Industrial control motor overload protection

Copyright © 2009 Rockwell Automation, Inc. All rights reserved.

Industrial Power Control Systems :Motor Overload Protection

Theewin JidsathapornIC/SSC Business080-069-1222

Copyright © 2009 Rockwell Automation, Inc. All rights reserved. 2

First understand the workhorse of industry – The Motor• Over 10 million motors sold each year within the US accounting for over

60% of power consumption• The effect of a failed motor could result in the shutdown of a complete

process or manufacturing line resulting in significant cost impact to your business

• In a 10 year life cycle a motor could accumulateenergy costs 100 times its purchase value

• Energy usage by motors may besignificantly reduces by use ofan intelligent motor control solution

• It is estimated that in excess of $250 Billionis spent every year on excess maintenance activities mainly related to Motors


Motor Failures :Why do motors fail?

30%

19%14%

13%

10%

5%

9%

Overload

Contaminant

Single Phasing

Bearing Failure

Old Age

Rotor Failure

Other


Importance of Motor Protection

• A fundamental purpose for motor protection devices is to meet installation requirements of governing bodies (e.g. US National Electrical Code).


Importance of Motor Protection

• Another primary purpose is to protect investment of motor purchase cost.• Traditional overload relays allow production personnel to be reactive-only

when a condition occurs that results in the overload relay tripping. An overload trip means that the motor is stopped and production along with it – DOWNTIME!

• Many production facilities have quantified inmonetary terms what downtime costs them.

• They are analyzing the manufacturingprocess and are developing strategieswhere incremental improvements canbe made to maximize productivity.

What tripped? How did it trip? Was it preventable?Is anything else going to trip…when?


What Causes Motors to Fail?

• Excessive heat– Windings (impedance)– Directly proportional to load– Windings represent resistance – As current increases heat doubles as the square of the current– Heat is directly correlated to load– Loading is a function of load being driven & voltage– Bearings (friction)

• Excessive current– Moisture and contamination– Short circuit– Mechanical problems– Old age– Motor life can be reduced 50% if continuously overheated by only 10 degrees.


Causes of Motors to Fail?

• Excessive loads• Locked rotor (6 times FLC)• Low voltage (line losses)• Single phasing, phase failure• High inertial loads

Under Locked Rotor conditions, the motor can draw between 6 to 10 times the normal full load current (FLC). Excessive heat

will be generated by the windings !


• After the “Magic Smoke” Clears,”this Motor Winding is “Toast!”

Overcurrent Damage

• Damage caused by excessive current

New Motor Winding Motor Winding Damaged by Excessive Heat


Motor Life VS Heat Generation


IEC Bimetallic Overload Relay

• Ambient temperature compensated• Heat causes bimetal to deflect • Isolated alarm contact• Single phase sensitive• Manual / Automatic reset• Adjustment range 1.5:1• Phase loss sensitivity required• 15% setting accuracy

The Bulletin 193 bimetal overload relay offers all the features we expect

from a thermal overload relay.

Bulletin 193


IEC Bimetallic Overload Relay

Trip Indicator

Stop Button

Reset Button

Mechanical Connection to contactor

Electrical connections

Current setting Scale for motor nameplate current

Selector Automatic or Manual Reset

Trip contact 95/96 and signal contact 97/98

Terminals for motor leads (below)

Test operatorChanges state on Trip

and Signal contact

Used for testing of control wiring installation


Bimetal Overload Relay - Product Family

• 193-T1A….– Devices from 0.1 to 25A– Fits to 100-C09…23 Contactor

• 193-T1B….– Devices from 15 to 38A– Fits to 100-C30…37 Contactor

• 193-T1C….– Devices from 17 to 47A– Fits to 100-C43 Contactor

• 193-T1D…P– Devices from 35 to 90A– Panel Mount

• 193-T1D….– Devices from 35 to 90A– Fits to 100-C60…85 Contactor


Electronic Motor Protection

• The electronic motor protection range of products are the starting point of any Intelligent Motor Control solution offering simple through complex application solutions:– E1 Plus overload relays with add on

network modules for simple to medium applications

– E3 and E3 Plus overload relays for medium to advanced protection for more demanding applications

– Bulletin 825-P Modular Protection System for more advanced or demanding applications

Perform

ance

Bul 825-P

E3 and E3 Plus

E1 Plus


E1 Plus Electronic Overload Relay

Setting a new standard for electronic motor protection. The solid-state design provides accurate, reliable and repeatable protection. For simple to medium level applications.

