SPEC. NO. COFMOW/ICF/T-1/02
PURPOSE FOR WHICH REQUIRED AND CAPABILITY:
1.1 The Robotic/Automatic Spot Welding machine with spot welding fixtures for manufacturing of sidewalls and roofs of Railway Coaches is required for assembly and fabrication through Resistance Spot Welding Technique. The equipment should be configured to enable it to produce the Body sidewall as per details in Annexure-I of schedule-I, which can withstand in-service forces and abnormal impact loads. The machine shall be designed as per Parameters given in Schedule-I.
1.2.1 The machine shall be capable of assembling Body sidewall and Lavatory sidewall (curved and straight) complete as indicated in Annexure-I of schedule-I with suitable fixtures and carrying out High quality spot-welding work, on any desired plane, with consistent quality using different work piece thickness of metal of different chemical compositions/ combinations as follows:
RDSO Spec.CK201X2 Cr 12
RDSO Spec.CK201X5 Cr Ni 18 10
The machine should be able to spot weld-coated components such as body pillar, stiffeners etc. with sidewall sheet and various roof arch, stiffeners with roof sheet..
The sub-assemblies as mentioned above shall be fabricated (tack welded) in fixture and shall be loaded over spot welding fixture to move to the next station for spot welding. However the tenderers should elaborate the procedure/conditions etc. if any required prior to spot-welding on the machine offered by them.
Robotic/Automatic Rail Coach Side wall Spot Welding work station should meet the performance and testing criteria laid down in international specifications and norms followed such as issued by RWMA (Resistance Welders Manufacturers Association) and so on.
The Machine must be capable of generation of spot welds (nuggets) between faying parts/components as per relevant drawings to a high dimensional tolerance as well as high degree of repeatability and also exceptionally high weld integrity with low thermal and/or mechanical distortion and without any other surface abnormality. The process requirement for spot-weld is indicated in Annexure-II of schedule-I.
The tenderers shall specifically confirm conformance to the relevant safety class in their offers as per International Standards/ Norms such as AWS, DVS etc.
A set of input/output chart for the machine for different type of coaches (7 nos.) is enclosed as annexure - E for guidance. Full set of input/output charts will be made available to the successful bidder.
Criteria of Acceptance:
The machine should be able to complete spot welding of a minimum of one coach consisting of two side walls (full set including LH & RH) including lavatory sidewalls and one roof SCN type coach per day of 2 shifts of 8.0 hrs each (with average availability of 85%).
The cycle time (floor to floor timing) for complete tack welding and spot welding of sidewalls on batch production basis should be furnished separately in the offer by the Bidder. The cycle time should include the various elements involved as given below, in accordance with the suggested sequence of operation as given in 1.2.3 above.
Loading/unloading time required for each subassembly inclusive of fixturing etc.
Set up time of the machine before starting of spot welding operation.
Checking / measurement time, if any.
Spot-welding time, for each spot.
Total spot welding time for each complete sub-assembly.
Total time for one coach set.
The Productivity calculation in detail should be furnished.
The machine manufacturer shall be required to demonstrate productivity parameters during commissioning/testing performance of the machine at ICF/Chennai.
The uptime of the machine shall be of minimum 85% measured every week during the entire proving out period (from the date of commissioning) of machine and 85% measured every month till the warranty expires. The supplier may continuously monitor and guide the operations during entire proving out period.
1.5 Quality Criteria:
1.5.1 The strength of the spot welded connection is a major requirement; the spot welded connection between sheeting and the frame of the coach is part of the structural strength calculation. With the peel test it has to be proved that the nugget has the required diameter. Peel testing should prove the required strength. Please also refer Annexure-C.
Another important requirement is the visual appearance of the surface. The electrodes have to be shaped in a way that the welding spot can hardly be seen on the visible surface of the car body/coach shell.
The machine should have mechanism to ensure quality of spots irrespective of minor thickness variations in the joining sheet metal. It should be either self-corrective or indicative (prompting the correction) type.
The shape of the nugget should be regular and without undue stress Concentrations i.e. without improper notch cavity.
Scope of supply:
2.1 The scope covers the following:
2.1.1 Design, manufacture, supply, commissioning and proving out on turnkey basis for the complete machine and related equipments for making it fully functional including safety/hazards prevention fittings/ Interlocks etc.) as follows:
Robotic/Automatic Rail Coach Side wall spot welding system with / without gantry. (Nos. of robot required to be decided by the supplier, based on production requirement.)
Spot welding fixture for Body sidewall and Lavatory sidewalls.
Offline program of coaches mentioned in Annexure-I of schedule-I to technical specification.
The turnkey work shall include all civil engineering, electrical and other works necessary for installation and commissioning of machine.
For basic design features refer to Schedule-III, for general electrical equipment design refer to Schedule-II to technical specification and for CNC system refer to schedule IV to technical specification. The supply shall include all concomitant accessories/equipments and spares, training as detailed in specification.
The concomitant accessories should include the following in addition to any other accessory for satisfactory performance of the machine: -
CNC Control system.
Battery back up facility for memory retention during power failure.
Heat exchanger (water cooled / oil cooled).
First fill of lubricating oil, hydraulic oil and grease etc. for initial commissioning of machine till the machine is taken over after PAT.
Kick less cable for operation of the spot welding system.
Air conditioning system for CNC control as well as electrical panel cabinet.
Standard set of maintenance tools for Robot, Spot Welding guns, Fixtures, Robot Gantry etc. (Three Sets: One set for Machine operator, One set for Mechanical maintenance and One set for Electrical/Electronic maintenance).
Electrode tips for manufacturing 90 coach sets, indicating the quantity, description and details of Indigenous suppliers.
Microprocessor based welding controller.
The chiller unit of adequate capacity for cooling of transformer, welding gun etc.
Voltage stabilizer for the complete machine.
Set of spot welding guns required for manufacturing assemblies mentioned in Annexure–I to Sch.-I to technical specification.
Complete set of Tack welding Flexi-Fixture and Spot Welding Flexi-Fixture for manufacturing all components as per drawings mentioned in the Annexure–I to Sch.-I to technical specification. Drawings for all the fixtures should be supplied as a part of concomitant accessories.
Remote operated switching panel and compatible connectors.
