Reasoned documents of Comments received from the Firms ITEM: BRUSHLESS DC RAILWAY CARRIAGE FAN

RDSO draft Specification No. RDSO/PE/SPEC/TL/0021/2005 (REV ‘3’)

Clause No.

Description as per Draft Specification no. RDSO/PE/SPEC/TL/0021/2005 (REV ‘3’)

uploaded on website

Comments received RDSO’s comments

2.1 This specification covers the requirements of design, manufacture, testing and supply of 400mm sweep BLDC railway carriage fans for rolling stock application complete in all respect suitable for input voltage of 110V ac/dc system.

M/s R.Kanwar The Input Voltage has been mentioned as 110V ac/dc, we expect that since these are BLDC Fans and whole of the specification including performance & testing etc. are based specifically for DC Supply only, as such it may be 110 VDC Only. M/s GAEC The fan presently is designed for 110V DC operation. For making this suitable for AC and DC both, some components and values need to be changed/added for its reliable operation. This may add some complexity in operation and also the cost. In our opinion, this may be restricted to 110V DC only.

RDSO’s comments: For making fan suitable for AC / DC operation both, some components and values need to be changed / added for its reliable operation. This may add some complexity in operation and also the cost may be high, hence accepted. Modified clause

This specification covers the requirements of design, manufacture, testing and supply of 400mm sweep BLDC railway carriage fans for rolling stock application complete in all respect suitable for input voltage of 110V DC system.

2.3 Input to the unit will be fed through battery bank of 110V dc in parallel with alternator, rectifier cum regulator. The unit shall be suitable for operating voltage available as input i.e. 90V to 140V DC with 15% ripple. There may be surges in input supply with peak value of approximately 350V. However it is advised that the firm may measure the harmonic distortion and Surges in the Coach before designing the BLDC fan. The over voltage trip shall be set at 155V with suitable time delay.

M/s R.Kanwar Sir as agreed & pointed out by your honour in this clause that the harmonic distortion and the surges in the input supply is due to the alternator & rectifier cum regulator, as such Imposition of the same only on BLDC fan manufactures does not seems to be justified and is partiality. We understand that it will be justified if for the safe guard / beneficiality for all the electrical equipments & accessories the same instructions / amendments / orders are issued to the O.E.M of the alternator & rectifier manufactures.

RDSO’s comments: Setting of over voltage tripping exactly at 155V may not be possible because of variation at input supply, therefore over voltage trip between 150V- 155V deleting “with suitable time delay” may be considered Modified clause

Input to the unit will be fed through battery bank of 110V dc in parallel with alternator, rectifier cum regulator. The unit shall be suitable for operating voltage available as input i.e. 90V to 140V DC with 15% ripple. There may be surges in input supply with peak value of approximately 350V. However

In support of the same we here by once again enclose the 4 letters (joint reports) received from the railways indicating that all the fans were found burned due to this reason only. The over voltage trip may Kindly be amended from 150V to 155 Volts as earlier. M/s GAEC It may not be possible to arrive at any conclusion for actual harmonics and surges as it will depend on many factors taken together including speed of the train, alternator condition, RRU / ERRU performance, other local factors. However, standard protection is provided to meet Surge Test as per clause 8.16 of the specification. Suitable MOV of 275V is already provided in present design. M/s LEC For protection we have used MOV 325V. I/P cap is divided into 2 i.e. 250V. Implemented EMI/EMC filter set at +155V DC/AC M/s Lucas TVS Needs RDSO support / permission to conduct these tests.

it is advised that the firm may measure the harmonic distortion and Surges in the Coach before designing the BLDC fan. The over voltage trip shall be set between 150V-155V DC.

4.1 The motor of the fan shall be permanent magnet type, light in weight and small in size without field winding, brushes and commutator. The permanent magnet shall be fitted on the rotor in such a manner that it should not get disengaged. It is desirable that the magnet shall be embedded in slots.

