Trouble Shooting

TROUBLE SHOOTINGQ: Smoke from the exhaust is a mirror of the combustion chamber. How can faults be

detected from the nature of the smoke? Discuss briefly.Turbo smoke analysis

A healthy engine will give colourless, odourless smoke. Black smoke means incomplete combustion. Grayish blue smoke means lube oil burning in the combustion chamber. It indicates

more valve-valve guide clearance, defective oil rings, ovality in liners. White smoke means water ingress in combustion chamber. Cracked cylinder head or

bursting of after cooler tubes may be the cause. A flame from turbo means air starvation either due to choked air filters, defective TSC

or completely choked after cooler. Intermittent puffy black means dribbling nozzles. If the smoke is clear in lower or higher notches and not in intermittent notches, it means

that the notch wise horse power distribution is not proper.Crank case smoke analysis Black smoke means poor blow bye i.e., gases are going in the combustion chamber. White smoke means water leakage in crankcase. Grey smoke means piston or main bearing likely to seize. Flame means a piston or bearing is already seized.

Q: The driver has booked repairs in a particular locomotive. What action would you take in the shed to rectify following problems.

1. Hot engine/All water drained.2. Fuel pressure dropping.3. Engine shutdown due to low lube oil pressure.4. Hauling power poor.5. Power ground on every notch6. Wheel slip on all notches.7. Engine shutdown automatically without indication and could not restart.8. Battery showing discharge/Over charge.9. Loco giving jerk on First notch and load meter showing excess current.10. Engine not cranking.11. Load meter showing zero/Loco not moving in either direction/Loco not responding to

throttle.12. Fuel dilution.13. MR Pressure dropping.14. Expressor Needle valve not lifting up.15. Wheel skidding.16. MR Pressure not building up.17. Inter cooler safety valve blowing.18. MR Pressure dropping after unloading.19. MR Pressure increasing more than 10 Kg/Cm2 and MR safety valve is blowing.20. Inter cooler pipe/LP head running hot.

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Supervisors’ Training Centre/Kharagpur.

21. HP head/HP pipe running hot.

1) Hot Engine/All water Drained.

Check water level in Expansion Tank. Check working of Radiator Fan. If not working, then check whether.

- Universal shaft is broken.- ECC foundation bolts have worked out.- ECC bearing is seized.- ECC coil is open or short – circuited.- Carbon brush size of ECC is condemned.- There is a supply to ECC wire no:72 and 4.- R1/R2 defective or there wiring burnt.- ECC coil resistance is as per manual.

Check ETS setting. It should be ETS-1 = 64ºC, ETS-2 = 68ºC, ETS-3 = 90ºC. Pressurization of cooling water system is working or not. If not whether the following

is one of the reasons.- Water filling cap missing or not fitted properly.- Defective pressure cap assembly.- Welding of pipe crack.- Over flow pipe not dummy.

Carry out cooling efficiency test to see the functioning of the radiators. It is the test to check the time taken to bring down the temperature from 90ºC to 68ºC the time should not be more than 5 minutes.

Check the gaps in radiator compartment. Check radiator fan RPM – it should not be less than 1150 RPM. If the RPM is less, then

check coil resistance, condition of outer drum and air gap between outer drum and rotor.

Check the condition of radiator fins – whether damaged or good. Whether the radiator is choked or not. Check water pump pressure at 8th notch. It should be between 1.8 to 2.2Kg/Cm2, but if

it is less than 1.8 Kg/Cm2, then either the water makeup pipe is choked or water pump is defective or impeller nut of water pump is worked out.

If no defective occurs, check exhaust temperatures at load box. Some times the water leakage can also be seen only during load box.

2) Fuel oil pressure dropping.

Check fuel oil level in the fuel tank. Check the working fuel booster motor. If not working, then check

- Condition of commutator - Carbon brush seize and breakage.- Oil ingress.- Supply in FP motor in wire no. 71 and 4.- Fuel circuit breaker is OK, defective or tripped.- Fuel pump contactor is energized or not.- Conditions of wires.

