😡TROUBLE SHOOTING IN DIESEL LOCOMOTIVE😡
A considerable portion of road troubles are experienced due to some defects in electrical components and machines, which can be rectified with very little effort. In some of the cases they be temporarily attended to save the road failure of the locomotive. As the road troubles are faced by the supervisors/officers first on foot-plate, it would be very much helpful if they rectify the fault on road (temporarily or permanently) and avoid the stalling of rolling stock.
As the trouble shooting can not be really done without knowing their working etc.
1. TROUBLES
Road troubles may be classified in two categories :
1. Failure of component, which can not be rectified, but can be temporarily attended or by-passed to save or avoid a road failure.
2. Troubles due to accumulation of foreign particles like dirt, dust, etc, which leads to erratic or non-operation of the respective circuit and component. These faults can be rectified en-route, if they are pin-pointed.
Road troubles are experienced in three stages :
1. When the engine is dead and one driver is taking over charge.
2. Engine is idling, when driver is taking charge.
3. Fault or trouble is experienced while loco was hauling the load.
2. TROUBLES IN DEAD AND IDLING LOCOS
Normally when one driver takes charge of one locomotive at out-station, he gets the loco in engine idling condition, but sometimes locos are found in dead condition also. During checking of the locomotives, some troubles are faced. They are as under :
1. Engine can not be started
2. Some of the auxiliary machines are not running
3. Loco can not move (Not getting Power)
4. Loco starting with heavy jerk
5. Loco is moving but load-meter is showing zero or negative
6. Low Hauling Power
2.1. Engine not taking start
Before going to start the diesel engine, the driver is supposed to put on some of the breakers just to run some of the auxiliary machines and energise some circuits to make the fuel available to the fuel pump etc.
The switches and breakers to put on (STARTING SEQUENCE):
a) Close the knife switch
b) Put on the MB1 (Battery Breaker)
c) Put on the MB2 (Control Breaker)
d) Put on MCB1 & MCB2 (Master Control Breakers) fitted in the control stands - DMR should pick up
e) Put on MFPB1 & MFPB2 (Master fuel pump breakers) - FPC should pick up
f) Put on FPB (Fuel Pump Breaker)
g) Put on AFPB (Addl. Fuel pump bkr.) - Fuel Pump Motor should run and fuel pressure should run and fuel oil pressure should develop
g) Put on CEB (Crank case exhauster Breaker) - Crank case motor should run
Now engine is ready to take start
If any of the motors etc. are not functioning then the machines and respective wires etc. are to be checked according to starting circuit (Aux. Control Circuit)
2.1.1 Engine not cranking
To start the engine ECS to be kept in idle and engine start button is to push - CK1 & CK2 should pick up and engine should crank - if not check the interlocks in series with opt. coil of CK1 & CK2 namely, ESR4-N.C. (71-50T), ECS-close (50T-50C), P22-NC(43-43A), S1-NC (43A-43B).
If CK1 is picking up and CK2 is not then the interlock of CK1 (43B-43C) is to check for correct operation (it should make when CK1 is closed).
2.1.2 Engine cranking but shuts down with release of Start Button
If this fault is experienced, then it is clear that the condition mentioned in 1.1 is fulfilled.
The checking regarding this fault are :
a) Whether the lube oil pressure is building up or not, operation of OPS (oil pressure switch) can be checked by tthe stop of glowing of engine start lamp provided near the start button.
b) Water level may be inadequate or LWS (low water level switch) is defective - if LWS is in operated condition, then the alarm gong will sound both in idle and run position of ECS.
c) Tachometer generator may not be giving out put or taco-generator drive gear is worn out - Tacho-generator wires should be checked for proper connection etc.
NOTE In some cases if incoming driver stops the engine at 800c of cooling water temperature, then it takes excessive time to cool down (specially in summer). In that case also fresh driver (out
going) could not start the engine because the lube oil pressure does not build up as needed (2 to 2.2 kg/cm2) till engine cools down and viscosity of lube oil increases.
2.2. Not running of auxiliary machines and leads to non-starting of the engine as discussed above in 1.1
2.3. Loco unable to move (Not getting power)
This defect is related mainly with problems in propulsion control circuit, power circuit and excitation circuit.