M/s R.Kanwar It is surprising and contradictory that in the last of this clause your honour at own has itself permitted and asked for the DEVIATION / MODIFICATION by extending the fan body color in your own RDSO‟s standardized drawing No RDSO/PE/SK/TL/0025-2002 (Rev-

RDSO’s comments: Not accepted, in view if interchangeability of motors of each other make. However Fan body is replaced by fan motor body in the last. Modified clause

The motor of the fan..............Hole diameter:9mm.

Deep drawn design for fan body made from MS sheet shall conform to RDSO drg. No. RDSO/PE/SK/TL/0025-2002 (Rev.0). Motor body shall be of aluminum alloy LM-6. Details of mounting of fan to coach ceiling are as under. PCD : 108 mm; No. of holes: 3 at equal distance; Hole diameter: 9 mm For fixing of fan guard, extension of fan body collor or provision of additional collor shall be used.

0) for deep drawn fan body for fixing of the Fan Guard. Where as for this purpose the separate additional color can be attached, however the better way is to provide the same by extending the fan motor body with “M8-20mm” long screw as permitted & adopted earlier for better look &safty purpose etc. M/s Lucas TVS Magnet shapes & size is defined in RDSO drawing No. RDSO/PE/SK/TL/0153-2011 (Rev.1) – Sheet 2. Hence, embedded slot design cannot be used. LTVS need the drawing hardcopy in original paper size. (Deep drawing design RDSO drg. No. RDSO/PE/SK/TL/0025-2002 (Rev.0)

For fixing of fan guard, extension of fan body collor or provision of additional collor shall be used.

4.2 PROPERTIES FOR PERMANENT MAGNET:- The permanent magnet to be used on the fan shall have the following properties:

Value of coercive force shall be advised after designing the fan.

Hardness of the magnet shall not exceed 700 HV.

It shall have smooth ground surface.

It shall meet the requirement of clause 8.6 of this specification.

Rotor magnet shall have 1350-1750 Gauss.

M/s R.Kanwar Sr. No. „4‟, it may kindly be Corrected as Clause No. ‘8.7’ instead of ‘8.6’. Sr. No. „5‟, The Gauss Value may kindly be amended as 1300 – 2000 for better performance (as earlier). M/s LEC Agreed. However regarding the thickness tolerance we would request not to reduce tolerance & ±0.5mm tolerance be permitted. M/s Lucas TVS It has to be changed to Clause 8.7 as Clause 8.6 deals with voltage protection.

RDSO’s comments:

Clause No. Corrected

Range of Gauss values is reduced to obtain better performance, hence not changed.

Modified clause

Clause No. Corrected

No change

4.3 BLADES:- Fan blades shall conform to RDSO drg. No. RDSO/PE/SK/TL/0108-2008 (ALT „2‟) (Rev.0) and shall be easily replaceable / interchangeable.

M/s Lucas TVS LTVS need the drawing hardcopy in original paper size.

RDSO’s comments:

ALT „2‟ is replaced by ALT‟1‟ or latest Added” M/s. Paras Plastic, Mumbai /

M/s. Qumex Mould, Kolkata make blades shall be used. Any other source of blade with prior approval of RDSO shall be used.”

Modified clause

Fan blades shall conform to RDSO drg. No.RDSO/PE/SK/TL/0108-2008 (ALT.1) (Rev.0) or latest and shall be easily replaceable / interchangeable. M/s. Paras Plastic, Mumbai / M/s. Qumex Mould, Kolkata make blades shall be used. Any other source of blade with prior approval of RDSO shall be used.

4.4.1 PCB output supply (3phase) to the fan motor will be such that the pulsating torque is within permissible design limit.

M/s LEC Explanation required. M/s GAEC This phenomena should be explained in detail and reviewed

RDSO’s comments: verification of the pulsating torque within permissible design limit is not possible, hence this clause is deleted. Modified clause

Clause deleted

4.4.2 All new manufacturers will develop fan only with Digital Signal Processer (DSP) based controller, to reduce number of components. Existing approved sources with Sensor less design who got approval prior to revision of this specification without DSP based controller, shall also develop DSP based PCB in due course.

