Squirrel Cage Crane Duty Induction Motors - …

1 Squirrel cage Crane DutyInduction MotorsKDA Regal Electric presents KD series TEFC Squirrel cage Motors specifically designed forDOL operated Crane duty / intermittent duty application. The Motors are designed to take care ofthe high electrical and mechanical stresses arising due to frequent starts - stops associated withintermittent duty application. The Motors are compact providing high output for a given frame sizeand have low inertia. These salient features make them most suitable for EOT size KD71-KD355 LOutputRefer to Table 7 Standards & SpecificationKD series Motors generally conform to the followingstandards :IS:325 /IEC:60034-1 Three-phase Induction motorsIS:1231 /IS:2223 DimensionsIS.

2 4691 Degree of protectionThe Motors can also be offered as per IPSS & Operating ConditionsThese Motors can be wound for any voltages from 200 volts to 690 volts and for either 50Hz or 60 Hz KD Motors are available for supply voltage of 415V and frequency of supply voltage is assumed to be sinusoidal and balanced as defined in Motors are suitable for operation with variation in supply and site conditions as indicated in Table 1 AmbientAltitudeVoltageFrequencyCombinedV ariationVariationVariation45 C 1000m 10% 5%10%In the event of sustained operation at extreme limits of supply variation, the temperature rise may exceed by 10 C. Forother site conditions motor output should be adjusted as per Tables 2 & -2 Deration for High Ambient C50 C55 C60 C65 CClass B Temp.

3 Limit100%95%90%85%80%Class F Temp. limit100%100%100%95%85%3 Table - 3 Deration for AltitudeAltitude1500 m2000 m2500 m3000 m3500 mClass B Temp. Limit95%91%87%83%70%Class F Temp. Limit100%100%95%90%85%MountingStandard KD Motors are supplied with horizontal foot mounting ( IMB3 ) . However, Motors can be supplied with otheroptions like flange (IMB5/IMV1/IMV3) mounting / foot-cum-flange (IMB35)/face mounting (IMB14).Insulation and Temperature riseKD Motors are provided with Class F insulation and will operate satisfactorily in an ambient temperature range -20 Cto 45 C with class B temperature rise (75 C by resistance method) at nominal voltage / frequency and for altitude upto1000m above mean sea level.

4 Class H insulation may be supplied on Motors are generally used for intermittent duties like S2 /S3 / S4 & S5 associated with cyclic duration factor (CDF)and no. of starts per hour, as defined in IS Cyclic Duration Factor is defined as follows :Period energised% CDF = ---------------------------------------- ---X 100 Duration of complete duty cycleThe descriptive details of various duties associated with intermittent /craneduty application experienced by KD Motors are as follows :S2 duty ( Shot time duty )Operation at constant load duringa given time, less than that requiredto reach thermal equilibrium,followed by a rest and de-energized period of sufficientduration to re-establish machinetemperatures within 2 C of thecoolant (see Fig.)

5 1).The recommended values for theshort-time duty are 10, 30,60 and90 minutesS3 duty ( Intermittent duty )A sequence of identical duty cycles, each including a period of operation atconstant load and a rest and de-energized period. These periods being tooshort to attain thermal equilibrium during one duty cycle (see ). In thisduty, the cycle is such that the starting current does not significantly affectthe temperature rise for this duty otherwise specified the periodic duty is applicable for 10 minutesduration. The S3 duty generally is associated with 6 starts per Operation at constant loadR= At rest and de-gized max= Maximum temperature attained during the dutycycleNCyclic duration factor = x 100%N + R maxELECTRICLOSSESTEMPLOADNRPERIOD OFONE CYCLETIMEF igure 2 Intermittent periodic duty S3 TIMETEMPELECTRICLOSSESLOADN maxN= Operation at constant load max= Maximum temperature attained during the dutycycleFigure 1 Short time duty S24S4 duty (Intermittent duty with Starting )A sequence of identical duty cycles, each cycle includinga significant period of starting, a period of operation atconstant load and a rest and de-energized period.

6 Theseperiods being too short to attain thermal equilibrium duringone duty cycle (see ). motor is stopped either naturally or by means of mechanicalbrake so that there is no cause of extra duty (Intermittent duty with ElectricalBraking )A sequence of identical duty cycles, each cycle consistingof a period of starting, a period of operation at constantload, a period of rapid electric braking and rest and de-energized period. The operating and rest and de-energizedperiods being too short to attain thermal equilibrium duringone duty cycle (see ).Constructional FeaturesFrameThe stator frames in general are made of rugged cast iron with integral cast feet in case of foot mounted Motors . Maximumcooling surface is obtained by quadrangular disposition of cooling ribs.

