PLC
Troubleshooting
& Maintenance
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Manual Work
Brain

Motion

Senses

Human Lags:
• Cannot Work 24 Hours
• Cannot work with 100% Accuracy &
precision
• Efficiency decreases as energy
decreases

Energy

Human
Automatic Work

Controllers

Actuators
Sensors

Machine
Advantages:

• Accuracy
• No idle Time
• More Production

Energy

Lags:

• Regular
Troubleshooting &
Maintenance
What is Controllers?
Controller is a part of Automatic Control System, which process the
signal from sensors & send it to the actuators

Sensors

Controller

A closed Loop Control System

Actuator
This is a PLC

Input Terminals

Output Terminals
D/A Card
Programming Cable
A/D Card
RS 485
This is a PLC

Power 24 VDC

Battery
Input Terminals

Programming Cable

Output Terminals
This is a PLC

Input Terminals

Programming Cable

Output Terminals

Power 24 VDC
Understanding PLC
Understanding PLC
How to Select a PLC?
Step 1:
Selecting the Inputs
- Number of Inputs
- Input Types – NPN or PNP
- Nature of Inputs– Digital or
Analog
- Voltage rating of the
Inputs
Step 2:

Step 3:

Selecting the Outputs
- Number of Outputs
- Nature of Outputs – Digital
or Analog
- Voltage rating of the Inputs

Length of Program – Big or Small
Nature of Program – Ladder
Logic, SFC, Instruction List, FDB
Programming Languages
Ladder Logic
SFC

Instruction List
FDB
PLC Ladder Logic
Common Industrial Hardware
Representing the Binary Concept
Basics of
Machine
Language
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Basics of Machine Language

Bits – Nibble - Byte –Word
 Unlike

English, computers have only two
characters available  1 or 0.
 Each 1 or 0 is called a binary digit or bit.
 Binary is base or radix 2
PLC

Inputs & Outputs
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Digital Inputs & Outputs
Typical Digital Input/ Output Signals
•
•
•
•

12 VDC
24 VDC
120 VAC
240 VAC
Analog Inputs






Typical analog
signals come from
temperature,
pressure, position,
and motor speed.
Analog input
modules convert
analog signals to
digital words.
Analog input
signals are current
or voltage.

PLC INPUTS & OUTPUTS

Typical Analog input signals
0 to 10 volts DC
-10 to +10 volts DC
0 to 5 or 1 to 5 volts DC
4 to 20 milliamps
0 to 20 milliamps
-20 to +20 milliamps
PLC INPUTS & OUTPUTS

Connections from Field Devices

Image courtesy of Allen-Bradley, a Rockwell Automation business
PLC INPUTS & OUTPUTS

Differential Analog Input Connections

Image courtesy of Allen-Bradley, a Rockwell Automation business
Analog Outputs





PLC INPUTS & OUTPUTS

Typical analog signals are required
by Servo Valves, VFD’s, Servo Motors,
Meters
Analog Output modules convert
Digital bits to analog signal.
Analog Output signals are current or
voltage.

Typical Analog Output signals

0 to 10 volts DC
-10 to +10 volts DC
0 to 5 or 1 to 5 volts DC
4 to 20 milliamps
0 to 20 milliamps
-20 to +20 milliamps
Basics of PLC
Programming
Ladder Logic
PLC Enclosure
& System
Components
NEMA – 12
National Electric Manufacturer
Association, USA
PLC Enclosure

Prevents:
Dust
Water
Oil
Mostly used for
Indoor applications of automation. Some examples
are
Packaging
Material handling
Non-corrosive process control.
NEMA enclosures are available in sizes from small wall
mounts to multi-door freestanding models.
Enclosure Layout
Placement of PLC Components

To allow
maximum cooling

All Controller components
should be mounted in a vertical
(upright) position.
Duck & Wire Layout
Keep AC signals separate from DC Signals
DC Signals I/O lines, such as TTL and analog
AC Signals Incoming Line Wires

Minimizes the possibility
of electrical noise pickup.
Power
Requirement &
Safety Circuitry
POWER REQUIREMENTS
Typical Power Requirement
220 VAC
SAFETY CIRCUITRY
Door Switch

Pull Rope Switch

Emergency Switch

Automation Studio
Master or Safety Control
Relays

Automation Studio
PLC FAULT CONTACT
PROTECTION

Automation Studio
PLC
Maintenance
HEAT, DUST & NOISE
REGULATION
PLC MAINTENANCE
HEAT & DUST REGULATION