M/s R.Kanwar The requirement / development of DSP controller may kindly be deleted for the existing manufacturers & left to the new developers only. M/s GAEC Use of DSP controller may not be enforced for existing manufacturers, as this will not lead to any advantage and will increase the cost. Also for existing approved manufacturers, proving new design in the field may lead to additional issues. Also in our opinion, DSP control is required where precise control of speed is required in variable speed drive. Here, in present design, our requirement is for ONE constant speed. Hence, using DSP control may not contribute any additional feature. M/s Lucas TVS Please inform the components, those get reduced because of DSP.

RDSO’s comments: DSP control is required where precise control of speed is required in variable speed drive; in present design speed of fan is constant for the input voltage range of 110V DC to 140V DC. Introducing new design in the field may lead to additional issues. Also. However, use of DSP based controller is added as optional. Modified clause

The manufacturer shall develop Brushless DC fan using Digital Signal Processer (DSP) or microcontroller based PCB.

4.4.3 The Controller Card shall be used with three phase output voltage of 54V with provision of 6 nos. mounting holes as per RDSO drawing No. RDSO/PE/SK/TL/0153-2011 (Rev.0)-Sheet 1 of 4 (or latest).

M/s R.Kanwar The tolerance in three phase output voltage of the controller card may please be modified to 54V + 2V due to the fact that there is plus minus tolerance in electronic components and No of turns in the stator winding. M/s GAEC Presently, the cards are designed based on same. However, some variation in output voltage is observed with respect to input voltage. However, speed remains fairly constant with respect to input voltage variation.

RDSO’s comments: As this 54 volt is no where concern with the design of controller card and the wattage of the fan is mentioned as less than 32W, hence deleted from the clause. Modified clause

The Controller Card shall be used with three phase output voltage with provision of 6 nos. mounting holes as per RDSO drawing No. RDSO/PE/SK/TL/0153-2011 (Rev.0) - Sheet 1 of 4 (or latest).

4.4.4 PCB will be fixed on the motor body only on three inner holes. This requirement is essential to standardize the fixing arrangement. In future, the number of holes in PCB can be reduced from six to three. It will make more space available on PCB with three holes.

M/s R.Kanwar Our opinion / request is that for more mechanical and electrical strength etc. the PCB shall be fixed also on the outer three holes however the inner 3 holes are only for the interchangeability purpose, which has already been standardized by RDSO, this will help the interchangeability in old BLDC Fans also.

RDSO’s comments: In view of interchangeability with the existing/old fans in the field, Provision of six holes will be required, Modified clause

PCB shall be fixed on the motor body only either on three inner holes or on three outer holes.

4.4.5 Assembled PCB shall be given a conformal coating to enable them for functioning under adverse environmental conditions. Soft or hard potting under any circumstances may not be acceptable. PCB will be suitable for satisfactory performance without any soft/hard potting.

M/s LEC We are already using conformal coating on our PCBs.

RDSO’s comments: --- Modified clause

No change

4.4.9 The Connector for 3 phase shall be provided as per RDSO drawing No. RDSO/PE/SK/TL/0153-2011 (Rev.1) – Sheet 1 (latest). It shall be compulsory in order to ensure correct configuration of R, Y, B at the output. It will ensure interchangeability of PCB.

M/s Lucas TVS LTVS needs the drawing hardcopy in original paper size.

RDSO’s comments: Drawings copy is attached with the specification. Modified clause

No change except Rev. „0‟ in place of Rev‟1‟

4.5.1 ROTOR: 4 pole rotor magnet and shaft used in BLDC fan shall be as per the RDSO drawing No. RDSO/PE/SK/TL/0153-2011 (Rev „1‟) – sheet 2 and 3 (latest) respectively.

M/LEC The sensor magnet has been eliminated from the BLDC motor as per the Rev. 3. So we suggest that the length of shaft should be reduced. M/s GAEC Since the possibility of use of sensor magnet has been totally eliminated in Rev „3‟ being sensor less type, we suggest that length of rotor shaft be reduced suitably.

RDSO’s comments: Accepted, length of shaft is reduced by 34 mm, drawing is corrected accordingly. Modified clause Drawing No. Corrected.