In case Bidder desires to suggest any accessories to achieve higher production rates and / or better quality levels, the same shall be explicitly explained and quote the price separately as Optional accessories.
Consumables for one Year like tips etc.
Accessories for automatic tip re-grinding.
Off line programming workstation for working on CAD software, programming software, necessary hardware for connecting the work station to the welding plant for down loading the programmes.
Supply of Hydraulic/Lubrication Oils:
The bidder shall provide the initial fill along with machine and additional quantity required till the machine is taken over after PAT for:-
a) Mounting lubricant
b) Hydraulic oil
c) Lubrication oil
Also, the bidder should indicate the quantity and brand name of oils used and their Indian equivalent brand name, grade, specification and price.
3. Design Features:
3.1 General Characteristics:
The general characteristics of the machine shall be as per Schedule-III to technical specification.
Machine with two working station i.e. two universal fixture with following design characteristics:
Robotic Spot welding machine with Moving gantry, having 8 minimum Axes movement with automatic spot welding Gun changer and assembly fixtures for Body sidewall, Lavatory sidewall and roof.
-Longitudinal travel (X Axis)
-Cross travel (Y Axis)
-Vertical travel (Z Axis)
Lifting capacity of welding Manipulator /Robot
To be indicated by the manufacturer
Average Welding time (from spot to spot)
Electrode pressure/ welding force range
Set of Welding Guns
Firm should quote & supply set of welding guns with adequate throat gap, approach stroke and welding stroke adjustable in step less manner for manufacturing sub assemblies as listed out in Annexure-I of schedule-I to technical specification.
c) Each spot welding fixture should be capable of spot welding straight profiled sidewalls as per Annexure-I to Sch-I to technical specification.
d) Special Tackles for handling spot welded sidewall to be properly designed and separately supplied to use with existing EOT crane.
Supplier must indicate any other item not covered above for manufacture of sub-assemblies listed in Annexure-I of schedule-I to technical specification.
As far as possible, special fixtures should be of flexible type to minimize the changeover time and the variety of fixtures.
General arrangement of the Machine:
The spot welding station shall consist of Robot / Automatic system moving in such a manner to access the entire length and width of the components as listed in Annexure-I to Schedule-I to technical specification, fully automatic with a base stroke of 40mtrs in longitudinal direction. The spot welding Robot/Robots should have a carrying capacity of spot welding gun. The spot welding robot shall be able to mount a particular spot welding gun as per the requirement from the set of welding guns with different throat gaps available in the cabinet (magazine).
For achieving better productivity “Twin spot assembly or Twin gun” (i.e. two electrodes or guns working simultaneously) can be considered. The pitch between the electrodes shall be adjustable. There shall be provision for operating single electrode also.
The change of guns shall be fully automatic controlled through CNC. All the associated equipment necessary for the spot welding operations should be located at convenient place close to the workstation. With manipulation of set of welding guns, all the locations of the sub-assemblies shall be approached for carrying out automatic spot welding operation. The work area shall have a flexible Spot welding fixture designed to receive sidewall with the help of EOT crane after tack welding.
The job/works pieces to be spot-welded must be clamped tightly together pneumatically or by suitable clamping arrangement at the weld location to enable the passage of welding current. It should be possible to regulate the electrode force in order to achieve required coordination for production of satisfactory spot-weld nugget. Thus the design of the machine should cater to a coordinated application of electric current and mechanical pressure of proper magnitude and durations. Also it should be possible to vary the magnitude of current and electrodes force if required separately/independently. The welding current must pass from the electrode through the fabrication work/job, its continuity being assured by forces applied by the electrodes which are so shaped to provide the necessary current density and pressure in addition to physical access to the location of intended spot weld. The sequence of operation must first develop proper contact and sufficient heat to raise a confined volume of metal to the molten state (Nugget initiation). This metal then cools while under pressure until it has adequate strength (equal to strength of base metal) to hold the part together. The current density and pressure must be such that a nugget is formed but not so high that the molten metal is expelled from the weld zone. The time of current flow (weld time) must be sufficiently short to prevent excessive heating of electrode faces and to prevent bonding and minimize electrode wear/damage. All the weld parameters should be controlled by latest software throughout the weld cycle with a graphic display and manual override facility for sample testing of nuggets, if feasible. The software should have the facility for detailing all the different parameter changes in due course of welding the sub assembly, preferably in print out form.
Machine design should cater to controlled rate of heat generation such that weld of required and adequate strength i.e. practically the strength of the base metal will be produced without excessive electrode heating/rapid deterioration and/or extension or Heat Affected Zone far into the base metal/sheeting material. The Bidders shall furnish complete details in respect of the features, which ensure production of spot welds of high quality specifically confirming conformance with international standards /norms /specification in their offers.
The spot weld/nugget generation should be absolutely without weld metal expulsion and/or splash, cavitations, spitting, electrode indentation, weld cracking and without lowering of mechanical strength properties etc.
The machine shall be robust, rigid and of sturdy construction. It shall be designed to meet heavy-duty demands of various operations on the machine under normal workshop environment for such machines. The climatic conditions at ICF/Chennai may be taken as 18°C (minimum) 50°C (Maximum) temperature and humidity 95%(maximum) with dusty environment conditions. Therefore, the Air condition system for CNC controls has to be of adequate capacity for trouble-free Operation. The changes in ambient temperature conditions shall not affect the performance of the machine.
The machine offered should be free from vibrations and operational noise at the operators location shall be within 75 db even when working at full capacity on sustained two shift working.
The machine frame structure should be fabricated out of high quality structural steel plates. Crack detection test to be carried out at all critical weld joints and relevant test certificate to be produced. The structure should be stress relieved prior to machining to prevent any subsequent distortion.
The machine configuration should be broadly as under:
The bidder may indicate the number of robots/ Automatic system included in the offer to achieve the specified capability and productivity.
The system should have the following features:-
Automatic tool changer mounted in the centre for accessing spot welding gun, grippers and electrical or pneumatic tools etc.
Free movement of the robot/robots / Automatic system to reach all corners of the sub-assemblies.
Anti Collision feature for the robots to prevent damage to the equipment. Software should automatically monitor and indicate if robots are likely to collide when a robot program is executed.
The software should have facility for the Robot program to be downloaded to the real system without any translation.
