Auto shut down (ASD)of HHP locos and action plan.

Review of Last three years Failure incidences indicate that mid section loco auto shut down (ASD) cases continue unabated. Details are given below:

ASD	2010-11	2011-12	2012-13	Total
Electrical causes	4	12	18	34
Mechanical causes	9	26	18	53
Faults not establiShed	17	6	10	33
Total	30	44	46	120

Analysis of causes:

A large number of factors either individually or jointly are responsible for ASD cases. These Factors responsible for Auto shut down of loco have been classified into two groups.

 Electrical causes :  Analysis of auto shut down cases reveals that major contributors from electrical side are AC Fuel pump motor failure(47%); FP relays ,RF contactor and EFCO switch(23.5%);Electronic cards(17.5%) ; cable and plugs(6%) and Radiator fan & others(6%).

Mechanical causes: The highest contributor from mechanical side is Engine Governor-24.5% followed by water cooling system-15%.

Other major contributors are Power assembly -11.3%, Turbo super charger -11.3%, Injection system-11.3%, Fuel oil system -7.5%, Lube oil system -7.5% ,cam gear clutch gear-7.5% and EPD-3.8%.

A significant number of ASD cases remain unresolved due to improper & incomplete investigation.  Root causes of failures were not establiShed in   27.5% of   ASD cases.

Action to be taken:

·        On arrival of failed loco in Shed, it should be checked as per check-sheet. (The copy attached).

·        Maintenance practices should be updated and trip schedule form should include Lube oil pressure  and Low idle RPM checking by sudden notch down of throttle, , measurement of  Governor Shut down gap , oil pressure and delay time of governor, TSC clutch drive performance test, fuel suction vacuum checking, OST value checking

by sudden notch up, Control circuit ground checking. Currently these tests are not being done by Shed.

·        ASD condition should be simulated in Shed and validation of corrective measures must be confirmed.

·        Performance of such measures should be further checked by conducting extended trails and footplates.

The check sheet has been prepared based on root causes of ASD cases reported in last three years. It should be further updated based on experiences gained by Shed in last five years after analysing all line and Shed ASD cases.

Implementation of above check-sheet and defects noticed should be closely monitored.

DA- Check list for auto shut down.

                                                                                         

   

Annexure

Checklist to arrest Auto shut down.