2.2.1 Not getting power due to defects in propulsion circuit
After putting on the GF switch and notching up the throttle to 1st. notch putting the Reverser handle either in forward or reverse, the GF cont. should close. With the closure of GF cont. the traction generator should produce voltage and the power is transmitted to the traction motors to move the wheels. Cause of not getting power to be checked according to the sequence as follows :
2.2.1.1 Check the GF Contactor's operation
If not operating - Check BKT1-NC (6-6A)
ECS RUN (6A-6B) close
GR-NC (6C-6D)
TR-NC (6D-6E)
CK1-NC (6E-6F)
CK2-NC (6F-6H)
Maximum possibility of non-operation, however, may be due to welding of either CK1 or CK2 contactor. Sometimes TR interlock (6D-6E) also remains in open condition due to accumulation of dirt.
2.2.1.2 Check the operation of S1, S21 & S31 power contactors
2.2.1.2.1 S1 is not picking up - details of interlocks can be seen through diagrams.
Maximum possibilities - (i) Contact of ECS (8D-18A) should remain closed(ii) TR-NC (8E-8F)
(iii) P1-NC (8F-8M)
2.2.1.2.2 S21 is not picking up - (S1 picking up)
Maximum possibility - P21-NC (8M-8G)
2.2.1.2.3 S31 is not picking up - (S1 & S21 picking up)
Maximum possibility - P31-NC (8M-8G)
2.2.1.3 Position of BKTs and REVs is also to be checked
2.2.2 Power is not getting due to defect in power circuit
It is noticed very often that some of the power contactors through which electricity is fed to the traction motors do not operate due to defective magnet valves. Normally defective magnet valves can not be rectified en-route. However, bypassing one or more traction motors loco can be proceeded if possible. In such cases load meter may show or may not show. Power may also not be available due to wheel slip or power ground. Fault may be in the power circuit but the wheel sli[p and power ground will be described in separately.
2.2.3 Power not getting due to defects in Excitation Control Panel
The panel is to control the excitation of main generator. Normally the failure of the panel components / cards can not be rectified until there are separate cards available. However, it sometimes happens that two locos are failing with different reasons in one station or place. And if one loco is failing with some trouble in excitation circuit / panel causing no power, can be rectified replacing the cards taking from other loco.
a) It is advisable to replace all the excitation panel cards as a set to help the shed people in maintaining record. If any one becomes interested to identify the defective card, the cards are then to be replaced one by one and the result can be seen. Card 253 or 293 or 186 or 188 may be the defective one. Sometimes more than one card may also be found faulty.
b) Wire at FCP (field control panel) may get disconnected or burnt. FCP tubes are always hot. They should be allowed to cool down first and then proceed for repair. If it is clear that from which point the wire got disconnected, then they can be connected.
c) Sometimes BKR (braking relay) interlocks (22E-32D) and (32C-32D) do not make proper contact. They should be in closed condition during motoring. If there is any dirt accumulation, they can be cleaned.
d) LCP (load control potentiometer) in governor may not be touching with commutator and reference voltage increases causing low or no power.. Normally it is due loose brush arm mounting screw. However, before tightening the screw the commutator surface and the brush-arm should be cleaned thoroughly.
e) NO contacts of WSRs (10H-10T) also create this problem being closed. They should be separated if the concerned WSR is not operated.
f) If the exciter fails to generate voltage, Traction Generator does not produce output due to no excitation.
By checking the carbon brushes and connection on terminal board, its defect can be identified very often.
2.4. Heavy jerk experienced during starting the loco
Jerk is caused due to excessive 1st. notch current to the traction motors. The reason may be the following :(Remedial actions are also indicated)
2.4.1 GF interlock (61E-61EE) may be wrongly adjusted.
It should close when GF contactor is in open condition. If the interlocks are not getting closed properly, they can be rectified bending the finger. Sometimes they remain electrically separated due to accumulation of dirt. This fault can be rectified cleaning the contacts.
2.4.2 Defect in 188 card :
Due to sudden notching down, sometimes it happens that diode ERD20 & 21 get punctured (short circuited). It causes no current through suicide winding of PWM (pulse width modulator). By replacing this card with a healthy one the fault can be rectified. In this case availability of spare 188 card is the main factor.
2.4.3 Defect in other cards :
Card No. 253, 186, 254 may also create the problem of jerk. In all these cases by replacing the cards the fault can be rectified.
2.4.4 Current flow through PWM suicide winding may also get disrupted if the ER15 resistor inside control compartment gets open circuited and leads to jerk in 1st. notch. In such condition nothing can really be done en-route. It requires replacement.
2.5. Loco is moving but load meter is showing zero or negative
Load-meter indicates the current flow through traction motor no.1. S1 power contactor is related with this motor. If S1 does not operate or if there is an open circuit in the concerning circuits, then the load-meter may not show. But in that case full power (in fact the tractive effort) will also not be available.