7 (See Fig. 6)End bracketRibbed end brackets are provided from frame KD160 upwards. For frame sizes upto KD225S, single piece end bracketis eliminating outer bearing frame sizes KD200L and above, unique feature of grease relief arrangement facilitating on-line re-greasing isprovided. (See Fig. 5)Figure 4 Intermittent periodic duty with ElectricBraking S5D =StartingN = Operation at constant loadF=Electric brkingR = At rest and de-gized max=Maximum temperature attained during the duty cycleD + N + FCyclic duration factor = x 100%D + N + F + R maxELECTRICLOSSESTEMPLOADPERIOD OFONE CYCLENDRFTIMEF igure 3 Intermittent periodic duty with starting S4D = StartingN = Operation at constant loadR = At rest and de-energized max= Maximum temperature attained during the duty cycleD + NCyclic duration factor = x 100%D + N + RTIMETEMP maxELECTRICLOSSESLOADPERIOD OFONE CYCLEDNRW hile specifying duty cycle for S3 duty % CDF is to be specified and for S4/S5 duties % CDF and no.

8 Of starts perhour, is to be KD Motors have single cylindrical shaft extension. However, double cylindrical shaft extension or tapered shaftextension ( single / double ) can be offered on boxThe terminal box position of all the Motors are on RHS when viewed from the driving end except for KD71 frame &KD112M frames. The terminal box position for these frames are on TOP box for all the Motors can be rotated in steps of 90 through 360 there by providing four alternative directionof cable sizes for standard terminal box arrangement are given in Table 4 .Table - 4 FRAME SIZE STUD SIZE MAX. CABLE SIZE DOWELL S CAT. NOFrame sizeStud sizeMax. Cable sizeDowell's Cat. 90 M5 1 NO. 3C X 4 mm CUS/06100 132 M6 1 NO.

9 3C X 6 mm CUS/07M6 1 NO. 3C X 35 mm CUS/11160 - 180 M6 1 NO. 3C X 50 mm CUS/13200 - 225 M12 1 NO. 3C X 70 mm CUS/18250 - 280 M12 1 NO. 3C X 185 mm CUS/25, 20315 M12 2 NO. 3C X 185 mm CUS/29M12 1 NO. 3C X 300 mm CUS/29355 M12/M16 2 NOS. 3C X 300 mm CUS/27 BearingsMetric size ball / roller bearings with C3 clearance are used in horizontal foot mounted Motors . For frame sizes uptoKD315L, ball bearings are used at both ends whereas for frame size KD355 roller / ball bearings are used on DE/NDEside respectively. Bearing size for Motors with single shaft extension are as per Table 5. Double shielded bearings areused upto frame 180. These bearings are prelubricated and does not allow relubrication. Grease used for Motors offrame 200 onward is Alithex 20 or equivalent [Lithium based grade 2]Fig.

10 5 Fig. 66 Table 5 Bearing DataFRAMEHORIZONTAL MOUNTING VERTICAL MOUNTINGSIZE POLES DRIVE END NON-DRIVE END DRIVE END NON-DRIVE END71 ALL 6203ZZ C3 6203ZZ C3 6203ZZ C3 6203ZZ C380 ALL 6204ZZ C3 6204ZZ C3 6204ZZ C3 6204ZZ C390 ALL 6205ZZ C3 6204ZZ C3 6205ZZ C3 6204ZZ C3100 ALL 6206ZZ C3 6205ZZ C3 6206ZZ C3 6205ZZ C3112 ALL 6206ZZ C3 6205ZZ C3 6206ZZ C3 6205ZZ C3132 ALL 6208ZZ C3 6207ZZ C3 6208ZZ C3 6207ZZ C3160 ALL 6309ZZ C3 6209ZZ C3 6309ZZ C3 6209ZZ C3180 ALL 6310ZZ C3 6210ZZ C3 6310ZZ C3 6210ZZ C3200 ALL 6312 C3 6310ZZ C3 6312 C3 6310ZZ C3225 S ALL 6313 C3 6312 C3 6313 C3 6312 C3225 M ALL 6313 C3 6313 C3 6313 C3 6313 C3250 ALL 6314 C3 6313 C3 6314 C3 6313 C3280 ALL 6317 C3 6314 C3 6317 C3 6317 C3315 S/M1