WEG Synchronous Motors Technical Article English

SYNCHRONOUSMOTORS

Synchronous MotorsSynchronous Motors

Motores SíncronosMotores Síncronos

TABLE OF CONTENTS

INTRODUCTION.....................................................................3

ADVANTAGES.........................................................................5

OPERATION CHARACTERISTICS...........................................6

EXCITATION TYPES...............................................................8

CONSTRUCTIVE COMPONENTS.............................................9

ACCESSORIES......................................................................11

CONSTRUCTIVE CHARACTERISTICS...................................12

INSULATION SYSTEM..........................................................13

TESTS...................................................................................13

SYNCHRONOUS MOTOR SELECTION...................................14

APPLICATIONS..........................................................................15

SYNCHRONOUS MOTOR SPECIFICATION......................................16


03

INTRODUCTION

The word “SYNCHRONOUS” is originated from Greek. The prefix“SYN” means “with” and “CHRONOS” means “time”.A synchronous motor literally operates “in time with” or “insynchronism with” the power supply system.Due to the fact the synchronous motors are fitted with specialoperating characteristics, industries are more and more usingsuch motors.Included in the main reasons for the industries to specifySYNCHRONOUS MOTORS to drive a wide range of applicationsare the high efficiency and the fact they are suitable to operateas synchronous compensating machines for power supplyfactor correction.In addition to that, these motors also feature high torque, constantspeed under load variation, along with low maintenance costallowing major economical and operational advantages to endusers.

Operation Principle

Stator and stator winding (armature) of Weg synchronousmotors are identical to components of three phase inductionmotors.Identical to induction motors, the current that goes throughthe stator winding generates a rotating magnetic flow thatcirculates around the air gap.

Stator rotating field - When the current goes through thecoil, a magnetic field is generated which is based on coil axisand is proportional to the current value.

Figure 1 shows a waveform of a balanced three phase systemconsisting of 3 sets of coils placed symmetrically on the arearesulting in a 120º angle.

Figure 2 represents a three phase motor winding. If thewinding is powered by a three-phase system, currents I1, I2and I3 will create at the same time their own magnetic fieldsH1, H2 e H3. These fields are spaced between them by a 120ºangle as well.Besides that, as they are proportional to the respective currents,they will be de-phased in time, also between them by a 120ºangle.The resulting H field, at each point, will be equal to the graphicsum of the 3 magnetic fields H1, H2 e H3 on that point.

Figure 3 shows this graphic sum for 6 successive points.

On point (1), figure 2 shows that field H1 is on maximumstage and that fields H2 and H3 are negative and with samevalue which is equal to half of H1.The 3 fields represented on figure 3 (upper part) take intoconsideration that the negative field is represented by an arrowpointed to the opposite direction in comparison to what wouldbe normal. The resulting field (graphic sum) is shown on thebottom part of figure 3, position (1), having the same directionof phase 1 winding.Repeating the construction for points 2, 3, 4, 5 and 6 of figure1, the resulting H field presents “constant” intensity. However,its direction will “rotate” until completing a turn at the end ofthe cycle.

Figure 1

Figure 2

Figure 3

Cycle

Time


Synchronous Speed - The motor synchronous speed (rpm)is defined by the rotating field speed that depends on themotor pair of poles (p) and on the power supply frequency (f).The stator winding can consist of one or more pairs of polesthat are distributed alternatively (one “north” and another“south”) along the magnetic core outer side.The rotating field goes through a pair of poles (p) at eachcycle. Considering the winding has poles or pair of poles, thefield speed will then be:

The synchronous motor rotor is built with a number of polescorresponding to the stator winding number of poles.Under normal operation, there is no relative movement betweenrotor poles and stator magnetic flow, that is, they are in perfectsynchronism. As a result, there is no induction of electric voltageinto the rotor by the mutual flow and then there is no excitationoriginated from the AC power supply.