In some of the cases due to ground fault in battery charging circuit or excitation circuit, polarity of main generator gets reversed and uncontrolled amount of current flows to traction motors in reverse direction. Normally jerk is also experienced during starting of train or locomotive. Engine also sounds unusually due to overloading. Load meter shows negative. To save the traction motors, loco should be stopped as quick as possible. However, the driver can proceed in lower notches with a close watch to the load meter and the shed people is informed for assistance. Fault in excitation circuit also creates this problem.
2.6. Low hauling power
In maximum cases, such indication is due to inability of the engine. However, due to defect or mull-operation of the circuits, sometimes, may cause such problems. By checking the rack movement at 8th. notch on load, cause of low HP can be pin pointed. If the rack movement is not maximum as specified (29.5mm in WDM2), then electrical may be held responsible. Of course in case of PG Woodward governor the argument will not stand because insufficient booster pressure or even wrong adjustment inside the governor may also force the rack not to move full.
If the rack movement is less than the limit in 8th. notch, then check the following :
2.6.1 In motoring condition, BKR contact 32D-22E should remain closed. Contact can be assured cleaning the contact tip.
2.6.2 Breakage of FCP wire may cause the same problem
2.6.3 Movement (unwanted) of LCP in PG Governor causes this problem.
2.6.4 If the LCP brush-arm of GE Gov. becomes loose, same problem occurs. The mounting screw is to be tightened then.
2.6.5 Exciter should also be checked for proper brush fitting etc. In case, if the brush sets of brush gear is found defective, one set from another brush gear can be taken out and fitted in the defective gear. One set of brushes per brush gear is allowed in case of emergency. One set from auxiliary generator can also be taken out and fitted accordingly.
2.6.6 Operation of WSR also causes no or low power, which is dealt latter.
2.6.7 Defects in cards :
Card 254, 293, 186, 188 may also cause this problem on certain defective conditions.
3. FAULT EXPERIENCED WHEN THE LOCO WAS MOVING
In maximum cases locos do fail in this condition, and it has been seen that because of nervousness or inadequate knowledge of the crew, the fault could not be rectified though they should have been rectified en-route with minimum effort.
The failures of this condition can be classified in following
categories :
3.1 Engine over-speeds
3.2 Engine not responding to throttle or speed is erratic
3.3 Engine hunting
3.4 Engine shuts down and crew unable to restart
3.5 Low HP
3.6 Engine bogs down under load
3.7 Operation of ground relay
3.8 Operation of wheel slip relay
3.9 GF not picking up
3.10 Operation of Power Contactors is erratic
3.11 Transition is picking up
3.12 Wheel slip indication in a particular transition
3.13 Hot engine indication
3.14 Battery charging stopped
a) No oil in Gov. Hence Top up (In case of emergency only fuel oil can be used in PG Gov. and in GE Gov fuel oil and crank case oil with a ratio of 2:1 can be use.
b)Gov. Amphenol plug loose Tighten.
c) Tacho gen. wire broken Connect
d) Wire form ECP broken Connect
4.13 Hot Engine indication:
It is experienced in summer season to the maximum extent. Normally locos do not fail en-route due to hot engine. But if the locomotive is equipped with ETR, the diesel engine comes to IDLE after ETS operation. As the viscosity of lube oil goes down with increase in temperature, due to sudden fall in engine speed, the lube oil pressure drops below the drop out setting pressure of OPS. As a result engine shuts down and could not be restarted, till the temperature of the diesel engine comes down, and the viscosity of lube oil goes up. Normally most of the sheds bypassed the ETR so that after operation of ETS, engine speed does not drop to idle. Driver gets the audio-visual indication only. Getting this indication, driver should notch down to 6th. notch or so and slowly pass the blocked section. The alarm gong will go on sounding. As soon as he reaches the next station, he should notch down to 3rd. notch and not to IDLE. GF switch should be put off on 3rd. notch itself, so that the lube oil pressure is maintained at its safe value. After putting off GF, he should start FAST PUMPING. In summer, if engine gets shut down causing low lube oil pressure, it normally takes 1 hour or more to cool in a state when radiator fan does not work, and leads to loco failure.
4.14 Battery is not taking charge: (B.A. showing discharge)
It indicates failure of Battery Charging Circuit. Proceed to check the cause as follows :
1) Check VRP fuse----Renew with spare if doubtful
2) Check AGFB------ Reset if tripped.
3) Check VRP base for loose or cut wire-----Tighten/connect
4) Check Aux. Gen. brush gear and brushes------ Attend/replace as required.
