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Motor Starting Technologies Jack Smith – SYD Joe Pickell - RA Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 1 Objective • Review the basic motor starting technologies: – Across the line – Reduced voltage – Variable frequency • Understand the selection criteria for each technology • Review application considerations for each starting technology – – – – Relative cost Effects on available torque Maintenance issues Reliability Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 2 Across The Line Starters • Electromechanical or Solid State switch that closes the motor power circuit. – Motor is either on or off • Various design standards exist for contactors – NEMA – IEC – Definite Purpose • Characteristics – Motor has full voltage available as soon as power circuit closes • Pulls an inrush current 5-7X Normal running current • Motor can produce full torque immediately Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 3 Across the Line Starter - NEMA Advantages •Available up to NEMA size 9, 1600HP @480VAC, 2250A •Simple design, few moving parts, reliable •Proven durability •Versions tested for various applications •Field serviceable •UL and CSA approved •Allen Bradley tested to 10 million operations Limitations •Not touch safe •Physically large •Panel must be drilled and tapped to mount •Cannot be mounted significantly off vertical Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 4 Across the Line Starter - IEC Advantages •Available up to 860A, AC-3 •Modular family includes: •Overloads •MSP’s •Mounting Systems/Busbars •Touch safe design •Versions tested for various applications •Space saving designs, mini versions available •DIN rail mounted •Global approvals Limitations •Life span is application dependent •Typically 1 million operations at rated load •Limited field serviceability Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 5 IEC vs. NEMA Cost / Size / Life Comparison Data Description NEMA Size 1 IEC 18 Amp AC-3 HP Rating 10HP 10 HP Life Operations 10 mil 2 mil List Price $204 $130 Panel Area Required 21.4 in2 7.1 in2 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. Life Comparison Equalizing Life Data Description NEMA Size 1 IEC 18 A AC-3 IEC 38 A AC-3 HP Rating 10HP 10 HP 25HP Life Operations 10 mil 2 mil 10 mil List Price $204 $130 $210 7.1 in2 14 in2 Panel Area Required 21.4 in2 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. Across the Line Starter – Definite Purpose Advantages •Available up to 90A, 1,2or 3 pole versions •Specially tested to HVAC standards •Fast-on connections •DIN rail mounting available •Economically priced approx. 2/3 IEC $ •UL and CSA approvals Limitations •Life span is application dependent •Panel normally drilled and tapped •Very limited field serviceability •No matching overloads Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 8 Across the Line Starter – Solid State Advantages •Available up to 50A, AC-1 or 15A, AC-3 •No moving parts •Touch safe design •Ideal for high duty cycle or high vibration applications •Ideal replacement for mercury contactors •DIN rail mounted •Global approvals Limitations •Heat dissipation can be an issue •No field serviceable parts •No matching overloads •No aux contacts •Approx 1.5x IEC $ Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 9 Across the Line Starter – Vacuum Advantages •Available up to 500HP @ 480 VAC, 600A •Long contact life due to vacuum •Ideal for high duty cycle applications •UL, CSA approvals Limitations •Physical size may be an issue •Approx. 2x IEC $ •Limited offering starting at 200A Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 10 Overload Relays for ATL Starters Overload Protection Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 11 Comply with NEC/CEC Motor running overcurrent protection NEC article 430 - part C CEC rule 28-200 Reduce fire hazard NEC Article 430 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 12 Eutectic Alloy Type • Adjust trip setting by installing various rated heater elements • Manual Reset only Type W Heater Elements Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 13 Eutectic Alloy Type W Heater Elements Resistance Element Thermal Mass To Motor To Power Pawl to Mechanism Which Controls Relay Contacts Thermal Ratchet Stud Memory Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 14 Eutectic Alloy Overload Relay Operation EUTECTIC ALLOY POWER CIRCUIT RATCHET POWER CIRCUIT HEATER PAWL TO STARTER COIL PIVOT TO STARTER COIL CONTACT ACTUATOR CONTROL CIRCUIT CONTROL CIRCUIT Reset Position Tripped Position Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 15 Bi-Metal Theory Bi Metallic Two metals with dissimilar expansion Generated heating causes deflection Adjustable trip setting Manual or automatic reset Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 16 Basic Electronic Overload Advantages • Increased accuracy • Enhanced performance • Easy to select and apply • Greater application flexibility Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 17 Product Overview Feature Overview Insert Molded Power Stabs Latching Mechanism Test Button Reset Button Mechanical Trip Actuator DIP Switches (193-EE, 592-EE only) Trip Status Indicator FLA Setting Dial Control Terminals 95 & 96 / 97 & 98 Load Terminations Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 18 Product Overview Wide 5:1 