Three-phase Induction Motor - Siemens
sOperating Instructions MTR4.2-003Three-phase induction motorType 1LA8!WARNINGSupply Voltage is hazardous and cancause Electric Shock and burns.Disconnect Power before proceedingwith any work on this equipment.
Table of content11.11.21.31.4Safety information . 1Definitions, warning information . 1Safety and application information . 2Operation in locations subject to explosion hazards . 2Electromagnetic compatibility . 222.12.22.32.42.5Description, technical data . 3Scope of delivery . 3Siemens Service Center . 3Applications . 3Design of the motor . 3Main Terminal Boxes . 433.13.23.33.43.53.63.73.8Transport, installation and assembly . 7Transport, storage . 7Installation . 8Aligning . 9Mounting . 10Connecting the ground conductor . 10Connection of the motor . 11Connection to the converter . 13Converter operation on a grounded network . 1344.14.24.34.44.5Commissioning . 14Preparations . 14Measures to be taken prior to commissioning . 15Monitoring the temperature of the stator winding . 15Energizing . 15De-energizing . 1655.15.25.3Operation . 17Safety information . 17Stoppages . 17Fault diagnosis table . .26.3.36.3.46.3.56.3.66.3.76.3.86.3.9Maintenance . 20Maintenance . 20Preparations for maintenance . 20Bearings . 20Regreasing with sealing grease (option for increased degree of protection) . 21Servicing . 21Servicing instructions . 21First service after installation or repair . 21Main service . 22Repair . 22Preparations for overhauling / repairs . 22Dismantling . 22Dismantling instructions . 22Re-assembly . 23Notes on assembling the bearing seal . 24Assembling the fan . 24Bolt locking devices and tightening torques . 24Spare Parts . 24Exploded View – 1LA8 Motor . 25
1Safety information1.1 Definitions, warning informationWarningThe data and recommendations specified in allthe instructions supplied, and in all other relatedinstructions, must always be observed in orderto avoid hazardous situations and the risk ofpossible injury or damage.Furthermore, the pertinent national, local andplant-specific regulations and requirementsshould be kept in mind!Special designs and other versions may vary intechnical details! If in doubt, be sure to contactthe manufacturer, quoting the type designationand serial number, or have maintenance workdone by one of Siemens Service Centers.Qualified personsOnly qualified persons who have carefully read andunderstood the content of this documentation shouldbe entrusted with the commissioning and operation ofmachines, equipment or systems. Qualified persons asfar as the safety instructions given in thisdocumentation are concerned are those who have thenecessary authorization to commission, earth andidentify equipment, systems and circuits in accordancewith the relevant safety standards.Safety guidelinesThis documentation contains instructions, which mustbe followed closely in order to ensure personal safetyand avoid damage to the equipment and machines.Personal safety instructions are highlighted in themanual by a warning triangle, while damageavoidance instructions are not. They are marked asfollows depending on the level of danger:DangerDanger means that death or grievous injury willoccur if the appropriate precautions are nottaken.WarningWarning means that death or grievous injurymay occur if the appropriate precautions are nottaken.CautionCaution with a warning triangle means thatminor personal injury may occur if theappropriate precautions are not taken.CautionCaution without a warning triangle means thatdamage to property may occur if theappropriate precautions are not taken.NoticeNotice means that an undesirable result or state mightoccur if the relevant instructions are not followed.NoteNote draws particular attention to an important itemof information about the product, its use or thecorresponding section of the documentation, whichcould be useful to the user or operator.Proper usagePlease pay close attention to the following:WarningThe electrical equipment contains componentsthat are at a dangerous voltage. Before any workis carried out, therefore, it must be ensured thatthe equipment is isolated from the supply.Only qualified persons may work with thisequipment.These persons must be familiar with allinstructions and precautions to be taken /specified in this documentation that are relevantfor safety.Safe and satisfactory operation of this motorpresumes satisfactory transport, proper storage,installation and assembly and carefulsubsequent operation and maintenance.This motor may only be used for the applicationsspecified in the catalog and the technicaldescription, and only in conjunction with thirdparty devices and components recommendedand/or approved by Siemens.Failing to adhere to these instructions mayresult in severe injury and/or damage toproperty.National safety regulations must be closelyobserved.1