Following features should be available in the Robotic/Automatic Rail Coach Side wall spot welding system:-
Full working range of the robot can be utilized.
Simulation and off-line programming is possible.
Integrated tool changer is available.
The arms are mechanically balanced and equipped with double bearings.
Advanced motion control and collision detection feature.
Tool changing to be handled automatically by the robot within the working area.
All movements are programmed from the robot teach pendant, ensuring smooth and simpler operation.
Provision for trouble shooting & software updates through internet connection.
A set of guns of adequate throat depth and gap should be provided as per capability and productivity requirements. The size and shape of the guns should be designed to cover all the spots on the job.
The electrics consisting of welding transformer, kickless cables, welding electrodes, electronic power devices, control panels etc., shall be of adequate capacity to meet the welding requirement indicated without getting over loaded/over heated to work at ambient temperature and conditions specified.
The control equipment shall be microprocessor/ micro controller based. Setting of the welding parameters namely, weld time, squeeze time, hold time etc., shall be possible both manually and through programming.
Spot Welding Power Source:
The machine shall incorporate welding transformer (Three phase) as a power source of adequate capacity with safety factor considering the maximum load that is likely subjected to with the machine working at its full capacity at an ambient temperature of 50 deg C. The power source shall be able to perform spot welding operation of high quality spot welds conforming to latest National/ International standards. The insulation shall be class “F” or above. The power source shall employ IGBT and it shall be possible to set the welding current in step less manner, both manually and through programming. Provision shall be made to select either auto mode (through Programme) / manual mode with necessary safety interlocks.
The transformer design and capacity must meet the requirement of multi-spot welding operations in quick succession without any adverse effect on generation/formation of proper weld nuggets.
In case of water-cooled transformer provision shall be made for protection of the transformer against water supply failure for both windings.
The machine should be supplied with closed circuit coolant system.
The transformer secondary, top and bottom bus bars, electrode holders, welding electrode, diode and IGBT shall be water cooled and shall be provided with individual circuits and flow adjustment valves and should be leak proof.
The water outlets of all sub-circuits shall be neatly brought out and visibly drained out through a collecting funnel arrangement.
Suitable coolant system with pump, motor tank, filter etc. shall be provided. The coolant pump shall be as per IS: 2161-1962. The filter shall be of reusable type and indigenously available. If reusable filter cannot be offered, adequate no. of filters for 2 years working on double shift basis shall be offered as spare. If reusable filters can not be offered, the filter cartridge shall be readily available in India.
Welding Gun and Electrode:
The welding Gun design should be exceptionally rigid, rugged and capable of withstanding high application forces to perform spot welding operation in a reliable and efficient manner. Practically Gun should be deflection free under pressure transmission through its body.
The Bidder should give the following details: -
Life of electrode in double shift working with the specified production level.
Method of repair (In House).
Instruments / Tools required for repair.
The Electrodes must have good electrical conductivity besides adequate strength and hardness to resist the deformations caused by the repeated applications of high electrode forces.
CNC system including welding controls:
The Machine shall incorporate a CNC system of reputed makes like Siemens, Fanuc etc. customized to carry out all control functions stated in the specification. It should have features as indicated in schedule-IV to technical specification.
Utilities available with ICF:
Electricity as available.
Compressed air and water as available.
The whole spot welding machine shall be designed to operate with 415V ± 10%, 50 cycles ± 3%. Three phase three wire system with neutral solidly earthed at the source.
The electrical supply shall be made available by ICF only at one point through an electrical isolating equipment (like fuse, switch unit Air Circuit Breaker etc) provided by ICF in the vicinity of the Plant.
The existing electrical distribution system also feeds other machine tools, including those employing power devices working on switching mode, resulting in the increase of waveform distortion. The maximum total harmonic distortion is 15%.
The total cabling work from the isolation switch to the Plant shall be carried out by the tenderer. The wiring shall conform to IS 732 (latest). All the internal wiring cables i.e., for the equipment supplied, both for power and control wiring shall be included in the scope of work. This includes the electrical panels/distribution boards for the sub-distribution of the power by various equipment.
The bidder shall indicate total power requirement.
All other electrical/electronic items shall be as per Schedule - II.
Spares and Consumables:
Perishable and non-perishable spares required for normal maintenance for two years to cover complete range of mechanical, hydraulic, electrical and electronics equipments including control should be supplied.
The tenderer shall confirm that all spares and consumables required for the operation of the machine will be available easily on a long-term basis preferably for a minimum of 10 years.
Special features incorporated into the machine, if any, shall be indicated separately by the tenderer, clearly indicating the advantages of these features.
7.1 The tenderer should certify that the machine offered fully meets the Specifications. Various design features incorporated in the machine to Fulfill different technical performance requirement shall be fully explained in the offer. However, minor deviations from these specification which do not affect or in any way interfere with the stipulated performance standards or would result in improved reliability or would reduce recurring maintenance/operating cost of the machine can be considered for acceptance.
Inspection of Equipment & Testing at Manufacturer’s Works:
Capability of the machine shall be demonstrated to the satisfaction of inspecting officer.
Manufacturer must have suitable facilities at their works for carrying out various performance tests on the machine.
A sample inspection chart for inspecting the machine should be supplied along with the bid. The inspection charts should indicate all the tests that are carried out during the machine manufacture.
The Bidder will submit quality assurance plan being followed at the manufacturers works for ensuring quality of the products offered.
Proving out at Manufacturer’s works:
The system shall be proved out for establishing the claimed productivity mentioned in clause 1.3.1 on one segment each of LHB coach sidewall of 18 mtrs. (approx), lavatory sidewall of 2 mtrs. And one roof at the inspection stage itself at manufacturer’s premises as per drawings.
As per the provisions made in the tender document.
10.1 The Bidder shall execute Foundation of machine on a Turn –Key Basis for which scope should include:
Design of necessary foundation for the Robotic Spot welding machine along with associate equipment / accessories.
Execution of foundation at the clear site provided by ICF
Erection of machine at the site after completion of Foundation.
10.2 The Bidder shall furnish within 3 months of issue of LOA to the consignee 3 copies of foundation drawings and related diagram (Mechanical & Electrical), giving machine weight, overall dimension, foundation detail, electrical load and circuitry, to enable site readiness for installation and commissioning of the machine and other equipments on receipt.