4.6 STATOR M/s R.Kanwar The stack length of the stator may kindly be modified to 11.5 + 0.5 mm due to the reason that the thickness of the laminated sheet is also 0.5 mm. M/s LEC Stack length:11.5±0.50mm be permitted.

RDSO’s comments:

Accepted, The stack length of the stator may be modified to 11.5 + 0.5 mm Modified clause

The stack length of the stator is modified to 11.5 + 0.5 mm

4.7 Printed as 4.5.1 M/s R.Kanwar The 4.5.1 Should be Rotor

RDSO‟s Drg. No RDSO/PE/SK/TL/0153-2011 (Rev-1) sheet 2 of 4.(Rotor Magnet)

i) The thickness of the rotor may please also be modified to 11.5 + 0.5 mm due to the reason that the thickness of the laminated sheet is also 0.5 mm. ii) The Gauss value of the permanent magnet may please also be modified as 1300-2000 for better performance please. RDSO‟s Drg. No RDSO/PE/SK/TL/0153-2011

(Rev-1) sheet 3 of 4.(Shaft) Sir, Further from the above drawing we

RDSO’s comments: Revision of drawing is modified and clause No. Is corrected as 4.7 Modified clause Revision of drawing is modified and clause No. is corrected as 4.

observe that towards the blade side of the shaft M4 left handed threading is not required when the counter pin & screw are provided after providing the blade (left hand side of the drawing) Secondly since now the sensor magnet is not required / provided as such the provision of 9 mm long grove / flatness is also not required (Right hand side of the drawing). In addition to above due to the fact that all the mechanical work on the shaft is done only centre to centre by the very precious & S.P.M (Special Purpose Machine) etc. as such the balancing of the shaft is not at all required. In view of the above it is requested that the above drawing may please be modified accordingly.

4.11 GUARD: Crashworthy design of fan guard shall conform to ICF drg No. ICF/SK-7-6-158 alt. „E‟.

M/s LEC The ICF drawing No. ICF/SK-7-6-158 Alt. „G‟ of modified version of guard has been issued by RDSO. M/s GAEC The drawing for Fan Guard is recently reviewed and modified to ALT „G‟. Please confirm the same.

RDSO’s comments: Accepted, „or latest‟ added Modified clause

GUARD: Crashworthy design of fan guard shall conform to ICF drg No. ICF/SK-7-6-158 alt. „E‟ or latest.

6.2 An oval shape rectangular plate of size 50 mm x 30 mm fixed by two screws or rivets shall be provided on the fan motor for marking of Railway Code initials and serial Number separately.

M/s R.Kanwar The Fan body may please be mentioned against the fan motors for Providing Rectangular plate & Railway code etc.

RDSO’s comments: Accepted Modified clause

An oval shape rectangular plate of size 50 mm x 30 mm fixed by two screws or rivets shall be provided on the fan body for marking of Railway Code initials and serial Number separately.

7.1 Type tests shall be carried out by RDSO on five samples of BLDC fans of the same type selected from the lot available at the premises of the manufacturers. One fan shall used for endurance tests after carrying out all tests except tests mentioned at clause 8.9. However, temperature of Insulated windings, accessible external surface metallic / non-metallic, surface and bearings shall be recorded at the end of the endurance test and shall not exceed the limits given in Table at clause 8.10.

In respect of tests for which testing facility is not available with the manufacturer, the same may be carried out at NABL accredited test house / lab and test reports shall be submitted to RDSO.

M/s R.Kanwar The measurement of the temperature of non metallic surface is not required as per table given at clause no 8.10 the same may please be deleted.

RDSO’s comments:

Accepted as there is no any non metallic surface Modified clause

non-metallic deleted from the clause.