1.2 Safety and application informationThe safe use of electrical machines1.3 Operation in locations subject toexplosion hazardsNoteDanger1LA8 Motors are designed and manufactured foroperations in safe zones onlyThese electrical machines are designed for usein industrial power systems.Rotating or live and uninsulated parts pose adanger.There is consequently a risk of fatal or severepersonal injury or substantial damage toproperty if the necessary covers are removedwithout authorization or if the equipment ishandled improperly, operated incorrectly ormaintained inadequately.If the motors are used outside industrial areas,the installation site must be safeguarded againstunauthorized access by means of suitableprotection facilities (e.g. fencing) andappropriate warning signs.The persons responsible for the safety of the systemare under an obligation to ensure that: The basic planning work for the system and allwork relating to transportation, assembly,installation, commissioning, maintenance andrepairs are carried out by qualified persons andchecked by responsible, suitably skilled persons.DangerBinding clarification of the local risks and of anymeasures necessary is only possible by the userof the installation in agreement with thesupervisory authority responsible.Installation-specific ignition hazardsThe criteria for the respective zonal classification arenot harmonized and the assessment of the operationalrisks, the local operating conditions and the variousmonitoring methods is not uniform. Accordingly, theremedial measures recommended by the supervisoryauthorities also differ in some cases, depending on theauthority’s area of responsibility. It is not possible forthe machine manufacturer to issue generallyapplicable recommendations in this respect.NoteBinding clarification of the local risks and of anymeasures that should be recommended is onlypossible by the user in agreement with the supervisoryauthority responsible for the respective installation. These instructions and the motor documentationare made available at all times while work is inprogress.1.4 Electromagnetic compatibility The technical data and specifications relating to thepermissible installation, connection, ambient andoperating conditions are taken into account at alltimes.Notice The system-specific erection and safety regulationsare observed and personal protective gear is used. Work on these machines, or in the vicinity of thesemachines, by unqualified persons is prohibited.These instructions therefore only contain theinformation, which is necessary for the motors to beused by qualified persons in accordance with theirintended purpose.NoteWe recommend engaging the support and services ofyour local Siemens service center for all planning,installation, commissioning and maintenance work.Instructions relevant for safetyIf the load torque is very irregular (e.g. when driving areciprocating compressor) a non-sinusoidal motorcurrent will be induced whose harmonics might bringabout an excessive reaction on the supply system andso cause excessive emitted interference on the powersupply connecting leads.NoticeIf operated through a frequency converter, the emittedinterference is varying in strength, depending on thedesign of converter (type, interference suppressionmeasures and manufacturer). In order to avoidexceeding the limit values on the drive system,consisting of motor and converter, the EMCinformation given by the converter manufacturer muststrictly be observed. On motors with integratedsensors (e.g. PTC thermistors) it is possible thatinterference voltages caused by the converter occur onthe sensor lead.If using motors with integrated sensors, the operatorhimself must ensure sufficient interference immunityby selecting a suitable sensor signal lead and a suitableevaluation unit.2
2Description, technical data2.1 Scope of delivery IS: 12065: Permissible limits of noise level forrotating electrical machines.Checking the scope of delivery for completeness IS: 12075: Mechanical vibration of rotatingelectrical machines with shaft heights 56mm andhigher – Measurement, Evaluation and Limits ofVibration severity.When you take receipt of the delivery, please checkimmediately whether the scope of the delivery matchesup with the accompanying documents. Siemens will notaccept any warranty claims relating to items missingfrom the delivery that are submitted later.Register a complaint about:– Any transport damage detected immediately withthe delivery agent.– Any defects/incomplete delivery detectedimmediately with the SIEMENS representativeresponsible.These Operating Instructions belong to the scope ofdelivery and must be kept where they can be easilyaccessed.2.2 Siemens Service CenterContact for further informationDetails about the design of the three-phase motorsupplied and about the permissible operating conditionsare described in these Operating Instructions.If you have any questions or suggestions, or if yourequire further information, please contact theSiemens Service Center.2.3 ApplicationsOverview1LA8 three-phase AC machines have been designedfor a very wide range of drive applications and energyconversion applications. This series distinguishes itselfas a result of its ruggedness, high lifetime andreliability. Not only this, it is extremely versatile, whichallows it to be optimally adapted to the particularapplication and function.A description of the motor and permissible operatingconditions are specified in this documentation.2.4 Design of the motorStandardsThe motors are compliant with the followingstandards: IS: 325: Specification for three phase inductionmotors IS: 900: Code of practice for installation andmaintenance of induction motors. IS: 4691: Degree of protection provided byenclosure for rotating electrical machinery IS: 7816: Guide for testing insulation resistance ofrotating machines. IEC: 60034-1: Rotating electrical machines – Part 1:Rating and Performance. IEC: 60034-5: Degree of protection for rotatingelectrical machines.Cooling and ventilationThe series 1LA8 motors are totally enclosed fan-cooledthree-phase squirrel cage motors with an internal aircooling circuit for cooling.Located at the non-drive end of the stator housing isan air intake cowl that guides the external air. Theexternal air is drawn in through an opening in the airintake cowl and flows axially across the outer coolingribs of the motor frame. The fan impellers for the innerand outer cooling airflow are mounted on the motorshaft. The cooling method is as per IC411 (or