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Heavy leakage of fuel oil in the system from a particular location. Whether fuel oil is contaminated with water. Chocking of suction line with foreign material. Check the fuel booster pump vacuum. Fuel pump coupler is free/OK/jam. Is their any air lock in the system. Primary filter or secondary filter is OK/Chocked/Collapsed. Check the setting of relief and regulating valves.

3) Engine shutting down due to low lube oil pressure.

Check lube oil level. Condition of lube oil filter housing drain cock and lube oil strainer drain cock. Check water contamination in lube oil, if yes the sources of water contamination. Check fuel dilution. If yes, what is the viscosity and the source of dilution. Check lube oil pressure at 90ºC. Check lube oil pressure on easing throttle from 8th notch to Idle. Idle RPM – normal as well as easing throttle at 90ºC. Setting of OPS in GE governor Locos – pickup and drop-out values. Lube oil pressure at the inlet of Wood Ward Governor at 90ºC at Idle as well as 8th

notch. Check leakage in the system if yes, location of the leakage. Check gauge pipe for choking. Setting of Relief and regulating valves. Pressure at outlet of Lube oil pump at 90ºC, at idle and 8th notch. Condition of lube oil filters. Condition of S-Pipes for leakage.

4) Poor hauling power.

Carry out dry run and see the rack position. Also check the condition of rack linkage and pins.

Note down the following parameters :- - Engine RPM at Idle and 8th notch. Idle RPM – 400 and 8th notch RPM 1000.- Note down tacho generator output voltage (42 – 45 V at Idle and 105 to 110

V at 8th notch) and reference voltage (24.4 V) at Idle and 8th notch.- Reference current – at 8th notch, it should be 30 Milli Amps for WDM2.- No load voltage – at 8th notch, it should be 685/770 V. If NLV is less, then

check card no.188, 254 and 292. also check ECP and excitation panel. The tightness of connections of various terminal lugs & studs to be checked. If NLV is not building at all, then check.

Exciter armature for proper rotation. Measure main field resistance. Condition of internal connections and exciter terminal connections. Exciter carbon brush size and breakage. Check traction generator/Alternator and record main field resistance. Also check the

condition of main field connections.3


Check and record Turbo run down time. In case of Wood ward governor, check position of LCP. Is there any leakage of exhaust gases from exhaust manifold? If yes mention location. Is there any leakage of air from after cooler? Check after cooler dummy plug – whether

intact or not. Condition of cyclonic filters or oil bath air maze filters. Carry out blow bye test and identify defective assembly. Check tappet clearance. If not proper, remove cylinder head and check for breakage or

bending of inlet and exhaust valves. Check condition of yoke/yoke guides/pushrods. Check valve timing. If nothing is found, do load box and record following.

- Compression and firing pressures and identify locations with less pressure.- Current and Voltage at 8th notch.- Rack opening.- Position of LCR.- Leakage of air and exhaust gases. Leakage from air inlet elbows, block to

after cooler gasket and air maze filter to after cooler gasket can be checked.- Exhaust temperatures.

In case all the above checks or ok and still the HP is not developed, inspect split gear. If on off load rack opening maximum, replace thirty after cooler which may be choked.

5) Power ground on every notch.

Start the engine and race it by putting both GF switches in ON position and see whether it is Non-Explosive power ground.

In case of Non-Explosive power ground, shut down the engine and record the I.R. between power circuit & earth, between control circuit and earth, between control circuit and power circuit and between power circuit and earth.

If I R is zero or low between control circuit and earth, it indicates either any component or wiring in the control circuit is earthed. Identify the component and location and rectify the same.

After removing the earth fault in control circuit, check IR of power circuit to earth. If is still zero/low, proceed as under-

- Put both BKT/REV in neutral and check IR between power circuit and the earth.

- If there is no signs of improvement, check IR of all main fields of Traction motors from FS contactors.

- If IR of one or more FS contactors is low/zero, disconnect F & FF cable joint of that particular Traction Motor and check IR of carbody and Traction Motor cable.

- If IR of carbody lead is zero, check concerned FSPR, main contactor on REV2/REV1 and bus bars for any leakage path. Rectify the cause of low IR.