The patented modular design allows for easy expansion of capabilities through side mount accessory modules, that can cost effectively be added to help enhance your machine operation & protection.



• DeviceNet Communication Module• Jam Protection Module including

Remote Reset • Remote Reset Module• PTC Thermistor Module• Ground Fault Module• Wide 5:1 adjustment rate• Current ranges from 0.1….800Amps



Over-molded power connections Latching

mechanism

• Self-Powered:• Rated current range: 0.1 .. 800A• Enhanced Protection

– Accurate Thermal overload – Ambient Sensitive– Responsive phase loss protection

• Flexible Adjustments:– Wide 5:1 FLA adjustment range– DIP switch settings (193/592-EE):

• Trip class: 10,15,20 or 30• Reset Mode: Manual or Auto

• Side module for DeviceNet communications (DSA)



Latching MechanismInsert MoldedPower Stabs

Reset ButtonTest Button

DIP Switches(193-EE, 592-EE only)

FLA Setting Dial

Mechanical Trip Actuator

Trip StatusIndicator

Control Terminals95 & 96 / 97 & 98

Load Terminations


E3 and E3 PlusElectronic Overload Relay

Offering a broad range of features in one complete, compact package to effectively manage and monitor motor performance in order to prevent and minimize production downtime. For medium to advanced protection requirements and demanding applications

• Built-in DeviceNet Communications• 0.4 . . . 5000A Current Ratings• Integrated I/O

– E3 : 2 input 1 output– E3 plus: 4 inputs 2 outputs



• Programmable protective functions(alarm level, trip level, time delay, and inhibit window)– Thermal Overload– Phase loss/imbalance (asymmetry)– Stall (High Overload during start)– Jam (High Overload during run)– Ground Fault (Plus version)– PTC thermistor inputs (Plus version)

• Data and Diagnostics– Motor Performance data– Device status– Network accessible


Enhanced ProtectionThermal Overload

• The E3/E3 Plus helps protect an electric motor from consuming more electric current than its nameplate rating which can be caused by:– Excessive load– Incorrectly sized motor– Low incoming voltage– Damaged equipment

• The trip class of the motor is selectable between 5 and 30– Trip class represents the maximum trip time in seconds when the motor

consumes 720% of the Full Load Amperes (FLA) rating of the electric motor

• %Thermal Capacity Utilization (%TCU) can be monitored to continuously view the thermal status of the electric motor


Enhanced ProtectionPhase Loss

• The E3/E3 Plus helps protect an electric motor when one phase of power is lost causing the remaining phases to consume more electric current

• Phase loss is typically caused by:– Blown fuse– Loose wire– Damaged contactor contacts

Phase loss is a leading cause of motor failure!


Enhanced ProtectionGround Fault

• The E3 Plus has the capability to monitor for short circuits or current leakage to ground and provide equipment level protection

• Low levels of ground fault current can rise very quickly causing damage to the electric motor if not caught early

It is important to catch ground faults at the leakage stage!