Temperature Withstand Range

0 ~ 60°C
PLC MAINTENANCE

NOISE REGULATION

Shielded Cables for better communication
PLC MAINTENANCE

NOISE GENERATING DEVICES

MOTOR STARTERS

SOLENOIDS

RELAYS AND CONTACTORS

VARIABLE FREQUENCY DRIVES
PLC TROUBLESHOOTING 2

NOISE FROM GROUNDING
PLC
I/O Installation,
Wiring & Precautions
I/O INSTALLATION, WIRING, AND
PRECAUTIONS

I/O MODULE INSTALLATION
Placement and installation of the I/O modules is simply a
matter of inserting the correct modules in their proper
locations. This procedure involves verifying the type of
module (220 VAC/ 24 VDC output, 220 VDC/ 24 VDC
input, etc.) and the slot address as defined by the I/O
address assignment document. Each terminal in the
module is then wired to the field devices that have
been assigned to that termination address. The user
should remove power to the modules (or rack) before
installing and wiring any module.11
I/O INSTALLATION, WIRING, AND
PRECAUTIONS

WIRE SIZE CONSIDERATION
WIRING
I/O INSTALLATION, WIRING, AND
PRECAUTIONS

WIRE SIZE CONSIDERATION
WIRE LABELLING

I/O INSTALLATION, WIRING, AND
PRECAUTIONS
I/O INSTALLATION, WIRING, AND
PRECAUTIONS

WIRE BUNDLING
PLC
START-UP & CHECKING
PROCEDURES
PLC START-UP AND
CHECKING PROCEDURES

Model numbers
Placement

Power Supply
Inspection

Verify Field Wiring
&
I/O comm. cables
STATIC INPUT/ OUTPUT WIRING
CHECK

Input Terminals

Output Terminals
PLC
PREVENTIVE
MAINTENANCE
PLC
PREVENTIVE MAINTENANCE
Regular Filter Cleaning

Regular Dusting
Dust restricts heat dissipation
Avoid Conductive Dust
I/O Module Check for any
Loose connections

Avoid Noise generating
Equipment close to PLC

Avoid documentation to create
HOT SPOT

Install vibration Detector in
area of high vibration
PLC
PREVENTIVE MAINTENANCE
PLC
TROBLESHOOTING
AREAS
POWER LED IS TURNED OFF

Is Power Indicator Lit?

NO

Is power supply
operating?

Supply the power

NO

YES
NO

Is the voltage within
the rated power?

Is the fuse
blown?

Does the power
LED turned on?

YES

NO

NO

YES

Does the power
LED turned on?

YES
Does the power
LED turned on?

Eliminate excess current &
switch power ON/OFF

NO
Write the steps &
Contact customer care

YES

Connect the power supply properly

NO

YES

Over current
Device activated?

YES

Replace the Fuse

NO
Is the power
Supply cable Connected?

YES

See the power supply within
180 ~ 240 VAC

NO

YES

Does the power
LED turned on?

NO

Does the power
LED turned on?

YES

COMPLETE
RUN Indicator not Lit

RUN INDICATOR NOT LIT

NO

YES
Is the ERR/ALM
Indicator Lit?

Is PC mode
Displayed on Programming
Device?

YES

NO

Determine the cause of the
error with the Programming
device

Is PC mode displayed
On Programming device?

NO

Turn the power supply
OFF & then ON again

YES

Is a fatal error
Displayed?

YES

Identify the error, eliminate
its cause, & clear the error.

NO
Switch to RUN or
MONITOR mode

Is the RUN
Indicator lit?

YES
END

NO

Replace the
CPU Unit

FATAL ERROR
CHECK
Program cannot be written
PROGRAM CANNOT BE WRITTEN TO PLC

Is the mode setting
Switch set to the remote
stop?

NO

Switch to the remote STOP
mode & execute the
program mode

YES

NO

Is ERR LED Blinking?

NO

COMPLETE

After reading error code by
using peripheral device,
correct the content
Environment Condition Check

Is the ambient
temperature below 55
degree?

NO

ENVIRONMENT CONDITION CHECK

Consider using a FAN or
COLLER

YES
Is the ambient
temperature above
0 degree?

NO
Consider using a HEATER

YES
Is the ambient humidity
between 10% ~ 85%

NO

Consider using an air
conditioner

YES
NO
Is noise being controlled?

Install surge protectors or other
noise reducing equipment at
noise sources

YES
NO
Is the installation
environment ok?

YES

END

Consider constructing an
instrument panel or cabinet
ERR/ALM INDICATOR FLASHING

ERR/ALM Indicator flashing
Determine the cause of
the error with a
programming device

IS a non fatal error
Indicated?