If IR is still zero/low, check carbody cable for rubbing/discharged insulation. If IR of Traction Motor leads (F&FF) is zero, clean the traction thoroughly with dry

compound air and proper cleaning agent. If IR is not improved, connect the cables in 4


normal way and put the loco on dynamic braking and checking IR after every half an hour. If still IR does not improving replace the motors.

After putting BKT/REV in neutral, if there is no improvement. Disconnect –ve leads (GA-2) from traction generator/alternator terminal and lead no. A1, A2, A3, 19 20 and 21 from ACCR. And record IR of power circuit. If IR is OK, Then check the IR of traction motor armature cables from control compartment. Also check the condition of cables and joints sleeve and bus bars. Also see whether the cable is properly positioned in wooden sleeve.

If IR of motor side lead of one/more cable is zero/low, then check oil/water ingress in traction motors and IR of armature & interpole of relevant motor.

If IR of interpole is zero, clean the motor with dry compound air. In case armature IR is zero, check the condition of the commutator, V-ring, carbon brushes for the free movement and breakage, armature winding and bearing.

If IR of Traction Generator/alternator is zero/low, record IR of armature and interpole. If TG armature IR is zero, check condition of armature, accumulation of dust and oil,

winding, V-ring and PTFE sleeve. If interpole IR is zero, check IR of brush holder assembly and their insulators. If OK,

then improve IR by air blowing through dry compressed air and hot air blower. In Traction alternator, check IR of Stator and Rotor. Also check oil ingress, power

diodes, flashing of heat sink, rectifier unit, etc. Check WSRR and WSR1, WSR2, WSR3 for defects.In case of explosive power ground, check for signs of flash-over in traction generator, power contactor tips and traction motors. Check operation of power contactors & FS contactors. Check interlock gaps, pick-up & drop out contactors ۠

6) Wheel slip on all notches

Go through the repair book and see whether the wheel slip is of temporary of permanent nature.

See the position of MCOS. If it is isolation position, check the relevant traction motor and its circuit thoroughly.

If MCOS is in “All in” position. Start the engine and record millivolt drop across the coils of wheel slip relays in both directions and locate the defective traction motor. WSR1 WSR2 WSR3 2S3P 6P

If any abnormality is noticed above, check relevant traction motor, REV/BKT, power contactor, bus bars.

If MV is abnormally high during 2S3P combination, check WSSR for loose connections, broken thimble, open circuit and loose clamps. Check relevant bus bar of BKT/REV for breakage/loose joint.

If MV is high in 2S3P as well as 6P combination, check the common traction motor, REV/BKT and bus bars. Also check cable connection joint of that traction motor.

If wheel slip is taking at 26 KMPH I.e., 1st transition (As recorded in repair book), check all the FS contactors for their welding tips, operating coil, open circuit or supply not coming. Check FSPR and relevant cables for damage/burnt/overheating.

Shut down the engine and check-

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- for cable lug terminal burnt, IP/main field burst and cut marks on the cable and pinion slack.

- Check BKT/REV for presence of any foreign material, burnt/improper/non contact matching of main contacts, breakage/burnt/loose joint of bus bars, etc.

Measure MV drop across power contactors. Specify the location having abnormality (More than 100 in series and more than 50 in parallel)

7) Engine Shut Down automatically without indication and could not restart

Check the loco in dead condition for the following-- Governor oil level and leakage.- If less top up the oil.- Tripping of OST. Reset, if tripped - Check fuel rack movement. If not free, check fuel linkage pin.- Lube oil level.- Water level in expansion tank.- Battery condition- OK or run down.

If the loco is fitted with GE/EDC governor, carry out dry run test. If it is not taking place, check for stabilizing action, if stabilizing is not taking place, check:-

- Governor pressure.- OPS interlock between wire no 71-50F.- CK2 NC interlock between wire no 50P-50N If stabilizing action is taking place but engine is not starting.- Check the supply at the governor terminal wire no 2 & 3 if supply is

coming the governor clutch coil should energize. If not energizing, it indicates some problem in the governor. If supply is not coming check supply at the pin no. J of governor am phenol plug.

- If supply is coming at J pin and not coming at the terminal at governor clutch coil, it indicate some problem in the harness of governor.

- If supply is not coming at pin no. J of governor am phenol plug check the supply at terminal if wire no. 50J & 4 on back panel.