Enhanced ProtectionGround Fault

• The E3 Plus can monitor ground fault current for:– Solidly grounded systems

• Directly connected to ground– High resistance grounded systems

• Connected to ground through fixed impedance

• The E3 Plus offers two styles of the zero sequence method for detecting ground fault current:– Internal core balance current transformer detection of 1 to 5 Amps

(Cat. No. 193/592-EC2xx)– External core balance current transformer detection of 20 mA to 5 Amps

(Cat. No. 193/592-EC3xx)


Enhanced ProtectionJam, Stall and Underload

• The E3/E3 Plus helps provide these protection functions to ensure the safe operation of an electric motor or machine: – Jam protection

• Prevents an electric motor from running when a sudden rise in electrical current consumption occurs during its normal running operation

– Stall protection• Prevents an electric motor from running when an

extended amount of electrical current is consumed during its starting sequence

– Underload protection• Disables an electric motor when a sudden drop in

electrical current occurs indicating a possible mechanical malfunction


Enhanced ProtectionTemperature

• The E3/E3 Plus can help monitor the internal temperature of an electric motor by monitoring up to 6 Positive Temperature Coefficient (PTC) thermistors

• Thermistors can be embedded in an electrical motor to measure the actual temperature of the motor windings, rotor, and case

• Temperature protection is useful for preventing:– Blocked ventilation– High ambient temperatures– Excessive loads


Enhanced ProtectionCurrent Imbalance

• The E3/E3 Plus can help protect against the unequal consumption of electrical current on each of the three phases for an electric motor

• Current imbalance protection can be used to prevent electric motor damage from: – Imbalance in the voltage supply– Unequal motor winding impedance– Long and varying cable lengths


Motor Diagnostics

• The E3/E3 Plus Electronic Overload Relay not only helps protect your electric motor investment, but it can proactively assist in maintaining the electric motor by limiting:– Number of starts– Operating hours

• The E3/E3 Plus Electronic Overload Relay can also help provide diagnostic and metering information to help you understand the consumption patterns for the motor or process by providing: – RMS current– Percentage of full load current (%FLA)– Current imbalance– Thermal Capacity Utilization (%TCU)– Trip log– Warning log




E3 Plus with Voltage Protection & Energy Monitoring• The E3 Plus Electronic Overload Relay with Voltage Protection

and Energy Monitoring provides you with enhanced motor protection and motor energy consumption information– Enhanced Protection

• Current Protection• Voltage Protection• Power Protection

– Advanced Diagnostics• Voltage Metering• Energy Metering

– Additional Features• Trip History• Warning History• Snapshot Record• 6 Digital Inputs• E3 Status Object (Object Class 0x375)

NEW


Voltage Protection

• The E3 Plus with Voltage Protection and Energy Monitoring helps you to protect against the following voltage issues:– Under Voltage– Over Voltage– Phase Failure– Voltage Unbalance– Phase Rotation Mismatch– Under Frequency– Over Frequency

Protection on the Line Side of the Contactor


Power Protection

• To address power quality issues that could occur due to a specific application, the E3 Plus Electronic Overload Relay with Voltage Protection and Energy Monitoring also provides you with the following power based protection :– Real Power (kW) – Reactive Power (kVAR) – Apparent Power (kVA) – Power Factor (PF)

• Leading• Lagging


Energy Diagnostics

• To address energy usage concerns, the E3 Plus Electronic Overload Relay with Voltage Protection and Energy Monitoring provides you with the following energy diagnostic information:– Real Energy (kWh)– Reactive Energy (kVARh) – Apparent Energy (kVAh)– kW Demand– kVAR Demand– kVA Demand


Bulletin 825-PMotor Protection Relay

• Offering a broad range of features in one complete, compact package to effectively manage and monitor motor performance in order to prevent and minimize production downtime. For advanced and demanding protection requirements and applications

– Advanced protective functions– Suitable for Low and Medium Voltage applications– Warning settings – Expansion I/O cards– RTD Scanner module– Integrated I/O – Multiple Network communication options– Current ranges from 0.5….5000Amps


Bulletin 825-PMotor Protection Relay

• A-B Motor Protection Relay (MPR) with DeviceNet capability• Modular design• User programmable functions

– Overload– Underload– Thermal utilization– Ground Fault– Phase unbalance– Motor and ambient temperature– Start time monitor– Starts per hour limitations– Metering (V, I, Power, kWH)– RTD monitoring RTD