Note:- The foundation should be made ready well in time, so that the machine / equipment on receipt does not remain idle for the foundation.
11 Turnkey Contract for Installation and Commissioning:
11.1 The manufacturer or his authorized contractor shall arrange commissioning of the machine after installation is done under the supervision of manufacturer’s experts. The contractor or his agent would be required to inspect the consignment at the consignee’s end before unpacking is done and carry out a joint check of the receipt of components to avoid subsequent complaints regarding short shipment or transit damages.
The contract shall be awarded on turnkey basis and the scope of turn key shall include the following works
Unloading the consignment and movement to site.
Installation and erection.
All electrical works including cabling from mains and earthing. All cabling shall be accommodated in suitable trenches with waterproof covers enabling easy access for maintenance.
All civil engineering works connected with installation and erection excluding flooring and overhead shed.
The supplier or his agent shall install and commission the system within 120 days from the date of receipt of consignment at site.
The machine shall be proved out to demonstrate the productivity at purchaser’s premises.
The consignee shall be responsible for:
Provision of a clear covered site for construction of foundation as per the schedule given by the supplier to ensure its readiness before arrival of machine at site.
Electricity, water and compressed air free of cost.
In case a road mobile crane has to be arranged by the supplier for material handling, a clear approach for it up to the site has to be provided.
Space for storage of material/equipment required for working/construction of foundation and installation of machine etc.
The supplier shall be responsible for:
Design of the foundation keeping in view the soil conditions at site.
Advise consignee in time regarding schedule for requirement of clear site for construction of foundation and other infrastructure.
Construction of the foundation before arrival of machine at site.
Installation and commissioning of the machine including arrangement of all man power, material, material handling equipment and facilities required for the same.
The machine will be deemed to be commissioned once the timing established at manufacturers works (duly certified by the nominated inspector), are established at the consignee works as laid down in cl. 1.3.1 for two coach set of GS side wall subassemblies as laid down in acceptance criteria. The proving out trials for balance coaches shall be carried out for issuance of PTC.
The contractor or his agent shall demonstrate the machine performance after successful commissioning at the consignee’s works for 25 coach sets consisting of all type of coaches as listed in Annexure-I to Schedule-I to technical specification within one month time. In case all type of coaches are not available within this period the proving out of balance coaches will be done by ICF themselves. The machine performance shall be watched by the consignee for a period of one (1) month before the final proving test certificate is issued. The PTC should not be held up for want of availability of some type of coaches.
If an assembly/sub assembly is required to be taken back to the manufacturer's premises for repairs/replacement either before commissioning or during warranty, the manufacturer or his agent would be required to submit an Indemnity Bond. In case the entire machine has to be taken back, a Bank Guarantee would have to be submitted. The Indemnity Bond/Bank Guarantee shall be of adequate value so as to cover the cost of the assembly/sub assembly/paid up cost of the machine.
12.1 The tenderer should provide satisfactory evidence, to show that machine is from a reputed manufacturer who has experience in manufacturing & supply of similar Robotic spot welding machine.
13.1 All steel surfaces shall be thoroughly cleaned by disc grinding/sanding or shot/sand blasting and then immediately painted (except mechanical mating surfaces) with two coats of red oxide-zinc chromate primer as per IS: 2074. All weld joints shall be cleaned of slag and spatters before painting. The paint surfaces of bought out items shall not be disturbed generally.
The machine/equipment accessories shall be painted with two coats of synthetic enamel paint in apple green colour, Number 281 to IS: 5-1978 (if any specific colour and code standardized by BIS is in vogue, the same should be mentioned by the bidder). The total dry film thickness on the steel surfaces shall be about 100 microns.
Acceptable makes of the machine :
1. M/s.Bissiach & Caru Spa Italy.
C-671, New Friends Colony
New Delhi – 110 065.
Phone : 011-41626898 , (M) 9810041965
2. M/s.IGM Roboter Systems AG
2335 Wiener – Nendorf Austria
Phone : (M) 0139-11591273
Indian Agents :
M/s.IGM Robotic Systems India Pvt.Ltd.
A/301-302 Dimple Arcade Annexe
Asha Nagar, Kandivali (East)
3. M/s. Rhythmsoft Robotics & Automation Pvt.Ltd., Nashik
SPECIFICATION OF ROBOTIC SPOT WELDING MACHINE (FOR SIDE WALL ASSEMBLIES)
Spot Welding Capacity
1. Up to total 6.3mm thick, with various stainless steel sheet combinations.
2. Up to total 6.3mm thick with low alloy steel having Max.0.3% Carbon combinations).
Sheet Material to be spot-welded.
As per RDSO spec. no. CK201 x 2 Cr12 and
CK 201 X 5 Cr Ni 18 10
Regarding nugget diameter for different materials/sheet thickness, refer Annexure-C.
Robotic spot welding machine effective travel:
-Longitudinal travel (X Axis)
-Cross travel (Y Axis)
-Vertical travel (Z Axis)
+/- 0.3 mm or better. Provision for measuring inters spot distance/pitch to be furnished.
ANNEXURE –I to Schedule-I
1 List of sidewalls to be spot-welded
2 Confidentiality & secrecy requirements:
These drawing being confidential documents shall not be disclosed or published to third party in India or abroad without the prior written permission of Integral Coach Factory (I.R) and shall not be used for any other purpose except for study of the job requirements viz-a-viz machine specification /proposal being considered by the machine manufacture/supplier."
Regarding secrecy provisions please refer to General Conditions of Contract clauses pertaining to Official Secrets Act (Govt. of India).
ANNEXURE –II to Schedule-I
The bidder should quote the values for spot welding of following combination.
RDSO Spec. no.CK 201 X2 Cr 12
RDSO Spec. no.CK 201 X5 Cr Ni 18 10
GENERAL SPECIFICATION (ELECTRICAL)
All equipments and material shall comply with appropriate Indian Standards (latest) or National Standards of the country of origin provided the latter are equivalent to do better than the former. For items for which Indian Standards are not published, National Standards shall be acceptable. The tenderer shall indicate the Standards applicable.
The following standards are applicable in particular.
(Corresponding International Standards like ASA, NEMA, BSS, DIN etc. may also be quoted).