- If supply at terminal at wire no. 50J on back panel is not coming, check LWS (50D-50J) if not OK, check start switch (71-50D) if it is not OK, check OPS 971-50K if it is not OK, then check SAR interlock between wire no. 50D-50K.

If loco is fitted with Woodward governor Remove governor am phenol plug and start the engine if the engine not starting,

governor base or governor itself is defective. If engine starts in normal way after removal of am phenol plug, check supply at ERR

(3-3A), if coming check the position of MUSD on both control stands Check CPR-6 and replace it shorted.

8) Battery showing discharge/overcharge

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Start the engine and check battery ammeter. If showing overcharge, check BN/BX cards.

If BN & BX cards OK and battery ammeter is still showing overcharge, check auxiliary generator output voltage. If more than 72±1V, adjust it.

If unable to adjust AG voltage, check VRP baseIf battery ammeter is showing discharge, check

BN card, BX card and VRP base Check VRP fuse Check AGFB-whether ON/OFF. Check AG output voltage Check terminal connection in the terminal box of auxiliary generator –

overheated/burnt/OK. Check terminal connections on back panel TB having wire no. AGA1, AGA2, AGF1,

AGF2. Check wiring of auxiliary generator between Aux. gen. and back panel terminal

whether short circuit or open circuit.

9) Loco gives jerk on 1st notch and load meter showing excess current

Start the engine and check Reference voltage and Exciter Voltage. If the reference voltage is zero or less, check Governor LCP and brush arm. If not OK,

get it rectified. If reference voltage is OK and exciter voltage is high, check

- GF NC interlock between wire no. 61E-61EE.- ER-15 wire wound resistor resistance.- Wire no. 34 on ACCR.- Wire no. 36 on traction generator –ve terminal.- Card no. 258 & 188.- Connection on ACCR.- Resistance of ACCR; working of AC and DC.

If load meter is showing excess current, but loco is not giving jerk, check LAS.

10) Engine not cranking

Check the battery condition. If it is not OK, then check whether- Battery is run down or not.- One or more cells are dead or battery terminal is burnt. In such a case,

replace the defective battery/jumper lead. In case, the battery is run down, start the engine by having a parallel jumper from the

battery of another loco and check for battery charging. In case the battery charging is not taking place, check VRP fuse.

If VRP fuse is blown OFF, replace the fuse. If battery charging is still not taking place, check VRP cards BN/BX by replacing them one by one.

Even then if the battery charging is not taking place, check whether battery knife switch is closed or open. MB1/MB2 and MFPB1/MFPB2 are ON or OFF. Also see whether FPC is energized or not. If it is not energized, then check supply at the coil (Wire no. 13 and 4). If supply is coming, but FPC is not energized check its coil.

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If the defect is still not found, press the engine start button and check CK1/CK2- whether these are energized or not.

If CK1/CK2 are not energized, check the supply at their coils. If the +ve supply is not coming at the coil, check interlocks ESR4(NC)_71-50T ECS(Idle)-50T-50C Start push button(NO) – 50C-43. P-22 (NC) – 43-43A S-1 (NC) – 43A – 43B Check these interlocks and rectify and ensure that supply is coming through these interlocks If CK1 is energizing but CK2,ensure that CK1(NO) interlock between wire no. 43b-43

closes when CK1 operates and current is passing through this. If –ve (Wire no. 4) supply is not coming, check –ve loops or magnet valves of EP

contactors (PC/REV/BKT) and ensure that these are in perfect order. If CK1 and CK2 are energizing, but engine not cranking. Check-

- Starting field and cables of Traction Generator for burnt/overheated terminal lugs and damaged cables.

- If TG and cables are OK, check diesel engine by manual cranking. If the crankshaft is not cranking manually, check diesel engine thoroughly and record observations.

11) Load meter showing zero/loco not moving in either direction/loco not responding to throttle.

Examine the loco and if one load meter is not showing, replace defective load meter. If both the load meter are showing zero with loco not moving, check picking up of

power contactors and GF contactor. If GF contactor is picking up, check NLV. If GF contactor is not picking up, check supply at the terminal of GF contactor.

- If supply is not coming, it indicates that operating coil is either open/short circuited.