YES

Identify the error, eliminates its
cause & clear the error

NO

Is the ERR/ALM
Indicator flashing?

FLASHING

NO

Replace the
CPU Unit

END

NON- FATAL ERROR
CHECK
0002

MALFUNCTIONING OF SOL 1

0003
01003

SOL 1

I/O CHECK

01003

NO

Is the IR 01003 output
Indicator operating?

YES
Wire correctly

Operation ok?

Correct the short circuit or
limit the connected load
to the specified range

NO
NO

Monitor the ON/OFF
status of IR 01003
with the
Programming
Device

Is the Output wiring
correct?
YES

YES

Is the external power
supply Shorted or
overload?

YES

Operation ok?
YES

NO
Disconnect the external
wires & check the
conductivity of each wire

YES

Check output
device SOL 1.

Operation ok?

NO

Replace the CPU Unit,
Expansion Unit, or Expansion
I/O Unit with the problem

NO

Next slide

Check the voltage at IR
01003 terminals
0002

0003
01003

SOL 1

I/O CHECK

From previous slide

01003

Are the IR 0002 & IR 0003
Input indicators operating
Normally?

NO

Check the voltage at the
IR 0002 & IR 0003 terminals

YES
Check the voltage at the
IR 0002 & IR 0003 terminals

Operation ok?

Operation ok?
YES

NO

NO
YES

Check operation by using
a dummy input signal to
turn the input ON & OFF

YES

Is the wiring correct?

YES

Are the terminals
screws loose?
NO

NO
Wire Correctly

Tighten the
terminal screws

NO
Operation ok?

Replace the CPU Unit,
Expansion Unit, or
Expansion I/O Unit
with the problem

Check input
devices LS1 & LS2

Return to Start

Replace the CPU Unit,
Expansion Unit, or Expansion
I/O Unit with the problem
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presents

PLC – Programmable Logic Controller
Delta DVP 14 SS + 16 SP
• 100+ PLC Video Tutorials
Allen Bradley M1000
• Doubt Clearing Complementary LIVE Sessions on Team Viewer
Siemens S7 200
• Ladder Logic Programming
Schneider
• PLC Presentations, PLC Circuits, PLC Codes
Analog Cards Programming
• FREE PLC Simulation Software for Practice
04 AD – Analog to Digital
04DA- Digital to Analog
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Course

4 PLC’s Training
Platforms

$149
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• FREE Circuits Diagram

For more courses visit www.nfiautomation.org
Thanks
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PLC Troubleshooting & Maintenance