IS : 325-1979 (latest) - Three phase induction motors (corresponding to IEC pub-34-1) (Latest).
IS : 1248 (Latest) - Direct acting indicating analogue electrical measuring instruments and their accessories (corresponding to IEC Pub-51) (Latest).
IS : 1231-1974 (Latest) - Dimensions of three phase induction motors (corresponding to IEC Pub-72-1) Latest).
IS : 1271-1985 (Latest) - Classification of insulation material for electrical machinery & apparatus in elation to their thermal stability in service (corresponding to IEC-Pub-85) (Latest).
IS : 6875 (Latest) - Push Buttons and related control switches corresponding to IEC Pub/73) (Latest).
IS : 375-1963 (Latest) - Marking and arrangement of switch gear, bus bars, main connection & auxiliary wiring.
IS : 996-1979 (Latest) - Single phase small AC and universal electrical motors.
IS : 1356 (Latest) - Electrical equipment of machine tools.
IS : 2516 (Latest) - Circuit breakers (corresponding to IEC Pub-56) (Latest)
3. Unless specified in the main specification, the AC motors and starters shall be of the following type. Tenderer is, however, free to give alternative proposal along with justification, if in his view alternative proposal in warranted by site conditions.
TYPE OF MOTOR
TYPE OF STARTER
Any type of AC motor starting current of which does not exceed 75 amps.
Direct on line
AC squirrel cage, introduction motors, starting current of which is above 75 amps. if started direct on line.
Star delta or Auto transformer type
AC slipring type motor
Resistance type air/fan cooled
AC synchronous or synchronous induction motor.
Suitable makers standard.
Resistance type/Thyristor type
4. The control gear for AC/DC motors shall incorporate the following protection devices as concomitant accessories.
4.1 No Voltage Protection - No voltage protection shall be provided so that machine will not start up again by itself when, following an interruption the supply is restored.
4.2 Short Circuit Protection - To protect against short circuits due to insulation failure of faulty connections HRC fuses shall be provided for each motor. The rating of the fuse shall be such as to take care of the over current due to motor starting.
4.3 Over Load Protection - To prevent motors from overloading, overload protection shall be provided separately for each motor. Three phase motors shall be protected by overload tripping devices on each phase.
4.4 Single Phasing Protection - A separate current sensitive delayed action single phasing preventor shall be provided for each motor separately. Overload protection shall not be treated as single phasing preventor.
5. Control equipment shall be mounted in separate drip proof enclosures. Control enclosures and compartments are to be so designed as to give adequate protection against ingress of dust, oil, coolant or chips. All control devices like contractors etc. shall be front mounted on a rigidly fabricated metal panel for ease of operation. All other electrics shall be installed that they are readily accessible when the doors and covers are opened. Hinged covers shall be interlocked with the machine tool control to prevent operation of the machine when cover is open.
6. The motor shall be totally enclosed with or without fan cooled frame. Screen protected drip proof type motor may be provided if it is mounted inside protective enclosures.
7. The electrical equipments shall comply with the requirement of Indian Electricity Act and Rules.
8. All instruments shall be of the Industrial Grade “A” (IS-1248) switch board type the range of the instrument shall be such that the maximum load expected in the circuit shall produce a deflection of 60% to 80% of the full scale.
9. The supplier shall furnish 3 sets of complete electrical and electronic wiring diagrams in full details to enable the maintenance staff to locate faults in the circuits, 3 sets of part catalogues, maintenance manuals operating instructions with details of coils and windings, used in the equipment to facilitate repairs and maintenance should also be supplied.
10. For main motor class “B” insulation shall be provided. If any other class of insulation is proposed, detailed justification for providing different class of insulation shall be given.
11. Motors shall be designed to withstand frequent starts, stops and reversals as demanded in the operation of the machine.
12. Two earthing terminals shall be provided on all electric motors including the control gear.
13. POWER SUPPLY
13.1 The machine shall be suitable for operation on 415 volts 3 phase 50 cycles AC 3 wire or 4 wire system with neutral solidity earthed. The supply voltage may very upto + 10%. The frequency may vary upto + 3%. However, full rated power of the motor shall be available at the lower voltage. Voltage stabiliser as specified against clause 13.2 below shall not be required for machine having electrical motor power requirement upto 30 KW.
13.2 In case of machine not equipped with NC, CNC and thyristor controlled devices a suitable servo controlled voltage stabiliser of adequate capacity to cater for entire electrical load of the machine having electrical load requirement exceeding 30 KW shall be offered along with machine as a concomitant accessory. Voltage stabiliser from reputed sources, subject to confirmation by COFMOW, are acceptable. The voltage stabiliser shall conform to:
i) Input voltage - 20 to 460 volts 3 phase 4 wire unbalanced supply.
ii) Output voltage - 415 volts
iii) Regulation - + 1% from No load to Full load.
iv) Rate of correction - 20 volts per second per phase.
v) Wave from distortion - NIL
vi) Efficiency - Not less than 97%.
vii) Winding and class of insulation - Copper wire wound with “B” class of insulation or better.
13.3 In case of machines equipped with NC,ss CNC, Thyristor controlled devices and other sophisticated electronic gadgets including microprocessors etc. which are susceptible to power line spikes and surges, a suitable voltage stabilizer and ultra isolation transformer of adequate capacity to cover for the entire electrical load of the machine shall be offered as a concomitant accessory conforming to Specification for voltage stabilizer as mentioned in clause 13.2 above and isolation transformer to the parameters mentioned below. Indigenous make voltage stabilizer and isolation transformer from the reputed manufacturers are acceptable.
i) Transformer ratio - 1:1
ii) Winding - Copper wire wound with “B” class insulation or better.
iii) Protection - To arrest spikes and surges to the order of 3 KV for 200-400 micro seconds duration.
iv) Common mode noise rejection - 120 dB
v) Isolation - Capacitance 005 Pf: resistance greater than 1000 Mega Ohms.
13.4 Voltage stabiliser shall be equipped with a protective relay to trip to trip the AC power supply to the machine instantaneously with audio and visual indication to the operator. Settings of the protective relay for low and high voltage shall be 320 volts and 460 volts respectively. Protective relay shall be provided as concomitant accessory on the machines having electrical load below 30 KW.