7.2 The following type, routine and acceptance tests shall be conducted on Brushless DC Railway Carriage Fans

M/s R.Kanwar The request / comments and observations for Type, Routine & Acceptance Tests may kindly be reviewed for practicable aspects as under please :- Sr. No. (1) to (20) – all are acceptable except Sr. No. (14) Air Delivery Test, which has been added in Routine & Acceptance Tests both, i.e on each and every fan, as such your honour is requested to kindly keep the same as earlier i.e as per Rev-„2‟ for practicable point of view. M/s GAEC In this, Air Delivery Test (Including Service Factor) has been added in Routine test on 100% lot. This is not feasible to carry out this test on all the units. It is requested to restore

RDSO’s comments: Air delivery test on every 500

th unit is

considered in line with Rev‟2‟ specification. Modified clause

Corrected in the specification.

as per OLD to every 500th Fan. Also for Noise Test and Air Delivery Test during Acceptance Test, there was additional sampling of Max 6 fans for lot size above 200 nos has been removed. For carrying out Noise and Air Delivery Test on all the samples during acceptance test is again Not Feasible. It is requested to restore as per original clause. M/s Lucas TVS SN 19 – Test procedure is not clear in Clause 8.18. Detailed specification required. SN 20 – There is no such clause reference available in the specification. Hence needs clarification.

8.1 VISUAL INSPECTION: All components shall be visually examined for finish. Surface Finish of shaft, magnet and blade to be measured, compared with their drawing and recorded. Guard, blade and fan motor body shall be verified for their dimensions and material specification. The manufacturer shall furnish test report of blade, permanent magnet material, Alluminium motor body, stator copper conductor, stator core as specified in Clause 4.3 and 4.2 respectively.

M/s R.Kanwar It is requested to kindly add the following in the last line of this para that the material specification and the test report for the aluminium motor body, stator copper conductor. Stator core and guard may please be verified from the purchase bills (Suppliers Bills) M/s GAEC For verifying Surface finish of shaft and magnet, the fan motor needs to be opened. This may be accepted against Fan Manufacturers Certificate during Acceptance Tests.

RDSO’s comments:

Verifying Surface finish of shaft and magnet is difficult as the fan motor needs to be opened every time. However, the test report for the aluminium motor body, stator copper conductor. Stator core and guard may be verified from the purchase bills (Suppliers Bills) Modified clause

All components shall be visually examined for finish. Guard, blade and fan motor body shall be verified for their dimensions and material specification. The manufacturer shall furnish test report of blade, permanent magnet material, Aluminium motor body, stator copper conductor, stator core as specified in Clause 4.3 and 4.2 respectively.

8.3 STARTING TEST: The fan shall be capable of starting from rest at ≤75 volts.

M/s R.Kanwar Keeping in view the tolerances the ≤ 75 V may please be modified from 72V to 75V.

RDSO’s comments: The fan shall be

started at ≤ 75 V. Modified clause

No change

8.5 ELECTRICAL INPUT TEST: The electrical input in watts to the fan shall be determined by the running the fan at rated voltage. However input watts at other voltages i.e. 90, 100, 120, 130 and 140 V shall also be recorded for reference purpose.

M/s R.Kanwar The input watts at other than rated voltage may kindly be modified to be recorded for reference purposes during prototype testing only.

RDSO’s comments:

input watts at other voltages i.e. 90, 100, 120, 130 and 140 V is required to be recorded during prototype test only Modified clause „during prototype test‟ added in the clause.

8.6.1 Input over voltage protection shall be provided in the circuit so that whenever input voltage increased beyond 155V, the fan shall trip and whenever the voltage comes down to 140V, the fan shall start automatically. A time delay shall be provided to avoid tripping of the fan or hunting due to instantaneous over voltage / under voltage. Input over voltage supply with time duration less than the delay incorporated in the design shall be applied and tested to ensure that fan does not trip.

M/s R.Kanwar The input over voltage protection has been mentioned as 155V the same may please be modified as 150V to 155V accordingly the fan tripping voltage may please also be modified as 142V to 145V. M/s LEC Solution goes to standby mode above 155V and restart ≤140V automatically. System check 50 times and do averaging before taking action and to avoid frequent tripping in case of fluctuation/serge. Time delay of 25~30mSec is provided. There is sufficient time before taking action for high/low voltage protection triggering. Also, if voltage remains high & low for longer time in that case we do have on-the-fly feature to support continuous motor of fan in run-time. M/s GAEC Increasing over voltage trip limit to 155V is acceptable. However, limit may also be specified as restart voltage between 140 – 145V as it is not feasible to restart the fan exactly at 140V.