Depending on the type of rotor used (cylindrical or salientpole), the pole coils can be built with insulated copper wireturns or with copper bars.

The field excitation is done through a DC system. When goingthrough the field winding, the poles are polarized magneticallybecoming alternatively north pole and then south pole.

The DC excitation can be applied to the field through the brush-holders and slip rings, or through a brushless system andthrough electronic control (brushless).

pf.60 rpm =

04


Power Factor Correction

Electric power systems are based not only on the generatedactive power supply in kW, but also on the power factor onwhich it is generatedWhenever the load power factor is below the specified values,the consumer may be subject to penalties.These penalties (fines) occur due to the fact that the low powerfactor results in increase of required reactive power (kVAr)and, as a consequence, an increase of the power supplytransmission and generation equipment capacity.

On industries, inductive reactive load are predominant. Theseare usually low size or low speed induction motors. Such loadsrequire considerable portion of reactive power(kVAr) asmagnetization current.

Other than applying bank of capacitors to supply the powersupply with reactive power, synchronous motors are normallyused for such purpose.

Power factor of synchronous motors can be easily controlledas they are fitted with an independent excitation source. Thisway, power factor can be increased without generating reactivepower (motor with PF=1.0) or generate required reactive power(motor with PF=0.0).So depending on the application, a synchronous motor cansupply the required power with substantial power reduction onthe whole system.

ADVANTAGES

Due to their special operating characteristics, synchronousmotor applications usually result in economical and operationaladvantages to end users.Included in the economical advantages of using synchronousmotors are:- High efficiency- Power factor correctionIn addition to that, there are other specific operationaladvantages of using synchronous motors as follows:- Special starting characteristics- Constant speed under load variation- Reduced maintenance cost

High Efficiency

Associated to the initial purchasing cost of a synchronous motor,further gains resulting from low operational cost should bealso considered.On those cases, where just the efficiency aspect is taken intoaccount when specifying a motor, a synchronous motor withPF=1.0 is usually the solution.When the reactive power (kVAr) is not required and only theactual power (kW) is applicable, the current is minimizedresulting in lower stator winding loss I²R.Once the required field current is the minimum applicable, therewill be lower field winding loss I²R. Except for those cases wherehigh torque is required, the low stator winding losses allow asynchronous motor with PF=1.0 to be designed in lower size ifcompared to a synchronous motor with PF=0.8 of equal powerrating.Hence, synchronous motor efficiencies with PF=1.0 are normallyhigher than induction motor efficiencies of equal power rating.

Comparison between efficiency levels of synchronous motorswith PF= 0.8, PF=1.0 and induction motors.

05

Eff

icie

ncy

(%)

Power Rating (kW)

Induction Motor

Special Starting Characteristics

Large ball mills for iron mines, cement plants and compressorsare few examples of applications that required high startingtorque (150 to 200 % of the rated torque).Due to power supply system limitations, low starting currents(locked rotor) are usually required.A combination of high torque with low starting current can bebetter achieved with the application of synchronous motorswithout affecting operating characteristics.Starting current reduction can be usually achieved with a specialdesign of stator and amortisseur winding.Starting the motor with reduced voltage is also an alternativeapplied so as to have the current reduced, although, with torquereduction.


Constant Speed

Independently of load variations and as long as the load ismaintained within the motor pull-out torque limitation, thesynchronous motor average speed is kept constant.This occurs due to the fact that the rotor poles remain lockedin relation to the rotating magnetic field that is generated bythe stator winding.Then, synchronous motor speed is kept constant either onoverload variations or on voltage drop cases, in addition tofollowing pull-out torque limitations.On certain applications such as on pulp and paper mills, theconstant speed results in superior uniformity and quality ofthe supplied product.

Reduce Maintenance Cost

Since they do not require slip electric contacts for their operation, BRUSHLESS synchronous motors are not manufactured withbrushes nor with slip rings. Hence, maintenance, inspection and cleaning on these components are not required.