14. ATMOSPHERIC CONDITIONS
14.1 The atmosphere is expected to be dusty. The machines offered shall be suitably tropicalised to work under these atmospheric conditions without any adverse effect on their performance.
15. The temperature rise shall not reach such a value that there is a risk of injury to any insulating material or adjacent parts.
16. The drive shall be capable of operating at any one of the speed required independent of the load in accordance with the requirements of the machine.
17. The enclosed Annexure A gives technical data which shall be completed and submitted with the tender, separately for each motor/control gear.
ANNEXURE “A” TO SCHEDULE-II
TECHNICAL PARTICULARS OF A.C. MOTORS AND CONTROLL GEARS
1.1 Manufacturer’s Name
1.2 Type of enclosure
1.3 Type of duty (Ref. IS: 325) (Latest)
1.5 Output (KW/BHP)
1.6 AC voltage across phases, number of phases & frequency.
1.7 Speed in RPM
1.8 Class of insulation
1.9 Normal full load current
1.10 Starting current
1.11 Maximum current at the time of change over from lower speed to higher speed
1.12 Type of motor-Squirrel cage/slipring (wound rotor)
1.13 Temperature rise of windings & other parts allowed above an ambient temperature of 50 degree C.
1.14 Frame size of motor
1.15 End use of motor
2. CONOTROL GEARS
2.1 Manufacturer’s Name
2.2 Type of control gear (Direct on line/Star Delta/Auto-transformer etc.)
2.3 Rating of starting gear in KW & amps.
2.4 Are the following provided:
2.4.1 Short circuit protection
2.4.2 No volt trip
2.4.3 Overload trip
2.4.4 Delayed action current sensitive single phasing preventor
3. Standard specifications to which the motor control gear and its ancillary offered conform to
4. Any other special features.
ANNEXURE “B” TO SCHEDULE-II
1.1 Manufacturer’s Name
1.2 Type of enclosure
1.3 Type of duty (Ref. IS: 4722) (Latest)
1.5 Output (KW/BHP)
1.6 DC voltage across phases, number of phases & frequency
1.7 Method of excitation whether shunt, series, compound or separately excited, if separately excited state excitation voltage.
1.8 Speed in RPM
1.9 Class of insulation
1.10 Normal full load current in amps.
1.11 Starting current
1.12 Temperature rise of windings & other parts allowed above an ambient temperature of 50 degree C.
1.13 Frame size of motor
1.14 End use of motor
2. CONOTROL GEARS
2.1 Manufacturer’s Name
2.2 Type of control gear (Direct on line/Resistance type/Thyristor type)
2.3 Rating of starting gear in KW & amps.
2.4 Are the following provided :
2.4.1 Short circuit protection
2.4.2 No volt trip
2.4.3 Overload trip
3. Standard specifications to which the motor control gear and its ancillary offered conform to
4. Standard specification to which control gear conforms to.
5. Any other special features.
ANNEXURE “C” TO SCHEDULE-II
TECHNICAL PARTICULARS OF VOLTAGE STABILISER, ULTRA ISOLATION TRANSFORMER
1. VOLTAGE STABILISER
1.1 Manufacturer’s Name
1.2 Type of voltage stabiliser :
a) DC servo motor type
b) AC servo motor type
c) Solid state
1.3 Rated capacity in KVA
1.4 Nos. of phases & frequency
1.5 Type of input supply unbalanced
1.6 Input voltage
1.7 Output voltage
1.8 Rate of correction
1.9 Class of insulation & winding (only copper wound is acceptable)
1.10 Type of control circuitry
1.11 Class of duty
1.12 Type of cooling
1.13 Indicating instruments and their ranges
1.14 Safety features
2. ULTRA ISOLATION TRANSFORMER
2.1 Manufacturer’s Name
2.2 Rated capacity
2.3 Ratio of input/output voltage
2.4 Class of insulation
2.5 Arrangement for suppression of power line surges, spikes, transients and noises
2.6 Type for cooling.
1. RIGIDITY AND STABILITY
1.1 The machine shall be robust, rigid and of sturdy construction. It shall be designed to meet heavy duty demands of various operations on the machine under normal Workshop environment for such machines. It shall be free for vibrations even when working at full capacity.
1.2 All machine castings shall be made of close grained high grade cast iron like Meehanite or equivalent materials meeting IS-210 Standards to ensure durability and rigidity. The casting shall be thermal stress relieved to ensure stability and continued accuracy.
1.3 All machine fabrications of critical load bearing assemblies like beds, columns etc. shall be adequately strengthened and stress relieved.
1.4 Change in ambient temperature shall not effect the performance of the machine.
1.5 There shall be no change in the performance of the machine either on switching on the machine or after continuous running.
1.6 There shall be no resonant vibrations throughout the working range of the machine at all load levels.
2. SAFETY CONTROLS
2.1 The machine shall incorporate safety devices to provide protection to the operator and machine against all possible operational and machinery failures.
2.2 Suitable interlock shall be provided to prevent machine operations in the event of:
- Faulty sequence of operation.
- Fluctuation in supply voltage.
- Resumption of power supply after power failure.
- Non-positioning of safety guards.
- Failure of hydraulic system (where applicable)
- Failure of lubricating system (In case of automatic including drop in pressure lubrication)
2.3 A fault or damage in the control circuit or interruption re-establishment after an interruption of fluctuation in whatever manner in the power supply to the machinery must not lead to dangerous situations in particular.
- The machinery must not start unexpectedly.
- The machinery must not be prevented from stopping if command has already been given.
- No moving part of the machinery or piece held by the machinery shall fall or be ejected.
- The protection devices must remain effective.
2.4 The machine shall be fitted with an emergency stop device to enable actual or impending danger to be averted. This device must be
- Conveniently located.
- Clearly identifiable.
- Stop the machine as quickly as possible without causing additional hazards.
The emergency stop must remain engaged. It should be possible to disengage it only by apapropriate operation. Disengaging the control must not restart the machinery but only permit restarting.
2.5 Safety features shall also include.
- Safety device against overload for all mechanical and electric items to the extent possible.
- Safety stops against over-running of slides.
2.6 Guard and protection devices shall protect exposed persons against risks related to moving transmission parts (such as pulleys, belts, gears, rack and pinion, shafts etc.) and moving parts directly involved in the process to the extent possible. This shall meet the following requirements: -
- Be of robust construction
- Not give rise to any additional risk
- Not be easy to by pass or render non-operational
- Be located at an adequate distance from danger zone
- Cause minimum obstruction to the view of the production process.