5) Check BX-BN Card for proper placement ------Cards should be placed properly, after putting off AGFB.
operation operation may be during engine starting such ground fault is commonly known as starting ground and is difficult to rectifier without adequate facility into the Loko may be allowed to run with this world but if it is a power ground floor ko V fails possible if not rectified first check it with the explosive or not explosive
explosive from men generator dirty commutator brushes are strictly inside pockets pigtails work out of brass and touching ground foreign particle on computer if from power contactor metal deposition inside our cute check the source clean surface with 007 paper polish The Princess cut the pistol and throughout throw it out
from power contactor metal deposition inside org cute replace with parallel contactor are cute Logon suit run at Slow speed so that parallel conductors do not operate sledges operation of power contactor disconnecting the magnet ball on or two Motors maybe by past if the load permits foreign particles throw it out if from traction Motors commutator dirty unit broken or sticky carbon brush attend a turbo generator foreign materials do from FS contractors to be attended as power contractors accepting magnet valve operation
non explosive with knowledge of power circuit can only rectify this type of ground fault with adequate facility Mega I am it is however some effort Steel can be made to find out the faculty member and if possible is stated below
foreign material inside main generator traction motor BKT reversal PC apps contact a w s r a w s r fcp throughout the foreign material any broken wire touching ground if possible isolate or cut out the piece traction motor cable rubbing with motor care and the insulation is damaged but separate them and being with trophy so that rubbing divided
first locate which relay is getting in organised and at what speed to understand the motor combinations (translation 30 km first edition 1 hour some of the FS conductor spot welded separate them manually also cleaned the tips w SR1 an equal current flow in TM number 1 and 4 check pkt-1 rivers 1 and 7 for proper operation try to make them ok manually if any fault is noticed WSR to an equal current in TM number 2 and 5 check BKT to rev1 and s31 for proper operation attend as above ws3 an equal current in TM number 3 and 6 check BKT 1 rev1 and as 21 for correct operation attend as Above All the railways are operating wsrr open circuited connect the broken wire if possible note in some of the cases due to break binding from adjustment of slack adjuster in educate brake cylinder travel oil dropping on particular wheel etc will sleep is experienced they are also to be checked also in case of opinion sleep same will sleep indication will be experienced and can be found out on checking only
experienced at speed range of 30 kmph to 47 kmph aur at 30 km is only one or some of the FS contractors are not operating FS 22 23 24 and 26 not operating check for mechanical blocking check broken wire of property will check check fs21 interlock operation for closet during operation check broken wire from of ITI coil and interlock wheel slip at a speed of 47 km per hour and above ws1 operating either p2r P31 not operating check leakage on magnet walls WSR to operating either p22 or P32 not responding ws3 operating either one or p21 not respond operating other than these if any of the six Motors not defective to Motors can be isolated and Loko can be Run with 4 motor in that case S1 Rs 21 or 31 can be made putting wagered pages inside concerned magnet war following chart will help to locate the concerned contractor for any motor with different WSR operation
Finding out a faulty motor
Say, in one locomotive, in series parallel circuit (0 to 47 Kmph) WSR1 is getting operated. S1 magnet valve is to be disconnected or wedged first. If load permits, train speed increase. Transitions will take normally. But when it will attain a speed of 47 Kmph. and second transition will pick up, wheel slip will again be experienced. Check the relay getting operated. If WSR1 is getting operated again, then TM1 is faulty. Disconnect or wedge P2 magnet valve. Above 47 Kmph, the locomotive will run with 5 Motors. If WSR3 operates during parallel transition (above 47 Kmph), isolate TM4 wedging or disconnecting P1 magnet valve. This type of isolation helps in Mail/Express services, where loco runs with lesser loads
GF not picking up PCS can broken unable to put ECS in Run short circuit 6a 6b all run contact should be sorted opening ideal contacts Jiya 6b 6c open make it close tr6 d60 open shot the contact CK one or ck2 welded get then separated make sure that she ke 1668 and cck2 GF 6hr told sometimes due to wrong fitting of CK one or two are its causes this problem GF switch defective both GF features cannot be effective at a time find out the defective and short circuit with both the switch should not be sorted GF contactor should not be closed with age which because it would give jerk in first note operation of PC
GF not picking up PCS can broken unable to put ECS in Run short circuit 6a 6b all run contact should be sorted opening ideal contacts Jiya 6b 6c open make it close tr6 d60 open shot the contact CK one or ck2 welded get then separated make sure that she ke 1668 and cck2 GF 6hr told sometimes due to wrong fitting of CK one or two are its causes this problem GF switch defective both GF features cannot be effective at a time find out the defective and short circuit with both the switch should not be sorted GF contactor should not be closed with age which because it would give jerk in first note operation of PC
operation of PCR erratic it is dependent on magnet wall operation find
out the faulty contactor and operated manually by wedging respective
method wall are bacha if it appears then check the circuit if given S1
not operating bkr SC AT&T NC open is it D18 Run or p18f it m.n.c.