Inertia

When driving high inertia loads, synchronous motors aredesigned in larger frame sizes so as to meet accelerationconditions.The time period the motor takes to accelerate causes amortisseurwinding overheating. Therefore, this motor must be designed insuch a way to meet the starting conditions.

The correct load inertia definition, associated withmotor and load torque analysis are quite importantallowing this motor to meet starting and accelerationconditions.

Starting

The amortisseur winding, that operates as a squirrel cage of aninduction motor, is intended to guarantee synchronous motorstarting and acceleration. This way, starting and pull-intorque’s vary with the square of the applied voltage,and the starting current is proportional to the appliedvoltage, exactly as on induction motors.

OPERATION CHARACTERISTICS

TORQUES

A synchronous motor must be always designed taking into accountdriven load characteristics, in addition to torque’s and inertia.

a) Starting torqueIt is the torque that the motor must supply to drive the standstillload resistant torque, that is, it is the load starting torque.

b) Pull-in TorqueIt is the torque that the motor must supply to reach the correctspeed, where the excitation field application will take the motorto the synchronism (pull-in torque).

c) Pull-out TorqueIt is the torque that the motor must supply to keep the motorunder synchronism in case of momentary overloads with reted

excitation.

06


Starting characteristic curve of asynchronous motor at full voltage

If the specified motor torque, at 95% of the synchronous speedis equal to the load pull-out torque, this motor can not supplythis torque at 98% of the synchronous speed and then suchmotor will not synchronize.This way, to ensure motor starting and synchronism, carefulanalysis of the starting torque curve along with load resistanttorque curve must be carried out.

Asynchronous Starting

The main starting method applied on synchronous motorstarting is the asynchronous starting through a squirrel cagewith the short-circuited winding rotor or connected to aresistance, usually called starting resistance or dischargeresistance.Through asynchronous starting, the rotor accelerates at a speedvery close to the synchronous speed, with a slight slip inreference to the rotating field. On this point, a direct current isapplied to the rotor winding and then taking the motor tosynchronism.On brush-supplied machines, a field application relay is used,while on brushless motors a electronic control circuit is applied,which is installed attached to a rotating rectifier disc. Thiselectronic circuit and the field application relay are intended tomanage the synchronous motor starting sequence, since the rotorshort circuits up to the field current application.

A synchronous motor starts exactly like an induction motor andthen it accelerates the load up to the point where the motortorque becomes the same as the load resistant torque. Usuallythis point occurs with 95% of the synchronous speed or abovethat, and on this condition, the excitation voltage is applied tothe motor, and the rotor synchronizes, that is, it will acceleratethe combined rotor and motor inertia plus the load inertia up toprecise synchronous speed.Driven load characteristics will determine acceleration andsynchronism conditions.On high resistant torque loads, the amortisseur winding mustmake the motor and load torque accelerate at a time periodhigher than that for a shorter resistant torque.

The proper amortisseur winding design requires preciseknowledge of the load resistant torque.

Based on the synchronous motor starting characteristic curve,starting torque decreases as it gets close to the synchronousspeed.On load applications with resistant torque parabolic curve andconsidering that at 98% of the synchronous speed, the valueof such torque is equal to the load rated torque, the motor isrequired to supply a torque equal or higher than the load torqueon this point.

07


Starting Current

On Brushless synchronous motor starting, thefield winding is short-circuited through theelechome circuit.While motor remains on standstill, the fieldcurrent frequency is initially equal to powersupply frequency (60Hz for power supply of60Hz) and reduces as the motor speedincreases.When the excitation is switched-on, motorspeed must be close to synchronism speed(around 95% of the synchronism speed), andthe field current frequency will remain around3Hz.The stator current also varies on the startingand then it becomes stable after motorsynchronism.

