SMI

Alternator Go to - Cell , Plant

RDSO/PE/SMI/AC/0033 -2006 (Rev. O)

No. EL/1.6.9.15 Dated : 20-06-2006

SPECIAL MAINTENANCE INSTRUCTIONS FOR PROTECTION OF LEAD WIRE OF TL AND AC ALTERNATORS

1. TITLE :

Protection of lead wire in 4.5 / 25 KW alternator.

2. APPLICATION :

All makes of 4.5KW and 25 KW alternators used in BG, TL & AC self generating coaches.

3. OBJECT :

Large no. of failures of lead wire, coming from stator to terminal board, getting cut are reported by Railways. This was also discussed during 21^st MSG in May 2006. Detail instructions are covered in RDSO’s guidelines No. RDSO/P/G/0002-2005(Ver.0). However, salient features to be kept in mind to prevent failure, are circulated through this SMI.

4. INSTRUCTIONS:

(a) Lead coming from stator winding should be covered with silicon elastomeric coated fibre glass sleeve as per BS 2848 type 1/180 Tb, having a wall thickness of 0.9 mm. Size of sleeve shall be as follows:

For covering field wires of 4 sq. mm and 6 sq. mm, Sleeve with ID of 7 mm and 9 mm can be used. Sizes mentioned above (approximately) shall be suitable if lead wire is as per BS 6195-1993, type 5, voltage category C.

(b) Space between sleeve and bush in stator frame should be filled with RTV silicone sealant to prevent damage to insulation due to vibrations.

Anabond 666 or PIDISEAL can be used.

(c) Crimping of lug at the lead end should be done carefully to avoid any damage to the strands.

(d) Do not provide black adhesive tape over the lug, otherwise overheating due to bad crimping etc. cannot be detected in visual inspection. Provide transparent heat shrinkable polyolefin sleeve as per CLW specification No.CLW/ES/1-15/G for firm grip and ease of inspection.

(e) Sources for above items are the same as for Electric loco auxiliary machines approved by RDSO/CLW.

5. AGENCY FOR IMPLEMENTATION:

Carriage Workshop

6. PERIODICITY OF IMPLEMENTATION:

During POH or rewinding

7. REFERENCE:

(a)Guidelines No. RDSO/P/G/0002-2005(Ver.0) for rewinding of alternators.

(b)RDSO Specification of 4.5 KW /25 KW alternator. home

RDSO/PE/SMI/AC/0032-2006 (Rev. O)

No. EL/ 6.7.19 Dated : 31-05-2006

SPECIAL MAINTENANCE INSTRUCTION FOR LMLA CELLS USED FOR RMPU AC COACHES.

1. TITLE:

Monitoring and maintenance of 2V 1100 Ah LMLA cells

2. APPLICATION: RMPU coaches fitted with LMLA cells

3. OBJECT:

Newly developed 2V1100Ah LMLA cells for A/C coaches are being used in Indian Railways. These cells are of low maintenance feature and are designed to meet six month topping up interval during service.

To ensure the topping up frequency of six month and satisfactory performance, this SMI is issued.

4. INSTRUCTION:

(a) Proper initial charging is of paramount important for battery performance. At the end of initial charging of 75 hours cell voltage shall not be less than 2.60 V in three consecutive hourly reading and specific gravity shall be 1.240. If voltage is less than 2.60 V, the cell shall not be put into service and matter should be reported to manufacturer. Also make sure that cells were charged at specified current and initial filling gravity as mentioned in the maintenance manual.

After 12 hours rest, discharge @ 110 amps constant current shall be taken. Battery should give more than 11 hours of discharge till end cell voltage of 1.8V is reached. Finally charge the cells @ 110amps till three stabilised reading s are achieved.

(b) Ensure the voltage setting of Alternator /ERRU is as under for better performance and topping up frequency

130 Volt (shall be adjusted at 1500 rpm, half load)

(c) If Specific gravity of cells is less than 1.240 after train arrival, then Cells must be

charged @ 110 Amperes for 2 –3 hours.

(d) To check the six-month topping up interval initially battery should be topped up to green/ maximum mark of the float guide. During monthly inspection position of float guide shall be monitored. Water should again be topped up when the float reaches to red / minimum mark. Time interval for float to reach from green to red mark should be noted. If it is less than six month the matter should be reported to RDSO and manufacturer.

(e) If water consumption observed in all or few cells is more (interval is less than six month) check the following.

1 Over heating of few cells

2 Crack in lid or container

3 Leakage from vent plug or float guide

4 Poor sealing of cells i e. between lid and container

5 If water consumption is more in all cells without any of the above,

check and adjust the voltage setting as per Instruction (b).

(f) The cells should be charged every six-month with equalising charge rate as prescribed by manufacturer in the maintenance manual. This is required to bring the lagging cells at par with other healthy cells.

(g) To check the state of charge of cell in battery box the full coach load shall be put on battery bank for 5 minute and the close circuit voltage shall be monitored it should not be less than 108 V if cells are fully charged. At fan and light load only, the closed circuit voltage of cells shall be 112V. If voltage is found less then the above the cells should be charged (as per ‘c’) till the voltage of each cell reaches 2.6V with charger connected.

(h) In every annual maintenance schedule (POH) the cells should be charged fully with correct electrolyte level and gravity. After 12 hours rest, discharge at 110Amp. up to the 1.8 V end cell voltage. Well maintained cells shall give more than 8 hour duration till 4 years of service.

5. AGENCY FOR IMPLEMENTATION:

All the TL/AC depots and workshop.