Mechanical causes	Action to be taken	Periodicity of Checking
1.Water shortage from Engine water cooling system and power pack-	a) joint checking with lab as per water leakage check-sheet: Leakages from pipe joints, Drain cock, Armour joints, Radiator core, Water inlet tube assembly, Water pump seal, Water filling pressure cap, Power assembly head to cyl gasket etc to be checked and arrested. b) Water contamination in lube oil to be checked for liner crack by lab. c) water pump performance to be checked by monitoring water pressure.	a) Leakage to be checked in trip and above schedule. b) trip and above schedule. c)30 days schedule
2. Lube oil shortage  a) Due to leakage and oil throwing and low lube oil pressure. b) Less lube oil viscosity.	a)Check Sheet for arresting lube oil leakage  in HHP locomotives issued to Shed vide L/No. Diesel/ Maintenance /HQS& Sheds/30 dated 26 July 2012 to be implemented. Lube oil pressure to be monitored and minimum lube oil pressure should not be less than 1.4Kg/cm2 at IDLE. Sudden notch up and notch down to check lube oil pressure during load test. b) Check lube oil viscosity and it should be 12.4 to 18.3 C/S.	a) Leakage to be checked in trip and above schedule. b) 30 days schedule
3. Governor a) Solenoid coil short or open. b) Oil leakage or shortage c) Drive shaft broken. d) Oil entry in Amphenol plug. e) Linkage failure that not coming back to original position after pressing in 2 seconds. f) Erratic RPM or IDLE RPM is less than 200 +/_ 4. g) Governor oil pressure less than 90 PSI h) Governor Trip plunger seized. i) Governor shut down gap is less than 33 thau. j) Governor Time delay is less than 50 Sec.	a) Checking of solenoid coil resistance in Amphenol plug to be done and provision of surge suppression circuit to be done. b) Topping up of governor oil without investigation to be stopped and checking for contamination, oil leakage as well as foaming to be done. c) DPT and alignment checking of drive shaft d) Traces of oil inside Amphenol plug to be checked e) Free movement of rack and linkage to be checked before starting the loco in all schedule f)Low IDLE RPM to be checked g) Governor oil pressure to be measured during starting. h) Movement of Governor Trip plunger should be checked. i) Shut down gap to be checked. j) Time delay to be checked with the help of cut off cock of water line connection to EPD.	a) & b) Trip and above schedule c)Whenever governor removed and during  3 yearly schedule . d) Trip schedule e) 30 days f) In all schedules g) 180 days and above schedule. h) All schedules. i) Special drive and 180 days schedule. j) 180 days schedule.
4.Cam shaft, cam gear bracket a) cam gear teeth broken ,bracket assembly of bearing of  cam shaft drive and block assembly bearing plane	a) To be checked by lab jointly	a) 6 yearly schedule
5.Turbo and clutch assly. a) Failure of clutch drive assly b) Turbo seizure c) Turbo educator assly jam causing positive pressure in crankcase	a)Clutch drive test to be conducted as given in EMD manual. b) TRD test and temperature monitoring to be done.TPU RPM to be recorded during load test. c) HQ instruction issued vide L/No. Diesel/ Maintenance /HQS& Sheds/30 dated 26 July 2012 to be followed . Crankcase vacuum to be checked and maintained  5 to 8 cm. of water in all schedule.	a), b) and c) 30days schedule
6.EPD and Hot oil detector. a) Malfunctioning of EPD and Hot oil detector	a) Overhauling of EPD and testing of both EPD and Hot oil detector.	a) 2 yearly schedule
7.Fuel system a) Suction vacuum in suction line is less. b) Suction line blocked or no fuel c) Fuel oil pressure <0.5 Kg/cm2 in any notch. d) Regulating pressure less e) Leakage of fuel in fuel system pipe joints	a) & b) Suction vacuum to be checked. c)& d) Fuel oil pressure monitoring and comparing with previous value. e) Leakage checking in all pipe line joints, filter housing.	a),b),c) and d) 30 days schedule. e) Trip and above schedule
8.Injection system a) Mechanical unit injector rack jam.	a) Checking of injector for free movements.	a)90 days schedule
9.OST a) Wrong setting of OST value	a) OST should be tested on test bench and performance of OST to be checked by pressing Gov linkage manually .Sudden notch up/down from idle to8th notch during load test to be done.	a) Test bench to be fabricated and to be tested in 6 yearly
10. Auxiliary  Gen. shaft breakage a) Mis alignment of Aux Gen drive shaft.	a) Auxiliary Gen drive shaft run out to be checked.	a) In 180 days schedule and all pass locos to be covered in priority by introducing special drive.
Electrical causes	Action to be taken
1.Control a) Computer power supply failure due to faulty PRG and PSM. b) Misbehaviour of DIO cards. c) Faulty DIP 80 card for MUX circuit failure. d) Water entry in ECC3 causing shorting of 823 C ,833B plug, TB 83 B and DIP card. e) Plug pin push back in 823 C ,833B plug and Amphenol plug.	a),b) and c)  Check for low voltage ground fault. Check PRG and PSM output, Digital I/O  for DIO and MUX circuit checking in EM2000.  d) Check door gasket condition and ensure door locks of ECC3 working properly. e) Ensure proper fitment at the time of plug fitment by checking solenoid output signal in EM2000 screen.   Card handling as per HQ instruction issued vide Diesel/Maintenance/HQS & Sheds/30 dated January 31, 2011.	a),b)  in trip schedule and c) in 90 days schedule. d) In every out going loco. e) Whenever maintenance of plugs carried out.
2.Switch and CB a) MUSD and EFCO switches failure . b) Short circuit  in circuit related to FPB, Control and Local control Circuit breaker. C) Malfunctioning of LWS	a) Multiple operation of switches and test bench test at section. b) Current measurement in Circuit breaker terminals. Ground checking C) Test bench test of LWS	a) & b) Checking in trip and above schedule and testing in test bench in yearly schedule. c) yearly schedule
3.Harness a) Low voltage ground may cause input circuit high	a) Control harness should be checked for ground. Special drive to be carried out to ensure protection of cable insulation with nylon spacers and sheet inside ECC1,2 and 3	a) Ground checking in 90 days schedule
4.Fuel pump motor a) Bearing seizure or inverter failure	a) Bearing temperature and unusual sound to be monitored. b)Fuel pump motor current trend  monitoring (Value should not exceed 7.8 Amp). If more than the rating value observed, it should be investigated.	a) & b) Trip and above schedule
5.Cooling system Radiator fan failure a ) Bearing failure b) Fan blade breakage. Rad fan contactor c) FCS tips brazing or interlock failure. d) FCF fail to pick up due to  armature jam. e) FCF coil open circuited. Fuse of RFC burnt or CB tripping. f) Radiator fan fuse burnt g) Radiator fan circuit breaker tripping h) Cable burnt and terminal lug loose or burnt.	a) Check radiator fan bearing unusual sound and monitor bearing temperature. b) DPT of fan blades c),d) & e) Cooling fan test through LCC check status of contactor for FCS contact brazing and inter lock failure as well as FCF contactor for armature jam and coil open circuit.RFC  test bench test to be done .Application of silicon grease. f) Fuse and RFC terminal checking for overheating sign. g) Check down load and monitor during load test. h) Cable checking for deteriorating insulation and overheating sign.	a) 30days schedule. b) 3 yearly schedule c),d) & e)Cooling fan test to be done in all schedules and test bench testing in yearly schedule. f) Trip and above g) Load test h) Trip and above
6.Relay failures a) Operating coil failure or Contact tips burning of SDR, FPM ,MCB and EFCO relays	a) Coil resistance checking and mv drop test. Relay maintenance instruction issued by HQ vide DSL/Maintenance/HQ/Shed/30 dated January 1st, 2013 to be implemented.       b) Parallel shorting of relays	a) 30 days schedule.