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Motor Protection for this Millennium. Presented by John S. Levine, P.E. Levine Lectronics and Lectric, Inc. John@L-3.com. Facts:. Computers and the Internet are here to stay! With microprocessors it is just as easy to give you everything verses several relays to do a job!
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Motor Protection for this Millennium Presented by John S. Levine, P.E. Levine Lectronics and Lectric, Inc. John@L-3.com
Facts: • Computers and the Internet are here to stay! • With microprocessors it is just as easy to give you everything verses several relays to do a job! • Corporations are downsizing personnel! • We are in a constant state of change!
Conclusions: • The equipment has to be able to help the few remaining personnel solve the problems even if that person is 1000 miles away ! • Products need to be designed as families to reduce the cost. • Products are much more complex than 10 years ago! • We can not avoid the change!
Motor Failure Rates and Cost • Motor failure rate is conservatively estimated as 3-5% per year. • In Mining, Pulp and Paper industry motor failure rate is up to 12%. • Motor failure cost contributors: • Repair or Replacement. • Removal and Installation. • Loss of Production.
469 and 369 Motor Management Relay Protection and management of medium voltage motors and driven equipment
Product Highlights • Inputs / Outputs • Motor Protection • Power Metering • Diagnostics • Communications / 469PC/369PC • Simulation
Product Highlights • Comprehensive motor protection • Protection of motors with high inertia loads • Induction and Synchronous motors • Two speed motors • Differential protection (469), Input to 369 • Reduced voltage start • RTU functions • Remote start/stop
CT and VT Inputs Typical wiring • 3 phase CTs • 1 amp • 5 amp • 3 differential CTs (469) • 1 ground CT • Zero sequence • Residual • 3 phase VTs • Open Delta • Wye • Core balance differential CTs • 1 amp • 5 amp
CT Inputs Residual ground wiring Alternate differential wiring • Summation of two CTs • provides a larger zone of protection • Observe polarity
Using Power Factor Correction Capacitors CT’S Contactor Cap
RTD Inputs RTD wiring • 12 RTDs, field programmable type • Independent trip and alarm settings • Trip voting • Feedback to thermal model • Programmable RTD name • Open sensor detection
Digital Inputs • 9 digital inputs (469), 6 digital inputs (369) • pre-defined (Access, test-469, emergency, remote reset, starter status-469) • 4 assignable (speed switch, load shed, pressure, vibration, tachometer, counter, general & programmable)
Analog Inputs (469) Loop powered analog inputs • 4 analog inputs (469) • self powered or • loop powered • 100 mA @ 24 Vdc • Assignable name • Min., max., & units • Block from start • Trip • Alarm • delay
Output Relays • 6 output relays (469), 4 output relays (369), • Form C, • 4 programmable analog outputs(469), option on 369 • 4-20 or 0-1 mA (as ordered-469) programmable on 369 • 29 programmable parameters • 2 RS485 ports(469), 3 RS485 ports(369), • 1 front panel RS232 port • 22 front panel status indicators (469), 10 on 369
Motor Protection Single line diagram • Thermal • Block starts • Short circuit / backup • Mechanical jam • Phase reversal • Unbalance • Undercurrent • Ground fault / backup • Differential • Acceleration • Stator/Bearing/Other • Ambient RTD
Thermal Model - Thermal Capacity Used We will use the following model to aid in a better understanding of motor thermal modeling concepts. The motor’s thermal capacity, that is to say, the amount of heat energy the motor can hold, will be represented by the glass vessel. The lava like fluid filling the vessel will represent thermal energy or heat energy that has been absorbed by the motor.
Thermal Model - Thermal Capacity Used • The sources of thermal energy that will fill the vessel or heating the motor are: • Ambient temperature • Motor losses due to current unbalances and I squared T • Motor heating due to a start
Thermal Model - Thermal Capacity Used Motor cooling will be represented by: • The vapour evaporating from the surface of the liquid when the motor is running or stopped will represent the motors ability to dissipate heat. • The fan is representative of the additional cooling effect of the motor’s cooling system which is commonly a fan mounted on the motor shaft.
