Electric overhead crane specifications

Sl.No.SpecificationDescription1.Type Double Girder box type crane for indoor application2.Type of application In the sponge handling area where Zr fines (pyrophoric material) may be there.3.Class of duty:M5 as per IS 31774.Standards:The crane to be Designed, Manufactured and tested in accordance with the latest revisions & editions of IS 807, IS 3177and other relevant code and standards as indicated under Paragraph 5.05.LocationIndoor6.Capacity SWL10 Tonnes7.Height of track rail8.5 mtrs.8.Span22.74 mtrs9.Bay length 60.04 meter approximately10.Clearance height above the gantry rail2.5 mtrs.11.Cross travel of Crane20.74 mtrs.12.SpeedsHoisting / lowering 3.0 m/min (approximately ) with creep 0.3m/min by means of VFDCross travel 8.0 m /min( approximately) with creep 0.8 m/min by means of VFDLong Travel 20.0 m/min (approximately) with creep 2 m/min by means of VFD13.Bridge GirderDouble Girder Box type fabricated out of MS in one piece plateas per IS -2062. Girder should be strong and rugged to withstand the most severe combination of loads/stresses under different working conditions The bridge Girder shall be designed to have maximum deflection of span/1500 under 25% overload in order to have better structural integrity.Sufficient space shall be provided for ease of maintenance. Hand rail shall be provided on top of Cross Travel.Deflection and bending stress calculation to be submitted along with supply.Material –MS as per IS 206214.End carriageFabricated out of MS plates of suitable thickness to form box except for essential openings which should be reinforced. End carriages to be fitted with substantial safety stops to prevent the crane from falling and should not Interfere with removal of wheel.Suitable L type jacks to be provided at each end of end carriage for jacking up the crane while changing track wheels/ wheel maintenance and should not interfere with removal of wheel .15.Cross travel trolley frameTrolley frame to be made inone piece built up of rolled sections and plates to form a rigid structure capable of withstanding stresses .Top of trolley frame should be covered with plates all over except for openings required for Wire ropes, flexible cable for bottom block etc. Trolley frame to be fitted with substantial safety stops to prevent the same from falling. For parts placed on the trolley, access for maintenance, repair or replacement should be provided. Hand rails of suitable height should be provided on all four sides forsafety while carrying out maintenance work.

2Sl.No.SpecificationDescription16.Cross travel and Long travel wheelsShall be double flanged wheels of EN 8 material. The item should be machined and hardened to required hardness. It should be connected to LT assembly directly by means of gear wheel and in case of CT, the output shaft of the gear box shall be extended on either side and coupled to CT wheels. The wheels to be mounted on antifriction bearings and shall facilitate easy removal & replacement. Wheel assemblies should be removable type for ease of maintenance by providing bolting arrangement through suitable brackets.17.HookShall be Single shank “C“ type forged steel conforming to IS 15560 with spring loaded safety latch and mounted on thrust bearing for freely swivelling. 18.Wire ropeFibre core, 6x36 or 6x37 construction as per IS-2266 suitable for corrosive atmosphere. Diameter to be specified by supplier.19.Quality of steel for wire rope1770 KN as per IS-226620.No. of rope falls supporting theload421.Factor of safety for the wire rope622.Rope drumMachined out of seamless pipe of adequate thickness with machined grooves for the wire rope. The length/dia should be sufficient to wind the wire rope in one layer only when the drum is in the fully wound position. Drum shall be mounted on antifriction ball/ roller bearings. Rope drum edges of the crane shall be more than 5 times of the wire rope diameter so that rope does not come out during normal operation. 23.SheavesSheaves machined out of MS with adequate no of grooves to suit the no. of falls.24.Gear boxesAll gear boxes in the crane shall be rugged and totally enclosed in dustproof construction filled with oil. Straight or helical spur gear should be used for all motions (worm, bevel gears should not be used). All gears shall be of EN9 and pinions of EN-24 with suitable hardness, hardened with machine cut or hobbed teeth, metric module only. Gear box should be fabricated out of steel plates of minimum 8mm thickness. Top covers to be horizontal at each shaft centre line and fastened to the top half and can be removed for inspection and repair. The long travel mechanism shall be driven by two separate gearboxes at both ends of the span. All the extended shaft and end covers on gear box shall beprovided with good quality oil seal to prevent leakage. 25.CouplingGear couplings at all places.26.BearingsAntifriction type Ball/roller bearings of SKF/ FAG/ NTN / TIMKEN/ RHP (NSK) make. 27.BrakesHydraulic Thruster type brake for all operations with safety interlock for automatic operation on power failure.Double shoe brakes hinged type, brake drum of forged steel, completely machined. Brake levers, hinge pins etc shall be of hardened steel.Hoist shall be provided with two Hydraulic Thruster brakes.28.Limit switcha.All the limit switches on crane make shall be SIEMENS/ L&T/ CUTLER HAMMER of Heavy Duty type only.b.Gravity type limit switch should be provided above the Up limit switch to isolate the main power supply to the motor after its actuation. c.Two way lever type limit switch for CT/LT motions.