Comprehensive Protection


825P Application

C

MCCB

Machine #1 Machine #N

P.F. = 0.95Tx

Contactor

Branch Protection

System Protection

MCCB MCCB

Motor Protection

MCCB MCCB


825-P(Metering, Statistical and History)

Full Function MeteringSTATISTICAL VALUES• Elapsed time of operation• Stopped time• Percent of time running• Number of starts• Number of emergency starts• Date and time of last trip reset

VOLTAGE ELEMENTS• L-L Voltages• Ave L-L Voltages• L-N Voltages• Ave L-N Voltages• Voltage imbalance• System Frequency

CURRENT ELEMENTS• Phase current• Ave current• % motor Load• Current imbalance• Ground Fault Current• System Frequency

THERMAL ELEMENTS• % Thermal Capacity Utilization• RTD values

POWER ELEMENTS• Real Power (kW)• Reactive Power (kVAR)• Apparent Power (kVA)• Power Factor

ENERGY ELEMENTS• Real Energy (kWh)• Reactive Energy Forward (KVARh)• Reactive Energy Reverse (kVARh)• Apparent Energy (kVah)

HISTORICAL DATARecord of 5 most recent trip events with the following summary provided for each

• Event day and time• Trip identification• Phase and ground current values• Voltage values


Soft Start : SMC-3

Advantages• Up to 400HP @400VAc, 480A• Start ramp time selectable from 2 – 30 sec• Initial torque can be selected from 15% to 65%• Kick start can be selected to provide breakaway torque• Built in Overload protection• Diagnostics via flashing LED• Remote status via alarm contact• Ramp to stop

Limitations

• No field serviceable parts• Limited starting torque• 4 – 10 starts per hour


Soft Start : SMC-3

Frame 1 Frame 2 Frame 3 Frame 4 Frame 5

37A 85A 135A 251A 480A

3.95 in

5.55 in

1.75 in

1…37 A

5.1 in

8.2 in

2.8 in

43…85 A


Soft Start : SMC-3

• Line Ratings– Frame 1 (3 A, 9 A,16 A, 19 A, 25 A, 30 A, 37 A)– Frame 2 (43 A, 60 A, 85 A)– Frame 3 (108 A, 135 A)– Frame 4 (201 A, 251 A)– Frame 5 (317 A, 361 A, 480 A)

• Delta Ratings New Feature !!New Feature !!– 3 … 831 amps

• Two line voltage ratings– 200…480V or 200…600V @ 50/60 Hz

• Two control voltage ratings– 24V AC/DC or 100…240V AC

• 0…50°C Operating Temperature• Built in integral bypass and 3 phase control

1/L1 3/L2 5/L3

M

2/T1 4/T2 6/T3

10/T512/T6 8/T4

Line Connection

FLA Setting = FLA of Motor

1/L1 3/L2 5/L3

M3~

2/T1 4/T2 6/T312/T6 8/T4 10/T5

Delta Connection

FLA Setting = Motor FLA / 1.73

Bypass contactor

SCR – 3 phase control


Soft Start : SMC-3

• Built-in Motor Protection– Overload– Phase Reversal– Phase Loss/Open Load– Phase Imbalance

• Built-in SMC Protection– Over-temperature– Shorted SCR

• Advantage– Provides motor protection and minimizes the replacement costs

of the motor– Provides internal diagnostic to aid in troubleshooting– SMC turns off when any of these faults occur, and LED indicates fault condition

Fault indication - LED for indicationNumber of flashes for:

RUN/ONFAULT OFF


Soft Start : SMC-3

• Fewer system components (no external overload required)

• Meets applicable requirements as a motor overload protective device

• Less panel mounting space (mount vertical/horizontal without de-rating)

• Less wiring • Simplified maintenance• Compatible with motor protectors and IEC

contactors• Integrated bypass

– Minimize heat generation during run time– Bypass automatic closes when the motor reaches its

nominal speed. Resulting in a cooler-running component and reduction in enclosure size.