- Rigidly connected and not prone to rattling.
- Enable essential work to be carried out without the guard or protection device having to be dismantled.
2.7 A load meter shall be provided to indicate the load on the machine. The meter shall have a suitable mark to indicate the maximum load the machine can take. Full details of the above and other safety features indicating howeach one functions must be explained in the offer.
3. OPERATIONAL CONTROLS
3.1 The operation of the machine shall be by push buttons or levers. The basic rules for the direction of operation of controls and the corresponding direction of movements of the machine tools shall be as per IS:2987-1985.
3.2 The control devices shall be
- Clearly visible and identifiable.
- Ergonomically positioned for safe operation without hesitating or loss of time, and without ambiguity.
3.3 CNC Controls (where applicable) - The general requirements of CNC controls are given at Schedule-IV.
4.1 Integral lighting suitable for the operations concerned where its lack is liekly to cause a risk despite ambient lighting of normal intensity shall be provided.
4.2 The manufacturer must ensure that there is no area of shadow likely to cause nuisance, that there is no irritating dazzle and that there are no dangerous stroboscopic effects due to lighting provided by the manufacturer.
4.3 Integral parts requiring frequent inspection and adjustment and maintenance areas must be provided with appropriate lighting.
4.4 The machine lighting should be of low voltage so as to prevent any hazard to the operator.
5. MACHINE MAINTAINABILITY
5.1 The machine shall be so designed as to require minimum possible maintenance and to give trouble free service.
5.2 All assemblies/parts of the machine shall be easily accessible for maintenance.
5.3 The machine shall not require major dis-assembly for checking and replacement of a particular part, especially for parts requiring periodical check up and replacement.
5.4 The manufacturer must provide means of access e.g stairs, ladders, cat walks etc. to allow access safety to all areas used for production, adjustments and maintenance operations.
6. WEAR COMPENSATION ADJUSTMENT
6.1 The original built in accuracy of the machine shall be capable of being maintained conveniently and economically by suitable adjustments for taking up wear on slides, bearings and load screws. The system of adjustments incorporated shall be explained in the offer.
7. COOLANT SYSTEM (WHERE APPLICABLE)
7.1 Suitable coolant system with pump, motor, tank, filter etc. shall be provided. The coolant pump shall be as per IS:2161-1962. The filter shall be of reusable type and indigenously available. If reusable filter cannot be offered the filter cartridge shall be readily available in India. Source of supply shall be indicated. Adequate no. of filters for 2 years working on double shift basis shall be offered as spare. Details of the coolant system shall be indicated in the offer.
7.2 The supply of coolant shall be in ample volume. Provision to re-circulate the coolant shall be available. A chip and coolant tray shall be provided. The volume of coolant flow shall be indicated. It shall be adjustable.
7.3 An enclosure shall be provided to prevent the coolant from splashing outside the machining zone. Details of enclosure shall be provided. Specific requirements of coolant system for grinding machines etc. shall be clearly indicated.
8. LUBRICATION SYSTEM (WHERE APPALICABLE)
8.1 The machine shall be provided with an automatic lubricating system for ensuring delivery of adequate quantity of lubricant to areas requiring continuous lubrication. Suitable arrangements must be provided for indication of failure of the lubricating system.
8.2 The system shall be provided with interlock to prevent machine operating/starting in the event of the failure lubrication system.
8.3 Reusable filters capable of filtering chips, dust particles etc. shall be provided. Indicators for showing clogged condition of filters shall be available. The filters shall be indigenously available. If reusable filter cannot be offered the filter cartridge shall be readily available in India. Source of supply shall be indicated. Adequate no. of filters for 2 years working on double shift basis shall be offered as spare.
8.4 Lubrication and filter cleaning chart shall be displayed on a metal plate at a conspicuous location on the machine indicating: -
(a) Specific location of points on the machine to be oiled lubricated/greased.
(b) Periodicity of lubrication of these points.
(c) Filter to be cleaned.
(d) Periodicity of cleaning filters.
(e) Periodicity of replenishing lubricating oil for the centralized system.
(f) Any other similar relevant information.
8.5 Points where manual lubrication is needed shall be separately indicated. Frequency of lubrication shall be also clearly mentioned.
8.6 Lubricating oils used in the machine shall be available in India. Successful tenderer will be required to indicate brand names of approved oils manufactured by various Indian Oil Companies.
8.7 First fill of lubricating oils used in the machine shall be provided with the machine. Details of lubricating system provided shall be indicated.
9. PNEUMATIC SYSTEM (WHERE APPLICABLE)
9.1 The compressed air supply will be provided by the customer at the machine within pressure range of 4.5-7.5 kg.cm2 and a moisture content or 1000 ppm. The pneumatic system of the machine should be designed accordingly. An alarm shall be provided for low air pressure.
9.2 Suitable filter/moisture trap shall be provided by the contractor in the system of pneumatic air intake. The filter shall be reusable type and indigenously available. If reusable filter cannot be offered, the filter cartridge shall be easily available in India. Source of supply shall be indicated. Adequate no. of filters for 2 years working on double shift basis shall be offered as spare.
9.3 Air pressure regulator, if necessary, shall be provided by the tenderer.
9.4 The make of pneumatic control equipment shall be of reputed make. The makes shall be indicated.
10. HYDRAULIC SYSTEM (WHERE APPLICABLE)
10.1 Hydraulic circuit must be equipped with the following safety and inspection equipments:
(a) Pressure gauges at all places, where pressure has to be set up or inspected.
(b) Safety valves for hydraulic circuit if relief valve does not fulfil this function.
(c) Equipment for checking of temperature in the circuit or in the pump wherever necessary.
(d) Arrangement to show if the filters (including those in the pump set) are choked and need cleaning. The filters shall be of reusable type and indigenously available. If reusable filter cannot be offered, the filter cartridge shall be readily available in India. Source of supply shall be indicated. Adequate no. of filters for 2 years working on double shift basis shall be offered as spare.
(e) Alarm for low oil level.
10.2 The sump aggregate shall have the following:
(a) Oil level sight gauges or any other equipment showing the minimum and maximum oil levels in sump.