Motor Protection Standard Overload Curves • 15 standard overload curves • 1 custom curve (FlexCurve) • 1 Voltage dependent curve (469) • Under/Over voltage • Reverse power • Underpower • Under/Over frequency • kvar, PF (Synch. motor) • Amps, kW, kvar, kVA demand alarms • Trip coil supervision (469) • Breaker failure • Incomplete sequence • Service Factor Protection
Hot / Cold Ratio = 15 sec/20 sec or .75 Cold Motor Curve Hot Motor Curve 20 sec 15 sec 6 X FLC
Thermal Model - Thermal Limit Curves Relayoverloadcurve
Thermal Bias RTD and Unbalance Biasing • Hot/Cold motor compensation • RTD Thermal Bias • Min. temperature (40 C) / No biasing • Max. temperature ( Insulation rating) /Thermal capacity =100% • Mid point temperature and thermal capacity • Negative Sequence Current Bias • Accounts for excess rotor heating due to unbalanced voltages (skin effect - Induced current rotating in opposite direction at 2x line freq..) • Not accounted for by curves provided by motor manufacturer
Voltage Dependent O/LCurve Voltage dependent O/L curve • Custom curve for running in overload • Minimum starting voltage • Minimum stall point • Min. accel. intersection point with custom curve • Maximum starting voltage • Maximum stall point • Max. accel. intersection with custom curve • SR469 dynamically shifts curve for all voltages
3 parts of the Curve 1) Locked Rotor 2) Acceleration 3) Running Motor Acceleration Curve at 80% Voltage Motor Acceleration Curve at 100% Voltage
Metering and Monitoring • Phase amps • Differential amps • % load • Ground amps • % unbalance • Voltage • +/-kW (HP), +/-kvar, kVA • Wh, + varh, - varh • PF • Frequency • Demand (A, kW, kvar, kVA and peak demand)
Metering and Monitoring • RTD temperatures • Speed RPM (tach. input) • 4 analog inputs • Learned parameters • Acceleration • Starting current • Starting capacity • Max. RTDs • Min./Max. analog inputs
Maintenance & Diagnostics • Statistical data on: • Number of trips • Type of trips • Number of motor starts • Number of running hours • Last 255 events recorded (time and date stamped) • Cause of last trip • Pre-trip data • All active alarms
Memory Map Example Group Address Description Current 0300 Phase A Current 0301 Phase B Current 0302 Phase C Current 030D Phase A Differential 030E Phase B Differential 030F Phase C Differential
Free PC Software and Firmware • Windows based • Access all: • Actual Values • Setpoints • Status • Event records • Oscillography • Graphical trending • Setpoint programming • Setpoint files • Download updated firmware to Flash memory
Motor Setting Auto-Configuration • Motor Nameplate • Motor Temperature Data • System Configuration • Current Sensing • Voltage Sensing • Motor Starting Supervision
369 Motor Settings Auto-Configurator Report • Motor Settings Auto-Config Report • Clearly Organized • Individual Setting Identified • Report identifies warnings and provides suggestions
Motor Health Report Single-click access to Motor Health Report Reads event history, learned motor parameters, motor start data logger from 369 Applies basic analysis to key motor parameters – Red/Orange/Green results Prepares summary report as PDF file with all key information presented Built into EnerVista™ 369 Setup and included in EnerVista™ Launchpad
Motor Health Report – Motor Stop/Trip History Histogram representation of motor stops and trips Classified by stop and trip causes Simplifies troubleshooting and analysis Quickly identifies motor and system issues
Security Audit Trail – Complete Traceability • Patented Security Settings Report • Only motor protection relay on the market to include this feature • History of last 100 changes • When, # of changes made, method, who, etc. • NERC CIP Compliant