Stator current (Is) and rotor current (Ie) performance onasynchronous starting

1) Starting point

Synchronous motors require a DC power supply topower the field winding (rotor winding), which isusually done through slip rings and brushes (staticexciter) or through a brushless rotating exciter.

1. Static exciter (with brushes)Synchronous motorssupplied with staticexciter are fitted with sliprings and brushes thatallow current powering ofthe rotor poles throughslip contacts.The DC power supply forthe poles must comefrom an AC/DC converterand static controller.

EXCITATION TYPES

2. Brushless exciterSynchronous motors with brushless excitation system are fittedwith a rotating exciter, normally installed on the non-drive endof the motor.The exciter operates as an AC generator with the rotor attachedto the motor shaft. The rotor is fitted with a three phase windingand the stator consists of alternating poles (north and south)and powered by an independent DC source.This three phase winding is connected to rectifier bridge. Thecurrent generated on the rotor is rectified and intended to powerthe motor field winding. The amplitude of such field current canbe controlled through therectifiers that power theexciter stator f ield.Synchronous motors withbrushless excitation requirelow maintenance cost oncethey are not fitted withbushes.Since they are not builtwith slip electric contacts,avoiding sparking,synchronous brushlessexcitation motors arerecommended for explosive atmosphere applications.08

Is

Ie

2) Rotor frequency decreases as

the speed increases

Is

Ie

Stator Current

4) Rotor and stator current stability

Is

Ie

Stator Current

3) Point when the field is switched-

on and the motor synchronizes

Is

Ie

Stator Current


STATOR

Frame - It is mainly intended to support and protect thelamination core and stator winding.The frame can be constructed in horizontal or vertical mountingconfigurations and with degree of protection that meets applicationcharacteristics.It is manufactured with steel plates and welded with MIGwelding resulting in a solid and rugged structural construction.The whole frame construction is duly treated for stress releasecaused by welding process.This construction results in an excellent structural piece so asto withstand mechanical strengths originated from eventualshort-circuits and vibrations, and then making the motorsuitable for the most severe applications.The frame inner part consists of bars for lamination core fasteningto the winding.Usually the frame is based on a metallic rigid base (steel plate)and this part, in its turn, is based on a concrete foundation.The metallic base is fastened to the concrete base throughstuds.

Wound stator -Consisting of staticmagnetic parts, thewound stator includesthe silicon laminationcore and the statorwinding. The last oneoperates as AC powersupply to generate therotating magnetic field.

CONSTRUCTIVE COMPONENTS

Lamination core - Consisting of silicon steel lamination oflow losses, pressed, and the set is fastened through metallicbars or a bar-designed system.

EXCITER

It is intended to supply magnetizing current to the motor fieldwinding. The brushless exciter consists of rotor, stator, rectiferbridge and discharge circuit. Tthe static exciter consists of slipring and brushes and depends on an external source to powerthe motor field.

ROTOR

Depending on motor constructive characteristics and on theapplication, rotor can be built with cylindrical or salient poles.The rotating active parts include rotor ring, field winding andamortisseur winding.The field poles are magnetized through the exciter direct currentor directly through slip rings and brushes; they gear themselvesmagnetically by the air gap and rotate in synchronism with thestator rotating field.The synchronousmotor rotor fitted withsalient poles consistsof shaft, polar ring andpoles.The poles are builtwith laminated steelplates that are fixedwith steel bar andwelded on the ends.The field coils are constructed with enameled copper wires orflat copper bars.

09

Salient pole rotor


Once they have been wound and impregnated, poles are fixedto the shaft or to the polar ring with the application of boltsfrom top or bottom part of the pole, or connected through dovtail.The amortisseur winding is fitted in the poles and, dependingon the motor design, it is built with copper bars or other material.After final assembly and impregnation, the complete rotor isbalanced dynamically at 2 planes.The synchronous motor rotor of cylindrical poles consists ofshaft, lamination core and pole winding.The winding is installed in the rotor slots forming the poles.