6. PERIODICITY OF IMPLEMENTATION:

On condition basis.

7. REFERENCE:

SMI TL / 0025. home

RDSO/PE/SMI/TL/0030-2005 (Rev. O)

No. EL/ 6.9.9 Dated : 12.08.2005

Checking of pulleys in V belt drive.

1. TITLE :

Checking of pulleys in V belt drive.

5. OBJECT :

For effective power transmission from axle to alternator, health of pulleys should be good. Maintenance people should know when pulley requires change.

3. INSTRUCTIONS:

WORKSHOP

a) If bottom of the groove is observed shining throughout uniformly, the pulley should be replaced.

b) The pulley groove walls should be examined for ovality with the help of a steel scale. If the walls are worn out by more than 0.5 mm the pulley should be replaced.

c) Surface matching between pulley bore and shaft should be not less than 80%. The key in shaft should be fitted properly. Worn key must be replaced by spare EN8 key. If matching of 80% is done, key will not fail.

d) The angle of grooves should be checked by gauges. If angle has increased, the pulley should be replaced. There are different gauges for axle pulley and alternator pulley (See RDSO Drg. No.RDSO/PE/SK/TL/0087-2005 rev.0).

e) Replace rubber pads of axle pulley 100%. Check rubber quality in each lot from M&C lab.

f) Ensure gap between two halves of axle pulley to 3.0 ± 0.5 mm and tightening

torque should be upto 30 kg - mtr (maximum)

g) Life of pulleys is approximately 4 years. Date of replacement should be punched

on it as well as the alternator number on alternator pulley, as they are matched.

h) After removal of alternator for POH, gap between bogie suspension brackets should

be checked. Excess gap between bogie bracket and alternator suspension bracket

will lead to misalignment of alternator.

i) After fitment of alternator in the bogie suspension bracket, alignment of alternator and axle pulley should be checked. It can be checked by cord which should touch 4 edges of both pulleys simultaneously. It can be checked by laser beam also. Beam from alternator pulley groove center should fall in the center of corresponding axle pulley groove.

j) Do not paint the pulleys after cleaning. It will affect heat dissipation.

DEPOTS

a) Do not use repaired pulleys

b) Pulleys should not have any dirt/grime/oil traces

c) Replace pulleys if grooves are worn out by 0.8 mm depression on sides or bottom of groove is uniformly shining.

d) Ensure gap between two halves of axle pulley to 3.0 ± 0.5 mm and tightening

torque should be upto 30 kg - mtr (maximum)

5. AGENCY FOR IMPLEMENTATION:

All the TL/AC Depots & workshops of Railways.

6. PERIODICITY OF IMPLEMENTATION:

POH and 6 monthly schedule.

7. REFERENCE:

Workshop on alternators dated 17.11.1998. home

RDSO/PE/SMI/TL/0027-2004 (Rev. O)

No. EL/6.9.9 Dated: 5 .03.2004

SPECIAL MAINTENANCE INSTRUCTIONS FOR ‘V’ BELTS FITTED ONTL & AC COACHES

1. TITLE:

Checking of V belts in depots / workshops

2. APPLICATION:

All Train lighting and AC Coaches

3. OBJECT:

(a) It has been observed that ‘V’ belts are not giving satisfactory performance and not lasting POH to POH. It is very difficult to replace the belts frequently, if belts fail.

(b) The proper working of TL & AC alternators V- belts drive is essential to ensure reliable generation and proper load sharing between two alternators in AC coaches.

(c) In order to ensure proper fitment of V belts this SMI is being issued.

4. INSTRUCTION

(A) In order to check the new V-belts for proper fitment, following gadgets should be available at each depot/workshop for checking :-

a) Pitch length of V belt (as per appendix ‘A’)

b) Angle of V belt (as per appendix ‘B’)

c) Section of V belt (as per appendix ‘C’)

Few sets in each lot received should be checked.

(B) To get optimum performance following precautions should be exercised.

a) The belts of same nominal length i.e. same grading should be used as a set.

b) Two or more makes of belts should not be used in a set.

c) Check tension of V belt after fitment by tension gauge.

d) Re-tension newly fitted belts after 1^st trip or 500 km run, whichever is convenient.

e) Check alignment or pulleys whenever alternator is replaced.

f) Replace pulleys if grooves are worn out. Check by GO/NO-GO

gauges.

g) Measurement gadgets/gauges can be procured from OEMs

5. AGENCY FOR IMPLEMENTATION:

All C & W Workshops, TL & AC Depots and Production Units.

6. PERIODICITY:

Before commissioning of new belts on AC & TL coaches at PUs, workshops and whenever belts are replaced during normal maintenance at depots.

7. REFERENCE:

RDSO Specification No. ELPS/SPEC/TL/04 – June 1994

(H. Malhotra)

for Director General (PS & EMU) APPENDIX ’A’

home

APPENDIX ‘C’

SECTION CHECKING OF V-BELTS

GUAGE FOR CHECKING THE SECTION

Refer specification

Along a straight portion of the belt in an un-tensioned state, the cross-section of the belt shall be such that when placed in a guage as shown in above figure , it shall not touch the bottom of the guage, the edges of the top width ‘s’ and ‘t’ shall not be higher than the points ‘u’ and ‘v’ at the top of the template and the guiding mark ‘mn’ on the template shall cut the whole width of the belt in its upper half.

Note: The pitch width of the belt 19 mm, is the width of the guage at the level of this guiding mark mn, drawn on the gauge.

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