3Sl.No.SpecificationDescription29.WheelsDouble flanged crab / straight tread type made of EN8 material fitted with anti friction type bearings. They shall be mounted on a suitable housing for easy removal and maintenance. Details of housing to be specified by supplier. Grease Nipples shall be provided with closed end caps.No. of Wheels in a single side of rail: 4 Nos.Wheel to Wheel Distance (C/C):(i) Inner to Inner wheel : 3.0 m(ii) Inner to Outer wheel : 1.2 mWheel load: 50 KN maximum per wheel30.Motor Motors shall be totally enclosed, FLAMEPROOF, energy efficient, 150 starts per hour, 4/6 pole, 40% CDF 3 phase squirrel cage induction motors confirming to IS 325 having Class F or better insulation. Duty cycle of the motors shall be S4 or better. Single phase protection shall be provided for the motors. Motors shall be foot mounting. All motors shall be suitable for use of 415 V, 3 phase, 50 Hz AC supply, variable frequency drive operation & crane duty application. Capacity to be specified by supplier.The motors shall be of KIRLOSKAR / ABB / CG / SIEMENS / BHARAT BIJLEE / IEC/ L&T make.31.Control PanelMain control panel made out of MS sheet not less than 14SWG, duly powder coated with double door consisting of main contactor, LT, CT & hoist contactors of different current rating. The control Voltage should be 24V, A.C with interlock arrangement. All motions shall be operated through V.F.D. drive of suitable K.W. The make of VFD shall be L&T/ Siemens only. The Service Factor of the VFD shall be 115-120% of the Motor capacity. The VFD shall have input choke, line filter and incoming semi conductor fuses. The panel shall be FLAMEPROOF type with minimum IP54 protection. The Control panel shall have instrument cooling fan with panel filter. The control panel shall have panel light, space heaters and one spare 5/15A socket with MCB protections. 3 phase power indicators and drive ON/TRIP indicating lamps shall be mounted on the door. MCCB with E/F moduleshall be used for main incomer of the panel.32.Crane operationThe crane shall be operated through pendent push button station moving independently as well as through Radio Remote Operation. Operating frequency of Radio Remote Unit being supplied shall befurnished for approval before Manufacturing of the unit. Both the Radio remote & Pendent of the crane shall have mushroom type emergency push button.33.Cross travel power supplyThrough polycarbonate Drag Chain System. 34.Long travel power supplyPower tobe supplied to trolley through flexible festoon cable system with PVC clamping.35.Power supplyPower supply to motors, control circuit, lighting, hand lamp brakes etc shall be as per relevant standards through flexible PVC cables. The power cable shall beof CC /UNIVE RSAL /POL YCAB/ RP G/ FINEC AB/ GE M only and FRLS type. 36.Maintenance platformFull length maintenance platform shall be provided on both side of the guarders with hand railing and chequered plate flooring. Sufficient space should be provided on crane platform for ease of maintenance activity. 37.Inspection cageRepair cage should be provided on inside of end carriage for maintenance of the LT wheels.