Shaft - The shafts are constructed of forged or laminated-steeland machined exactly as per specifications. The shaft end isusually cylindrical or flanged.

Amortisseur winding - This is fitted in the slots placed at thepolar shoes of the salient pole rotor or an external surface of thecylindrical pole rotor. Consisting of bars that go through the slotsand are short-circuited at the ends and then forming a squirrelcage.

The amortisseur winding operates on synchronous motorstarting, along with ensuring speed stability undersudden load variations.

Cylindrical pole rotor

BEARINGS

Based on the application, synchronous motors can be suppliedwith grease-lubricated ball or roller bearings or oil lubricatedsleeve bearings.Sleeve bearings can be naturally lubricated (self lubricated) orwith a forced lubrication system (independent lubricationsystem).

Ball or roller bearings -Depending on the speedand thrusts they aresubmitted to, these greaselubricated bearings can besupplied either with ball orcyl indrical rol lers. Oncertain specif icapplications, specialbearings can be alsosupplied.

Naturally lubricated sleeve bearings - When the rotor turns,the lubricating oil is spread out by the internal oil ring and

transferred directly tothe shaft surfacecreating a layer of oilbetween the shaft andthe bearing l inersurface.The friction heating isdissipated just byradiation orconvection. However,the ambient

temperature must be informed when specifying a motor so as toensure natural cooling.

Forced Lubrication - The lubricating oil circulates around thebearing through an independent oil circulation system and, ifrequired, it is cooled down through an independent hydraulicsystem.This system isrequired when thenatural bearinglubrication comingfrom the internal oilring is not enoughdue to the specificspeed required ordue to high frictionlosses.10


Weg synchronous motors are supplied with standard accessoriesrequired for correct operation and monitoring of the maincomponents.When specifying a motor, the end user must inform the requiredaccessories that should be included in the design and motormanufacture.

Accessories (supplied as standard)- Stator winding temperature detectors PT-100- Bearing temperature detectors- Space heaters

Special Accessories- Brake disc- Brake- Vibration detectors- Encoder- Frame lifting device

Optional Accessories- Temperature detectors for air inlet and outlet- Water flow valve- Water flowmeter- Oil flowmeter- Oil flow sight- Water flow sight- Hydraulic unit for bearing lubrication- Oil injecting system under pressure for motor starting andstop(Hydrostatic Jacking)- Oil thermometer (bearings)- Water thermometer (heat exchanger)- Air thermometer (Cooling)- Anchorage plate

ACCESSORIES

Thermometer

Bearing PT - 100

11


CONSTRUCTION

Weg synchronous motors are manufactured in B3, D5 or D6mounting configurations and with grease lubricated ball or rollerbearings or oil lubricated sleeve bearings.

Sleeve bearings can be mounted on pedestals attached to theendshields which make part of the motor.High speed motors are usually built with relatively long corelength if compared to its diameter.While low speed motors are usually built with relatively shortrotor core if compared to its diameter.

COOLING SYSTEMS

The cooling systems most commonly used are:- Open self-ventilated motors, Degree of Protection IP23;- Enclosed motors with air-air heat exchanger, Degree ofProtection IP54 to IPW65;- Enclosed motors with air-water heat exchanger, Degree ofProtection IP54 to IPW65.

CONSTRUCTIVE CHARACTERISTICS

Besides the cooling methods mentioned above, motors can besupplied with forced ventilation, air inlet and outlet by ducts,and other cooling methods, always meeting installationenvironment and application characteristics.

Synchronous motor

Mounting configuration: B3

Enshield bearings

Synchronous motor

Mounting configuration: D6

Pedestal bearings

Mounting Configuration: D6


Mounting Configuration: D6


Enclosed motors

Open motors

12


On High Voltage Motors - Coils are pre-fabricated withrectangular shape copperwire, coated with mica tapeand epoxy resin impregnated.They are then heated up andcured result ing in highwinding mechanical strength.This process is calledpolymerization and provides

motor extended life time.Coils are fitted in the stator slots, insulated from the statorlamination core with class “F” (155°C) insulating material andfastened by fiber glass or magnetic wedges.The copper wires that form the coils are insulated withappropriate class “H” (180°C)enamel.