Adjustment Range • Application flexibility • Simplified product selection with a minimized number of catalog devices, greater overlap • One device covers the range of 4 bimetallic overloads or 19 eutectic heater elements E1 Plus Bimetal 0.1A 90A Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 19 Proper Overload Protection vs. Motor Life Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 20 Reduced Voltage Starters • Basic Functionality – – – – Reduce inrush current during motor start After start motor runs at full rated speed Reduced starting torque = reduced mechanical wear May provide energy savings if peak charges are an issue • Electromechanical – Part Winding • Used with special motors with parallel windings • Reduced starting torque – Wye – Delta • Used with 6 lead delta wound motors • Reduced starting torque – Autotransformer • Reduced starting torque vs. ATL but most per amp of above • Solid State – Uses SCR’s to chop voltage peaks during start up – Electronic controls on SCR’s enable flexible starting profiles Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 21 Economy Solid State Soft Starts Advantages • Up to 100HP @480VAc, 135A •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 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 22 Full Featured Solid State Soft Starts Advantages • Up to 400HP @ 480VAC, 480A •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 • Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 23 Variable Frequency Drives • Basic Functionality – Offers total speed control including ramp up and down – Speed controlled by changing frequency of power to motor – Speed control may result in energy savings • Component class drives – Power Flex 4 – Power Flex 40 – Power Flex 400 • Architecture Class Drives – Power Flex 70 – Power Flex 700 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 24 “Component Class” Drives Optimized for machine-level and stand-alone control “4-Class” Products Performance / Functionality • Most economical Allen-Bradley offering in its power, performance & feature segment • Simple selection, set-up, & operation • Industry-standard RS-485 communications capabilities • Industry-standard power structure features & installation options PowerFlex 40 PowerFlex 400 PowerFlex 4 5 10 20 50 100 Power Rating (HP @ 460V) Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 200 25 Component Drive Applications • Provides a smooth accel/decel – no jerky motion • Fixed acceleration using variable frequency – Important when synchronizing machines or processes • Speed changes “on the fly” • Communication status across network • Critical stopping criteria – – For repeatable and accurate “in position” applications Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 26 Rockwell Automation Strengths • The most simple to use product in its class • Integral keypad with control keys and local pot active out of the box • DIN rail mounting, small package size, Zero Stacking • Same integral keypad as PowerFlex 4 • Expanded I/O, sensorless vector control, add on communications options and timer/counter/Step Logic functionality • PowerFlex 400 is the HVAC drive with standard features aimed at the centrifugal pump and fan marketplace Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 27 Integral LED Keypad Simplifies Start Up • 4 digit LED display indicates parameter number or value • LED indicators for run and direction status • LED indicators for units of parameter values • Programming keys similar to all other PowerFlex products • Three simple programming groups – Display Group – Basic Group – Advanced Group Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 28 Drive Commissioning Made Simple • Just hook up your power wiring and control the drive from the integral keypad – Control keys are active allowing out of the box operation. Status indicators above start key and speed pot indicate when active. • 10 most common application parameters contained in Basic Program Group to simplify programming – – – – – – – – – – P031 Motor Nameplate Voltage P032 Motor Nameplate Frequency P033 Motor Overload Current P034 Minimum Frequency P035 Maximum Frequency P036 Start Source P037 Stop Mode P038 Speed Reference P039 Accel Time 1 P040 Decel Time 1 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 29 PowerFlex 40 – Increased Performance • Excellent motor control, thru 7.5 kW / 15 HP – V/Hz or Sensorless Vector (SVC) modes • Communication – Integral RS485 serial communication – Add-on communication adapters • Expanded I/O – Analog output – 2 digital outputs • Logic Functions – Timer – Counter – StepLogic • Similar to PowerFlex4 − Common parameter structure & set-up – Integral user interface – Common “4 Class” accessories Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 30 Relative Cost Comparison 5-50HP 5HP 15HP 30HP 50HP DP IEC 0.7 0.6 0.8 0.9 1.0 1.0 1.0 1.0 SS NEMA Contactor 2.3 3.4 4.5 2.2 1.5 1.0 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. SS Reduced Voltage VFD 3.7 3.1 3.8 4.3 8.0 11.8 8.5 13.0 31 Relative Cost Comparison 75 – 200HP IEC 75HP 100HP 150HP 200HP 1.0 1.0 1.0 1.0 NEMA Vacuum 3.9 2.4 3.1 2.7 5.5 3.3 2.0 3.1 SS Reduced Voltage VFD 5.5 4.4 3.1 3.0 12.9 9.6 8.0 11.2 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 32 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 33 Copyright © 2005 Rockwell Automation, Inc. All rights reserved. 34