open make them close for Clean contact s21 not operating but as one
operating p218 M at z n Si open s31 not operating S1 and S2 1 operating
EP 318 M at GNC open P1 P2 1 and 31 not operating as 318 l8s NC open P2
not operating p22 and P32 operating as 18 ke at you NC open p22 not
operating P2 and P3 to operating s21kw NC open P32 not operating p2a and
p2p to operating S3 e18 k8 wnc open p2p 22 and P32 not operating GF at
held at r&c open or excessive gap of p2188 ke and adjust get not
more than one by attained and ensure proper operation sometimes
reversioner magnet bol do not operate due to loss of contact in control
stand in that case driver should work from other control stand driver
should also try to operate from other control stand in case of any
trouble experienced in controlling engine speed
transition is not picking up first transition not picking up operation of 6 FS corporate 10 tractors is in the indication of first transition but to operate them was our must not operating close P 266 VNC close as 216 vcw and close tr6 666 and see it not still not working operate effects are usually because what is inside first 210 card fsr picking up but VFS contact us or not picking up clean fsr 619 edge and no contract can also be changed with spear fs21 and FS 25 are operating rest or not operating fs21 1319 jeno is to be cleaned and broken wire it is to be connected second transition not picking up operation of 6 parallel conductors is in the indication of second transition for their operation TR must operate we are not picking up hot inside S 210 card operate TR manually if manual switch is there use it TR operating but PC not operating clean and make TR no I know contact at me at l parallel pieces are operating but GF not picking up make sure that P32 cc6 eno is closing adjust if required third transition not picking up operation of a conductor is the indication of third transition effects are not operating clean and make tr6 v6x and no contact if stihl FS are not picking up defect is in third 210 card
4.12 Wheel Slip Indication: - Covered in 3.8 in details.
4.13 Hot Engine indication:
It is experienced in summer season to the maximum extent. Normally locos do not fail en-route due to hot engine. But if the locomotive is equipped with ETR, the diesel engine comes to IDLE after ETS operation. As the viscosity of lube oil goes down with increase in temperature, due to sudden fall in engine speed, the lube oil pressure drops below the drop out setting pressure of OPS. As a result engine shuts down and could not be restarted, till the temperature of the diesel engine comes down, and the viscosity of lube oil goes up. Normally most of the sheds bypassed the ETR so that after operation of ETS, engine speed does not drop to idle. Driver gets the audio-visual indication only. Getting this indication, driver should notch down to 6th. notch or so and slowly pass the blocked section. The alarm gong will go on sounding. As soon as he reaches the next station, he should notch down to 3rd. notch and not to IDLE. GF switch should be put off on 3rd. notch itself, so that the lube oil pressure is maintained at its safe value. After putting off GF, he should start FAST PUMPING. In summer, if engine gets shut down causing low lube oil pressure, it normally takes 1 hour or more to cool in a state when radiator fan does not work, and leads to loco failure.
4.14 Battery is not taking charge: (B.A. showing discharge)
It indicates failure of Battery Charging
Circuit. Proceed to check the cause as follows :
Check VRP fuse Renew with spare if doubtful.
Check AGFB Reset if tripped.
Check VRP base for loose or cut wire Tighten/connect.
Check Aux. Gen. brush gear and brushes. Attend/replace as required.
Check BX-BN Card for proper placement. Cards should be placed properly, after
putting off AGFB.
Summary
Troubles experienced by the driver or other inspectors travelling in the footplate both in dead and idling locomotives have been dealt in this unit. What could be the probable reasons of troubles and how the trouble shooting should be done have been described in the form of charts. It is expected that this unit would help the officials in footplate to rectify the fault without taking assistance of maintenance people.
The reasons of road failures e.g. engine not taking start, not getting power, low hauling power, load meter showing zero, transition trouble, jerk in first notch, etc. which contribute about 70% of the electrical failures, have been described in this unit. Identification of probable areas, which normally go wrong, would help the Railway in minimising detentions, if appropriate actions are timely taken by the officials on footplate. There are some defects, which, perhaps, are difficult to rectify en-route, without proper assistance and spares, have also been incorporated in this write-up.
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