The stator is then submitted tohi-pot test and short-circuitbetween turns:- Surge Test before and afterthe impregnation.

INSULATION SYSTEM

Impregnation - Once coils have been inserted, slots closed,connections and coil heads tied, the wound stator is vacuumand pressure impregnated by applying class H solvent-free epoxyresin, ensuring excellent electric, mechanical properties to Weginsulation system, in addition to providing weathering resistance.Epoxy resins are ideal for impregnation once they offer, uponcure, superior resistance to weathering which is typical forenvironments where electric rotating machines operate.Considering they are 100% solid resins, that means, solvent freecomposition, they can ensure major homogeneity and preventfrom occurring insulation bobbles after polymerization and finalcure.

Routine TestsVisual inspection testAir gap checking and bearing tolerancesWinding Ohmic resistanceInsulation resistance.Temperature and space heater inspectionBearing and rotation direction markingVibration checkingNo load testShort-circuit curveHi-pot testExcitation system test

Type testsTemperature rise testNo load curve (V curve)OverspeedLoss and efficiency testWaveform measurementPolarization indexSynchronous motor starting

TESTES

Weg synchronous motors are testedin accordance with IEC34 Standardin its modern testing laboratory forlow, medium and high voltagemotors in output ratings up to10,000kVA and voltage range up to15,000V, with full computerized andhigh precision monitoring.Tests are grouped in threecategories: routine, type and specialtests.Routine tests are performed on allmotors produced. Besides routinetests, type tests are normallyperformed randomly or undercustomer request.Special tests are performed onlyupon customer request.

Special testsNoise level testInstantaneous short-circuitShaft voltage checkStarting current 13


Synchronous motors must be specified based on their

application, that is, based on their service duty, resistanttorque curve and inertia curve. The last two aspects areessential items for motor starting analysis, while serviceduty is important for correct thermal design.

Power factor and excitation type are also important aspectsto take into account for motor specification. Environmenttype defines the motor degree of protection.

Resistant torque and load inertia

When specifying synchronous motors it is quite relevant to

know driven load data.Resistant torque curve and load inertia have direct influenceon motor starting characteristics.To drive high inertia loads, synchronous motors are built in

larger frame sizes so as to meet acceleration conditions.Considering that a synchronous motor starts through itssquirrel cage (same as on induction motors) and with rotorwinding short-circuited (or closed in a resistance), the

correct material used on dump bar (usually built with copperor copper alloys) and their geometry are essential to definemotor starting characteristic curve. This curve must be alwaysdefined based on load resistant torque curve.

Besides ensuring the starting through the squirrel cagegenerated torque, the dump bars must be also designed insuch a way to allow heat dissipation generated during motorstarting.

SYNCHRONOUS MOTOR SELECTION

In reference to this aspect, load inertia will have a great

influence on starting time and on the heat to be dissipated bythe bars.

Theoretically, it is not correct to say that a synchronous

motor used on certain application (ex. pump), can be usedon another different application (ex. exhauster).

Service Duty

The correct specification of a synchronous motor ratedpower must consider the motor service duty with overloadfrequency existing on such duty.

Power factor

Whenever power factor correction is required on a

synchronous motor application, this required power factormust be specified previously. This means that a motordesigned to operate with unit power factor can not supplythe same rated output power under lower power factor.

Environment characteristics

The environment where the motor will be installed must

be analyzed before specifying such motor. Environment typedefines the Degree of Protection and motor cooling method.Explosive atmosphere application motors require brushlessexcitation.

Ambient temperature and altitude considered whenspecifying a motor are 40ºC and 1000m above sea level.If motor operation environment presents values above thosementioned above, it is important to reconsider new data

when specifying this motor.