(b) A drain plug at the lowest portion of the tank.
(c) It shall be possible to drain the oil from the tank without disconnecting any pipes or other fittings.
10.3 The temperature of oil in hydraulic circuits shall not exceed 60 degrees C in any case. Suitable arrangement shall be incorporated to ensure that the oil is not overheated under local weather conditions at continuous normal working of the machine.
10.4 Facilities for bleeding of air in case of air lock shall be provided.
10.5 The hydraulic reservoir, pump and allied equipment shall be suitably segregated from the machine in order to remove major source of heat.
10.6 Hydraulic oils used on the machine shall be available in India. Successful tenderer will be required to indicate brand names of approved oils supplied by various Indian Oil Companies.
10.7 First fill of hydraulic oils used on the machine shall be provided with the machine.
10.8 The hydraulic system elements shall be from reputed Indian manufacturers like M/s. REXROTH, Vickers-Sperry, Yuken, L&T etc. The make of different elements shall be clearly indicated. Details of Hydraulic system shall be indicated.
The following information should also be furnished in the offer for the machine.
Compressed air requirements with air pressures and consumption etc.
Pressure, consumption requirement and quality of water.
Approx. working area requirement including material stacking for efficient working.
Change over cycle time for loading and unloading.
Connected load of machine in Kilo Watts.
Type and make of CNC system should be clearly specified.
The make of all AC drives.
The air conditioning arrangement for cooling of CNC panel, electrical panel, high voltage portion & laser portion.
Programming station recommended for the machine.
Various inputs/outputs status should be available on screen.
PLC of one of the following makes only shall be provided". Siemens, Allen Bradley and Fanuc. It shall be of latest version. Ladder diagram for the PLC shall be supplied along with the machine.
Annexure - D
1. Sequence of Assembly of Sidewall and roof:
The bidder shall design the fixture as per the details given below:
In this stage the details like Body pillar, Waist rail, Light rail, etc are tack welded with sidewall sheet using suitable locators with adequate clamping. The fixture shall be capable of assembling Body sidewalls as per the drawing numbers shown in Annexure – I to schedule-I including Lavatory sidewalls. The fixture shall be capable of assembling both LH & RH sidewalls without any modification.
The tack-welded sidewall is spot
welded in this stage
2. The sequence of assembly of details in the Tack welding fixture as given below: -
Position sidewall sheet/sheets and hold by using Pneumatic clamps preferably. Arrangement should be given to stretch the sidewall sheets by suitable pulling mechanism to remove sagging / waviness. The pulling should be uniform from both the ends. It is required to have necessary pulling locations on each end to optimize the pulling force distribution to reduce undulations to the minimum level.
Position the profiled stiffeners like light rail, waist rail running along the length of the sidewall with suitable locators and clamp with sidewall sheet and tack weld.
Position body pillars by using locators and clamp with sidewall sheet. The clamping shall be done by using pneumatic down holders capable of traversing along the full length of the fixture. The positioned body pillars are then tack welded.
3. The sequence of assembly of details in Spot welding fixture is as given below: -
3.1 The fixture in this stage shall be capable of holding the tack-welded sidewall suitably to carryout spot welding operations as per drawing.
4. Design: -
The following aspects should be incorporated while designing the fixture.
The main structure of the fixture must be rigid and grouted on the floor.
The fixture should be convenient to work and floor space saving. Accordingly, the design in which the sidewall can be assembled in the vertical position is preferable. The tack welding fixture bed should locate and clamp the sidewall sheet by using Pneumatic clamps.
All the clamps should be Pneumatically operated.
All the clamps and locators should be made flexible, so that the locators and clamps can be repositioned easily for different types of coaches without affecting the dimensional accuracy.
The locating and holding /clamping mechanism using traverser type of arrangement shall hold pillar and other stiffeners along the length of the sidewall. Sufficient numbers of traversers carrying flexible clamps or any other appropriate arrangement to clamp body pillars and other stiffeners have to be provided. These traversers should be capable of moving along the full length of the fixture. Adequate number of spare traversers to be supplied along with the fixture.
Assembled sidewall to retain dimensions after clamps are released.
The fixture should be capable of assembling LH & RH sidewalls.
The fixture should be modularized capable of assembling full length of sidewall and also there should be provision for assembling sidewall in segments.
The fixture should accommodate both curved sidewall and straight sidewall with slight addition / removal/adjustment of modules.
Easy accessibility should be ensured for Manual Metal Arc Welding /Co2 Welding / Spot Welding of Detail components in the Fixture.
The design of the tack-welding fixture should be based on sound ergonomic aspects both for assembly as well as welding.
The entire fixture should be in modules of convenient length for easy handling.
The CNC System offered shall have following features:
The CNC control shall be with high processing speeds. It shall be based on the latest multi-processing/multi- tasking technology for welding operations.
The CNC control shall ensure easy man-machine interface/ communication.
Manual override feature.
Storage capability for Programme with quick access to main and sub-programmes.
Fixed cycle and sub-Programme facility.
Manual data input with edit facility.
Interactive graphics with Programme simulation and dry run capability.
DNC capability/linkup with RS 232 port for controlling production.
Facilities for simultaneous programming.
CAD/CAM capability including graphic simulation on CRT system /Colour Graphic control (12"CRT Screen).
Battery Backup for retaining memory during power shut- off/failure.
Complete self-diagnostic capability for ease in maintenance.
The off-line programming equipment with interface.
A voltage stabilizer with spike and surge filter and an ultra isolation transformer shall be provided for protection of CNC system.
Travel measurement with incremental positional encoder.
The machine should have microprocessor based performable weld controller for control of welding current, electrode force and welding cycle. Four basic steps like squeeze time, weld time, hold time and off time must be programmable.
The Synchronous welding control should be available with the machine. Maximum number of programmes should be supplied with the machine for various material compositions and thickness in which if the operator selects the thickness and material combination, welding parameters should be automatically selected. Further programming for positioning of machine at different locations to make welds should be separate.
In the event of electronic malfunctioning occurring, the robot welding system shall go to stop mode.
Adaptive control feed back system, which should ensure consistency in Spot weld with variation in line voltage, electrode deterioration, change in surface resistance (due to variation in thickness of sheet etc.) and force system.