection

reduction in down time


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CNC (Computerized NumericalController)oProvide control information used to produceparts.

oCNC controllers range in capability fromsimple point-to-point linear control to highlycomplex algorithms that involve multiple axescontrol.

oCNC controllers configured to control greaterthan six axes


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CNC MACHINE TOOL (CLOSED LOOP SYSTEM)

SERVO

DRIVE

SERVO

MOTOR

S

P

I

N

D

L

E

TABLE

D N C LINK

TAPE READER

OTHER DEVICES

MACHINE ELEME

DISPLAY UNIT

INPUT/OUTPUT

KEYBOARD

FLOPPY DISC / CD

BALL

SCREW

JOB

TACHO / POSITION

SENSOR

VELOCITY

FEEDBACK

POSITIONAL FEEDBACK

PLC NC

CNC

I / P

O /P


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PLC(Programmable LogicController)

oIts an Industrial microcontroller system.oProgrammed at Industrial site rather thancomputer programmers.

oBlock schematic is shown :


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How they are different frommicrocontrollers:

oSpecial Input / Output arrangement usingmodules .

oProgram memory is limited inmicrocontrollers.

oProgramming language interoperability.

PLC(Programmable LogicController)


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Agenda

Project Description

oIt showcases the fundamental use of Programmable Logic Controllers iAutomation integrated with Computerized Numerical Control Machines.

Project Methodology

oThe Siemens PLC is used as primary controlling element in the automalubrication system in CNC machines

Key Findings/Results

oManual lubrication has many pitfalls.

oPLC incorporated in machine is more efficient in terms of SAFETY & RE

Conclusion

oPLCs provide flexible, error correctable, low cost solution to automation


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Project Description

Objectiveo Control of lubrication systems in CNC machines using SIEMENS PLCSIMA

300.

o It comprise of following main components : Controller , Pump & Reservoir, SMetering Valves, feed Lines .

o Control of following parameters is achieved :o On/Off switching

o Oil level in tanko Oil pressure in pipes

o Oil flow rate in pipes

o Overload protection of pump & relays

o Emergency condition


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Schematic Diagramof Automated OilLubrication System


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Procedure/MethodologyProcedure:

oPLC programming for process control .

oProgram is stored into user memory.

oCPU sequentially reads instructions & operate control.

oProgram can be written in 3 basic formats :o STL(Statement List)

o SCF(Sequential Function chart)

o LAD(Ladder Logic)- Most usedo ST(Structured Test )

o IL(Instruction List)
http://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20fbd.pdf


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Key Assumptions:

oThe Oil lubrication is Set On for 30s and off or 5s assuming the fo

conditions are met:-o Emergency button is not ON.

o Overload relay is at correct switching position

o Control button is ON

o Oil level is adequate in tank

o Oil pressure is above 6 bar.

o Oil flow rate is above

Procedure/Methodology


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PROGRAM : LADDER LOGICProgramming language: STEP 7Software: Simatic Manager

Assume the following:IX.Y-INPUTMX.Y-MEMORY BITQX.Y-OUTPUTONDT-ON DELAY TIMEROFDT-OFF DELAY TIMERTV-TIMER VALUE AS #SSTI0.0-Emergency button M0I0.1-Control button (Push) Q0.1- Contactor ON M0.3, M

I0.2-Start mem.bitI0.3-StopI0.4-Overload relayI0.5-Float switchI0.6-Flow meterI0.7-Pressure switchI1.0-Contacator i/p

LOGO!Soft Comfort - lubrication logic lad.pdf
http://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdfhttp://localhost/var/www/apps/conversion/tmp/scratch_5/LOGO!Soft%20Comfort%20%20-%20lubrication%20logic%20lad.pdf


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Data

observ


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Data

Observ54 percent of

are contribute

lubrication or

Too little lu

much lubricat

often enough

life significant


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Project Summary


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Manual Lubrication

oLoss of production due to downtime

oLabor for repair

oReplacement bearings and related materials

oProduction labor cost

oMissed customer deliveriesoIncreased safety issues when repairing machinery


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Automated LubricationoIntegrated the reservoir, controller and fault monitor capability in one usimplicity installation cost reduction.

oDuring a lubrication cycle, the pump delivers lubricant through a supplymetering devices.

oA lubrication cycle can be initiated by a PLC

oMonitor for proper system operation, blocked line detection and low-re

oAlarm signals can be connected to a PLC, light or horn for remote notif

plc in automation

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