RDSO’s comments: Accepted as hysteresis of 5V is considered for trip and start automatically. Time delay feature is not required in this case. Modified clause

Input over voltage protection shall be provided in the circuit so that whenever input voltage increased between 150V to 155V, the fan shall trip and whenever the voltage comes down between 140V to 145V, the fan shall start automatically

Also to measure time delay, it should be measured after applying voltage beyond trip voltage and find out the delay time for fan to trip. It will be extremely difficult to apply over voltage with less than delay time.

8.6.2 Input under voltage protection shall be provided in the circuit so that whenever input voltage decreased below 65V, the fan shall trip and whenever the voltage comes above 70V ( 5V Hysteresis), the fan shall start automatically. A time delay shall be provided to avoid tripping of the fan or hunting due to instantaneous over voltage / under voltage. Input under voltage supply with time duration less than the delay incorporated in the design shall be applied and tested to ensure that fan does not trip. Capability to withstand input of 200V DC without any damage to any part of the BLDC fan for two minute shall also be provided. This shall be tested for 30 minutes during type test and for 2 minutes during routine and acceptance test.

M/s R.Kanwar The input under voltage protection tripping voltage may kindly be modify as 62V to 65V and the restarting voltage may kindly also be modify as 72V to 75V (10 V Hysteresis) Note:-The Comments / observation against 8.6.1 & 8.6.2 are based on the tolerance of the + variation in the electronic components and stator winding. Which has already been accepted by RDSO Vide L.NoEL/6.5.1/BLDC/ RKE Dated 26-05-2014 (Copy Attached) M/s LEC Solution goes to standby mode below 65V and restart <70V automatically. System check 50 times and do averaging before taking action and to avoid frequent tripping in case of fluctuation/serge. Time delay of 25~30mSec is provided. There is sufficient time before taking action for high/low voltage protection triggering. Also, if voltage remains high & low for longer time in that case we do have on-the-fly feature to support continuous motor of fan in run-time. M/s GAEC If fan is to start at voltage below 75V, this limit of hysteresis should also be kept same. It is difficult to discriminate between rising voltage from ZERO during start or voltage dip to less

RDSO’s comments:

The fan shall start ≤75V, therefore 5V Hysteresis is deleted. In view of this, time delay feature is also not required in this case. Modified clause

Input under voltage protection shall be provided in the circuit so that whenever input voltage decreased below 65V, the fan shall trip and whenever the voltage comes above ≤75V the fan shall start automatically. Capability to withstand input of 200V DC without any damage to any part of the BLDC fan for two minute shall also be provided. This shall be tested for 30 minutes during type test and for 2 minutes during routine and acceptance test.

than 60V and then restart at less than 70V. Else, Fan start voltage may be kept at 69 to 70V. This is mainly to reduce complex design feature. As stated above, the time delay should be measured by applying voltage at which trip initiates.

8.7 HEATING TEST ON PERMANENT MAGNET: Before starting of the test, magnetism of the magnet shall be measured with the help of flux meter. The shell of the fan motor with magnet fixed shall then be heated up at 1200C for 3 hrs. Continuously. After that, it shall be removed from the oven and cooled to the room temperature. The flux of the magnet shall be measured again.The difference in these two-recorded values i.e. before and after heating shall not vary by more than 5%.

M/s R.Kanwar The manufacture may kindly be allowed to measure the magnetism of the magnet either by flux / gauss meters (any one) Please add the same.

RDSO’s comments:

flux mater and gauss meters are the same , hence no change Modified clause

No change

8.16 ENVIRONMENTAL TEST ON COMPLETE ELECTRONIC DEVICES: These tests shall be conducted on the complete electronic devices such as card, electronic controllers used for commutation in the Carriage Fans as per the standard specified against each test.

i) Voltage surge test - Clause5.4 of

IEC 571-1 ii) Dry Heat test * - Clause 10.2.4 of

IEC 60571 iii) Damp Heat test - Clause 10.2.5 of

IEC 60571 iv) Burn-in test - Clause no.