Soft Start : SMC-Flex

SMC-Flex

Advantages• Up to 1,000HP @ 400VAC, 1,250A• Programmable ramp time• Special pump control algorithm available• Preset slow speed capable• Can do full voltage start• Built in Electronic Overload protection• Diagnostics via local message display or comms• Remote status via alarm contacts or comms• Smart motor braking optional

Limitations• Limited starting torque



• Architecture Class SMC• High Feature/Functionality/Communications• Complete Range with Built-in SCR & Bypass contactor

(3 phase control)

– Minimizes heat dissipation– Optimizes enclosure sizing

• Starting & Stopping mode– Soft Start (with Selectable Kickstart)– Soft Stop– Current Limit Start (with Selectable Kickstart)– Full Voltage– Preset Slow Speed – Linear Speed Acceleration(with Selectable Kickstart)– Dual Ramp (with Selectable Kickstart)– Pump control (optional)– Braking (optional)

Frame 1/2 Frame 3 Frame 4 Frame 5 Frame 6 Frame 7

85A 135A 251A 480A 780A 1250A

1/L1 3/L2 5/L3

M

2/T1 4/T2 6/T3

10/T512/T6 8/T4

Line Connection

FLA Setting = FLA of Motor

1/L1 3/L2 5/L3

M3~

2/T1 4/T2 6/T312/T6 8/T4 10/T5

Delta Connection

FLA Setting = Motor FLA / 1.73



• Line Ratings (16 current ranges)– Frame 1 & 2 – (5, 25, 43, 60, 85)– Frame 3 – (108, 135)– Frame 4 – (201, 251)– Frame 5 – (317, 361, 480)– Frame 6 – (625 A, 780 A)– Frame 7 – (970 A, 1250 A)

• Delta Ratings– 8…1600 Amps

• Two Voltage Ratings– 200 - 480V or 200 - 600V @ 50/60 Hz

• Control Voltage Ratings– 100-240 VAC or 24V AC/DC

• 0 - 50° C Operating Temperature



• Electronic Motor Overload Protection with selectable Trip Classes (Class 10, 15, 20, 30 or Off)

• Stall Detection• Jam Detection • Ground Fault Protection• Thermistor Input (PTC)• Diagnostics and

Warnings • Monitoring• Configurable Auxiliary

Contacts

• Over Temperature• Stall Detection• Open SCR Gate• Shorted SCR Gate• Overload • Underload• Excessive Starts/Hour• Thermistor (PTC)• Current Unbalance• Line Fault• Power Loss• Voltage Unbalance• Phase Reversal• Under/Overvoltage• Jam Detection• Communication Fault• Ground Fault• Anti-Backspin Timer

• Alarm Settings Can Be Programmed for:

– Thermal Overload– Ground Fault– Jam – Underload– Over Voltage– Under Voltage

• Alarm Settings Can Be Used to Provide Advance Notification of Impending Trips

• Three-phase currents• Three-phase voltages• Power in kW• Power usage in kWH• Motor thermal capacity

usage• Power factor of the

running motor• Elapsed time of motor

operation

Protection Fault Diagnostics Fault Alarms Monitoring



• Interfaces to DPI communication modules– Remote I/O– RS 485-DF1 – DeviceNet™– ControlNet– EtherNet– ProfiBUS– Lonworks– Interbus

ControlNetDeviceNetRemote I/O

Module Installation Installation Complete

Using the SMC-Flex controller, you can accessParameter settingsFault DiagnosticsMeteringRemote start-stop control

Consistency in Communications – SMC & Drives

Copyright © 2009 Rockwell Automation, Inc. All rights reserved.

THANK YOU

Theewin JidsathapornIC/SSC Business080-069-1222

www.ab.comwww.rockwellautomation.com

Technology

Industrial control motor overload protection