  • 1.
  • 2.
    Manual Work Brain Motion Senses Human Lags: •Cannot Work 24 Hours • Cannot work with 100% Accuracy & precision • Efficiency decreases as energy decreases Energy Human
  • 3.
    Automatic Work Controllers Actuators Sensors Machine Advantages: • Accuracy •No idle Time • More Production Energy Lags: • Regular Troubleshooting & Maintenance
  • 4.
    What is Controllers? Controlleris a part of Automatic Control System, which process the signal from sensors & send it to the actuators Sensors Controller A closed Loop Control System Actuator
  • 5.
    This is aPLC Input Terminals Output Terminals D/A Card Programming Cable A/D Card RS 485
  • 6.
    This is aPLC Power 24 VDC Battery Input Terminals Programming Cable Output Terminals
  • 7.
    This is aPLC Input Terminals Programming Cable Output Terminals Power 24 VDC
  • 8.
  • 9.
  • 10.
    How to Selecta PLC? Step 1: Selecting the Inputs - Number of Inputs - Input Types – NPN or PNP - Nature of Inputs– Digital or Analog - Voltage rating of the Inputs Step 2: Step 3: Selecting the Outputs - Number of Outputs - Nature of Outputs – Digital or Analog - Voltage rating of the Inputs Length of Program – Big or Small Nature of Program – Ladder Logic, SFC, Instruction List, FDB
  • 11.
  • 12.
  • 13.
  • 14.
  • 15.
    Basics of MachineLanguage Bits – Nibble - Byte –Word  Unlike English, computers have only two characters available  1 or 0.  Each 1 or 0 is called a binary digit or bit.  Binary is base or radix 2
  • 16.
  • 17.
    Digital Inputs &Outputs Typical Digital Input/ Output Signals • • • • 12 VDC 24 VDC 120 VAC 240 VAC
  • 18.
    Analog Inputs    Typical analog signalscome from temperature, pressure, position, and motor speed. Analog input modules convert analog signals to digital words. Analog input signals are current or voltage. PLC INPUTS & OUTPUTS Typical Analog input signals 0 to 10 volts DC -10 to +10 volts DC 0 to 5 or 1 to 5 volts DC 4 to 20 milliamps 0 to 20 milliamps -20 to +20 milliamps
  • 19.
    PLC INPUTS &OUTPUTS Connections from Field Devices Image courtesy of Allen-Bradley, a Rockwell Automation business
  • 20.
    PLC INPUTS &OUTPUTS Differential Analog Input Connections Image courtesy of Allen-Bradley, a Rockwell Automation business
  • 21.
    Analog Outputs    PLC INPUTS& OUTPUTS Typical analog signals are required by Servo Valves, VFD’s, Servo Motors, Meters Analog Output modules convert Digital bits to analog signal. Analog Output signals are current or voltage. Typical Analog Output signals 0 to 10 volts DC -10 to +10 volts DC 0 to 5 or 1 to 5 volts DC 4 to 20 milliamps 0 to 20 milliamps -20 to +20 milliamps
  • 22.
  • 23.
    PLC Enclosure & System Components NEMA– 12 National Electric Manufacturer Association, USA
  • 24.
    PLC Enclosure Prevents: Dust Water Oil Mostly usedfor Indoor applications of automation. Some examples are Packaging Material handling Non-corrosive process control. NEMA enclosures are available in sizes from small wall mounts to multi-door freestanding models.
  • 25.
  • 26.
    Placement of PLCComponents To allow maximum cooling All Controller components should be mounted in a vertical (upright) position.
  • 27.
    Duck & WireLayout Keep AC signals separate from DC Signals DC Signals I/O lines, such as TTL and analog AC Signals Incoming Line Wires Minimizes the possibility of electrical noise pickup.
  • 28.
  • 29.
  • 30.
    SAFETY CIRCUITRY Door Switch PullRope Switch Emergency Switch Automation Studio
  • 31.
    Master or SafetyControl Relays Automation Studio
  • 32.
  • 33.
  • 34.
    PLC MAINTENANCE HEAT &DUST REGULATION Temperature Withstand Range 0 ~ 60°C
  • 35.
    PLC MAINTENANCE NOISE REGULATION ShieldedCables for better communication
  • 36.
    PLC MAINTENANCE NOISE GENERATINGDEVICES MOTOR STARTERS SOLENOIDS RELAYS AND CONTACTORS VARIABLE FREQUENCY DRIVES
  • 37.
  • 38.
  • 39.
    I/O INSTALLATION, WIRING,AND PRECAUTIONS I/O MODULE INSTALLATION Placement and installation of the I/O modules is simply a matter of inserting the correct modules in their proper locations. This procedure involves verifying the type of module (220 VAC/ 24 VDC output, 220 VDC/ 24 VDC input, etc.) and the slot address as defined by the I/O address assignment document. Each terminal in the module is then wired to the field devices that have been assigned to that termination address. The user should remove power to the modules (or rack) before installing and wiring any module.11
  • 40.
    I/O INSTALLATION, WIRING,AND PRECAUTIONS WIRE SIZE CONSIDERATION WIRING
  • 41.
    I/O INSTALLATION, WIRING,AND PRECAUTIONS WIRE SIZE CONSIDERATION
  • 42.
    WIRE LABELLING I/O INSTALLATION,WIRING, AND PRECAUTIONS
  • 43.
    I/O INSTALLATION, WIRING,AND PRECAUTIONS WIRE BUNDLING
  • 44.
  • 45.
    PLC START-UP AND CHECKINGPROCEDURES Model numbers Placement Power Supply Inspection Verify Field Wiring & I/O comm. cables
  • 46.
    STATIC INPUT/ OUTPUTWIRING CHECK Input Terminals Output Terminals