7.7 of RDSO Spec No.ELRS/

M/s Lucas TVS There is no such clause reference related to this test is available in the specification. Hence needs clarification.

RDSO’s comments: IEC 571-1 is corrected as 60571 Modified clause

These tests shall be conducted on the complete electronic devices such as card, electronic controllers used for commutation in the Carriage Fans as per the standard specified against each test.

i) Voltage surge test - Clause5.4 of IEC 60571 ii) Dry Heat test * - Clause 10.2.4 of IEC 60571 iii) Damp Heat test - Clause 10.2.5 of IEC 60571

SPEC/SI/0015-Oct-2001

* However, dry heat test shall be

conducted at 80C.

iv) Burn-in test - Clause no. 7.7 of RDSO Spec No.ELRS/ SPEC/SI/0015-Oct-2001

* However, dry heat test shall be

conducted at 80C.

8.18 Shock Pulse Measurement: Shock Pulse measurement shall be conducted during proto type tests and values shall be recorded for future reference. These values shall be ensured during Acceptance and Routine tests.

M/s LEC Details of measurement and method must be provided. We suggest that this test should be included only in type tests. M/s GAEC Details of measurement and method should be provided in detail. As special test facility will be required, we suggest that it be included in type test only and test performed at NABL accredited laboratories

RDSO’s comments: Shock Pulse measurement for fan is not required, hence deleted Modified clause

Deleted

9.0 SAMPLING PLAN FOR ACCEPTANCE TEST: Method for sampling of fans for conducting acceptance tests shall be as per Annexure D Table 3 (Clause 19.1.2.1) of IS: 6680.

M/s LEC The sampling plan as per RDSO‟s specification RDSO/PE/SPEC/TL/0021/2005 (Rev. 2) shall be retained. M/s R. Kanwar Sampling plan for Acceptance Test:- For Practicable point of view the same may please be kept the same as earlier (i.e. in Rev-2.) M/s GAEC Sampling size for Noise Test, Air Delivery Test and Service Value must be reduced than regular sampling size.

RDSO’s comments:

Accepted, as the same issue was discussed and finalised for Rev.‟2‟ specification Modified clause

Clause corrected as per Rev „2‟ of specification

12.0 TECHNICAL INFORMATION: The manufacturers shall supply the following technical information in respect of Brushless dc fan.

M/s R. Kanwar This may kindly be applicable during prototype testing only. The same kindly be added.

RDSO’s comments: Accepted ‟ during prototype test‟ added. Modified clause

Clause corrected by adding ‟ during

prototype test‟ and „from the OEM‟ in XII-XIV

15.0 Interchangeability of fan components:- Fan blade, guard, shaft, motor, rotor, PCB, deep drawn body etc. will be interchangeable among various manufacturers. Interchangeability shall be checked by the firm and confirmed to RDSO. RDSO, if desired, will check the interchangeability of components.

M/s LEC We would request RDSO to provide use the various for components of various manufacturers to check the interchangeability of components. M/s Lucas TVS Shaft interchangeability is not advisable. Rotor assembly interchangeability is preferable provided all the suppliers are using bearing press fit on both sides and maintain the assembly dimensions in similar.

RDSO’s comments:

Interchangeability of fan components among various manufacturers at firms premises is not possible, hence deleted Modified clause

Clause deleted

Shaft Drg.

Shaft Drg. No. RDSO/PE/SK/TL/0153-2011 (Rev.1)

M/s Lucas TVS 37.5+0/-1 details on shaft is not clear. Radius profile/flat profile/depth details are missing.

RDSO’s comments:

It is 37.5+0/-1 from the centre of the counter on which the screw will rest . it is as an additional locking. Modified clause

No change.

NOTE: RDSO‟s comments are based on discussions during meeting dated 25.08.2015, accordingly final draft specification has been corrected..