IC4A1A1)of IEC 60034-6.CautionNormally, external fans for two-pole motors areunidirectional, and for machines with four ormore poles are bidirectional. Machines withunidirectional external fans are identified on theFan cowl with an additional label showing thedirection of rotation. The internal fans aregenerally bidirectional. In the event that the levelof cooling provided by the internal coolingsystem is not sufficient it is also possible to attacha separate fan. This type of fan provides asufficient level of cooling irrespective of thespeed of the main motor. Temperature sensorsare integrated in the stator winding to monitorthe winding temperature. Various supplementarydevices can be integrated or mounted,depending on the order. These include, forexample, anti-condensation heating, bearingtemperature monitoring or other devices.Rotor and rotor windingThe rotor assembly is pressed onto the shaft togetherwith the squirrel cage winding. The drive end of theshaft usually has a cylindrical shaft end.StoringThe motors are equipped with different types ofrolling-contact bearings depending on the version andthe operating conditions described in the order. Thedifferent types are listed on the lubrication plate of themotor. In converter operation an insulated bearing isusually installed on the non-drive end.3
CautionCompliance with the permissible loads for theforces at the end of the shaft must be ensuredin accordance with the catalog data, asotherwise bearing damage may occur.2.5 Main Terminal boxesThe terminal box can be arranged either on the left orright of the machine. It is not possible to subsequentlyswap the position to the other side of the machine at alater date. Please consult Siemens if you subsequently4need to convert the machine to the next larger size ofterminal box. Depending on size, the followingterminal boxes are generally used for connecting thecables:Motor TypeMain Terminal Box1LA8 31-2.81XB7 6221LA8 353/355-2.81XB7 6221LA8 357-6.81XB7 6221LA8 357-2.41XB1 6311LA8 40-41XB1 631
Main Terminal Box - 1XB7 6225
Main Terminal Box - 1XB1 6316
3Transport, installation andassembly3.1 Transport, storageTransport damageThe shipping company must be notified immediatelyof any damage detected after delivery of the machine.The machine must not be put into operation if anydamage is found.Tightening torques for the shaft bolt of the rotorlocking deviceThread in theshaft endTighteningtorquePreloadM2050 Nm12 kNM24100 Nm20 kNM30180 Nm32 kNTransportationWarningCautionThe supplied rotor-locking device must bemounted during transportation in order toprevent damage to the motor. Do not removethis device until before the power take-offelement is fitted. If the motor has to betransporte
A description of the motor and permissible operating conditions are specified in this documentation. 2.4 Design of the motor Standards The motors are compliant with the following standards: IS: 325: Specification for three phase induction motors IS: 900: Code of practice for installation and maintenance of induction motors.
3.0 Dynamic Modeling of three phase squirrel cage Induction Motor for Speed Torque Analysis The dynamic modeling of three phase squirrel cage induction motor is done by using a simulink designed model for three phase induction motor fed by PWM inverter. Table IV: Parameters Description Table of three phase Squirrel Cage Induction Motor I L (Amp)
Although single phase induction motor is more simple in construction and is cheaper than a 3-phase induction motor of the same frame size, it is less efficient and it operates at lower power factor. 1.5 WORKING OF SINGLE-PHASE INDUCTION MOTOR: A single phase induction motor is inherently not self-staring can be shown easily.
8.2.1.1 Stator of Three Phase Induction Motor The stator of the three phase induction motor consists of three main parts :. i. Stator Frame It is the outer most part of the three phase induction motor. Its main function is to support the stator core and the field winding. It acts as a covering and it provide
speed control of induction motor obtain wide speed range of induction motor with smooth drive control, reduces torque ripples, noise and also reduces loss. So, that it will improve the efficiency of induction motor. Induction motor has wide speed range from 300 RPM to 1415 RPM or rated speed of particular induction motor. For the digital speed .
Phase Induction Motor In Fig.6. the time response of electromagnetic torque of three-phase induction motor is expressed. The electromagnetic torque of three-phase induction motor is firstly variable in 0 to 0.4 second. The rated torque is reached at 0.8 seconds. Global Journal of Researches in Engineering Volume XII Issue vvvv 3
Three-Phase Squirrel-Cage Induction Motor Drive 2.1 Introduction This chapter presents an overview of the principle of three-phase squirrel-cage induction motor drive. First, the model and the related equations of three-phase induction machine are described and presented in both abc and
3.1 3-phase AC Induction Motor Drives The AC induction motor is a workhorse with adjustable speed drive systems. The most popular type is the 3-phase, squirrel-cage AC induction motor. It is a maintenance-free, less noisy and efficient motor. The stator is supplied by a balanced 3-phase AC power source. The synchronous speed ns of the motor is .
Lesson 12a: Three Phase Induction Motors ET 332b Ac Motors, Generators and Power Systems Lesson 12a_et332b.pptx 1 Learning Objectives Lesson 12a_et332b.pptx 2 After this presentation you will be able to: Explain how a three-phase induction motor operates Compute the synchronous speed of an induction motor and the slip between motor rotor and stator