  • 47.
  • 48.
    PLC PREVENTIVE MAINTENANCE Regular FilterCleaning Regular Dusting Dust restricts heat dissipation Avoid Conductive Dust I/O Module Check for any Loose connections Avoid Noise generating Equipment close to PLC Avoid documentation to create HOT SPOT Install vibration Detector in area of high vibration
  • 49.
  • 50.
  • 51.
    POWER LED ISTURNED OFF Is Power Indicator Lit? NO Is power supply operating? Supply the power NO YES NO Is the voltage within the rated power? Is the fuse blown? Does the power LED turned on? YES NO NO YES Does the power LED turned on? YES Does the power LED turned on? Eliminate excess current & switch power ON/OFF NO Write the steps & Contact customer care YES Connect the power supply properly NO YES Over current Device activated? YES Replace the Fuse NO Is the power Supply cable Connected? YES See the power supply within 180 ~ 240 VAC NO YES Does the power LED turned on? NO Does the power LED turned on? YES COMPLETE
  • 52.
    RUN Indicator notLit RUN INDICATOR NOT LIT NO YES Is the ERR/ALM Indicator Lit? Is PC mode Displayed on Programming Device? YES NO Determine the cause of the error with the Programming device Is PC mode displayed On Programming device? NO Turn the power supply OFF & then ON again YES Is a fatal error Displayed? YES Identify the error, eliminate its cause, & clear the error. NO Switch to RUN or MONITOR mode Is the RUN Indicator lit? YES END NO Replace the CPU Unit FATAL ERROR CHECK
  • 53.
    Program cannot bewritten PROGRAM CANNOT BE WRITTEN TO PLC Is the mode setting Switch set to the remote stop? NO Switch to the remote STOP mode & execute the program mode YES NO Is ERR LED Blinking? NO COMPLETE After reading error code by using peripheral device, correct the content
  • 54.
    Environment Condition Check Isthe ambient temperature below 55 degree? NO ENVIRONMENT CONDITION CHECK Consider using a FAN or COLLER YES Is the ambient temperature above 0 degree? NO Consider using a HEATER YES Is the ambient humidity between 10% ~ 85% NO Consider using an air conditioner YES NO Is noise being controlled? Install surge protectors or other noise reducing equipment at noise sources YES NO Is the installation environment ok? YES END Consider constructing an instrument panel or cabinet
  • 55.
    ERR/ALM INDICATOR FLASHING ERR/ALMIndicator flashing Determine the cause of the error with a programming device IS a non fatal error Indicated? YES Identify the error, eliminates its cause & clear the error NO Is the ERR/ALM Indicator flashing? FLASHING NO Replace the CPU Unit END NON- FATAL ERROR CHECK
  • 56.
    0002 MALFUNCTIONING OF SOL1 0003 01003 SOL 1 I/O CHECK 01003 NO Is the IR 01003 output Indicator operating? YES Wire correctly Operation ok? Correct the short circuit or limit the connected load to the specified range NO NO Monitor the ON/OFF status of IR 01003 with the Programming Device Is the Output wiring correct? YES YES Is the external power supply Shorted or overload? YES Operation ok? YES NO Disconnect the external wires & check the conductivity of each wire YES Check output device SOL 1. Operation ok? NO Replace the CPU Unit, Expansion Unit, or Expansion I/O Unit with the problem NO Next slide Check the voltage at IR 01003 terminals
  • 57.
    0002 0003 01003 SOL 1 I/O CHECK Fromprevious slide 01003 Are the IR 0002 & IR 0003 Input indicators operating Normally? NO Check the voltage at the IR 0002 & IR 0003 terminals YES Check the voltage at the IR 0002 & IR 0003 terminals Operation ok? Operation ok? YES NO NO YES Check operation by using a dummy input signal to turn the input ON & OFF YES Is the wiring correct? YES Are the terminals screws loose? NO NO Wire Correctly Tighten the terminal screws NO Operation ok? Replace the CPU Unit, Expansion Unit, or Expansion I/O Unit with the problem Check input devices LS1 & LS2 Return to Start Replace the CPU Unit, Expansion Unit, or Expansion I/O Unit with the problem
  • 58.
    100+ Video Tutorials CouponCode in $99 $49 https://www.udemy.com/nfi-plc-online-leaning/?couponCode=slideshare Life time Access Course Outline Learn to Code | Code to Learn nfi Learn 4 PLC’s in a Day presents PLC – Programmable Logic Controller Delta DVP 14 SS + 16 SP • 100+ PLC Video Tutorials Allen Bradley M1000 • Doubt Clearing Complementary LIVE Sessions on Team Viewer Siemens S7 200 • Ladder Logic Programming Schneider • PLC Presentations, PLC Circuits, PLC Codes Analog Cards Programming • FREE PLC Simulation Software for Practice 04 AD – Analog to Digital 04DA- Digital to Analog For more courses visit www.nfiautomation.org
  • 59.
    PLC & VFDAdvanced Course 4 PLC’s Training Platforms $149 Course Link: Course Highlights: http://www.wiziq.com/course/28882-plc-andac-drives-online-certificate-trainaing-course • 30 Live Practical Classes on PLC, Analog Cards & AC drives- VFD • 100+ PLC Video Tutorials with Lifetime Access & FREE PLC Simulator • FREE Circuits Diagram For more courses visit www.nfiautomation.org
  • 60.