14


Weg synchronous motors are manufactured specificallyto meet every application requirements. They are used on all types of industry including:

Mining (crushers, mills, conveyor belts and others) Steel plants (laminating machines, fans, pumps,compressors)

Pulp and paper (extruders, chippers, debarkers,compressors, grinders)

Sewage systems (pumps)

Chemical and Petrochemical (compressors, fans,exhausters)

Cement (Crushers, mills, conveyor belts)

Rubber (extruders, mills, mixers)

Fixed speed

Synchronous motor applications with fixed speed arerecommended due to low operational cost once theyoffer high efficiency and can be used as synchronouscompensating machines for power factor correction.

Recommended motors for this application are thosewith brushless excitation.

APPLICATIONS

Variable speed

Synchronous motors with variable speed are recommendedfor applications with high torque, low speed and wide speedadjusting range.

Depending on load and environment characteristics, motorconstruction for such applications can be supplied with orwithout brushes,.Due to their higher efficiency level, reduced size and higheroutput rating capacity, synchronous motors can replace DCmotors on high performance applications.

On several cases, a motor with lower torque values comparedto standard values can be actually applied. This brings positivereduction on motor starting current, resulting in less electricsystem troubles on starting, along with reduction on mechanicalthrusts resulting from motor winding.For a correct design and application of Weg synchronousmotors, we recommend to supply complete application data.

15


Quantity:__________ Application (driven machine):_________________________Output rating (kW):_________ Voltage (V):________ Speed (rpm)__________Frequency (Hz):______[60] Altitude (m):_______[1000]Amb. Temp. (ºC)_______[40] Power factor:_____[0.8 or 1.0]Service factor: _____[1.0]Mounting:____[B3E]Installation: __________[inside or outside]Excitation:__________[brushless or with brushes] Excitation voltage (V)_____Starting: Full voltage [ ] Reduced voltage [ ] ______ %Operating conditions: [ ] Continuous frequency and voltage

[ ] Drive - from _______ to ______HzBearings:_____________[pedestal or on the endshield]Continuous or momentary thrust on bearings:___________Degree of Protection:__________ [Open - IP23S or enclosed - IP55]Cooling:______________ [air-air heat exchanger, air-water heat exchanger ...]Starting:___________[1 hot/2 cold]Starting torque:_______[40%] Synchronization torque (pull-in)____[30%]Synchronization pull-out torque (Pull out):_________[150%]Load inertia J (kgm2): __________ (Supply torque curve x load speed)Rotation direction:_______________[CW, CCW or both]Coupling (type):_______________WEG supply [ ] Yes [ ] NoMain motor dimensionsShaft height .. H:_______Total height: HD: _____________Distance between feet holes(longitudinal) .. B:______Distance between feet holes (transversal) .. A:_______Distance between feet hole and shaft shoulder .. C:____Shaft - Diameter .. ØD:_____ length .. E: ______

Key diameter ..GA: ________Key width ..F: _________

Main terminal box - Lead inlet: _________ [bottom]Cable gland _________________ [yes no]Number of terminals___________ [3 or 6]

Accessory terminal box:___________ [ Yes or no ]

Accessories - [ ] Space heater Voltage (V) ____________ [ ] Winding temperature detectors [PT100 with 3 wires - 1 per phase] [ ] Bearing temperature detectors [PT100 with 3 wires - 1 per bearing

Notes:__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

SYNCHRONOUS MOTOR SPECIFICATION (CHECK LIST)

16

WEGMÁQUINASAv. Pref. Waldemar Grubba,3000 - 89256-9000 - Jaraguá do Sul - SC

Phone: (47) 372-4000 - Fax: (47) 372-4030São Paulo - SP - Phone.: (11) 5053-2300 - Fax: (11) 5052-4202

www.weg.com.br

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WEG Synchronous Motors Technical Article English

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