- If supply is not coming, check whether +ve or –ve.- If –ve is not coming, provide a parallel loop.- If +ve (6H) is not coming, check interlocks. CK2(NC)-6F-6H

CK1(NC)-6F-6E TR (NC)-6E-6D

BKR(NC)-6C-6D GR(NC)-6C-6B ECS(RUN)-6B-6A BKT(Motoring)-6-6A Ensure power contactors.- Check both control stand GF switches.- Check master Controller interlocks.

If GF contactor is picking up, but power contactors are not picking up, check-- BKT – they should be in motoring position.- REV- they should be in desired position.- Main shaft of BKT/REV for breakage.

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- Check the fallowing interlocksP1(NC) – 8FF-8MMCO(All in) – 8F-8FFTR(NC) – 8E-8FBKT(NC) – 8AA-8EECS(RUN) – 8D-8AABKT1(NC) – 8C-8DBKT2/BKT3 – 8C-8AREV/REV2 – 8A-8

- If series contactors are not picking up, but parallel contactors are picking up by putting TR by-pass switch in ON position, check TR(NC)-8E-8F, MCO(all in)-8F-8FF and P1(NC) – 8F-8M

- If no defect is found by above trouble-shooting, check control air pressure. It should be 5 Kg/Cm2.

In case, GF contactor and power contactors are picking up, but still the load meter is showing zero & loco is not moving, check NLV

- If NLV is not building, check the reference voltage. If reference voltage is high, check governor LCR and brush arm. If defective, replace,

- If LCR and brush arm are alright, check harness.- Check the reference current. If it is zero, check BKR interlock (22E-32D). If

interlock is OK, check card no. 186, 254, 188 and 293 for defects.- Check excitation panel, VDP and FCP.- If exciter output is not coming at all, check exciter for broken armature

shaft, main field for open circuit and carbon brush for size.- If on locos fitted with Woodward governor, reference voltage is high, check

governor LCR position. If it is in minimum position, rectify the same.

12) Fuel dilution

Record viscosity. If it is less that 120 cst, do not start the engine. - Remove the injectors and test for crack/dribbling nozzle.- Remove the tappet cover and check for excessive tappet clearance.- Check cylinder head for valve-bent or broken.- Bent push rod and broken yoke/yoke guide.- Carry out blow bye test and indicate location having less blow bye.- Indicate air going in TSC or in engine sump. If air is going in TSC, check

for broken/bent valve of cylinder heads. If it is going in the engine sump and blow bye is below 0.5 Kg/Cm2, remove power assembly and check for broken piston, seized piston or rings in one line.

Change oil and increase viscosity of the lube oil. Start the engine and check that all cylinders are responding. If the cylinder is not responding and abnormal sound is noticed from any location, check for damaged roller and cam.

In case the viscosity is more than 130 cst, start the engine and check each cylinder is responding as per above procedure.

Check TRD. Check for valve timings. If nothing is found, check for cracked fuel gallery.

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In case nothing found still, carry out load box and record firing and compression pressures. If it is less the fuel is not burning completely and the fuel oil is going into the engine sump through piston rings

In some cases, fuel dilution also takes place due to loose split gear as it disturbs valve timings.

13) MR pressure dropping Check whether MR drain cock or J-Filter drain cock is open or closed. BP, FP equalizing pipes of brake cylinder and MR equalizing pipe are open/closed. Check external leakage from:-

- Air brake valve and ABD valve.- BP, FP, MR equalizing pipe, brake cylinder equalizing pipe.- Intercooler tube.- HP discharge pipe LP discharge pipe.- Air cooling pipe.- Air pipes in the nose compartment.- N1 reducing valve pipe/drain cock.- Green glass filter.- AC governor to ABD valve filter.

Intercooler safety valve is intact or not. Is it blowing continuously? If yes, check unloaders of LP and HP and discharge valves.

Check whether loading/unloading is taking place of not. If no, adjust, LP, HP and AC governor.

MR safety valve is intact or not. MR safety valve is blowing at low pressure or not. If yes, replace. Check if LP is throwing air. If yes, check LP unloader. Check LP/HP valve plate breakage. Check sizes of valve plate. It should not be less

than 0.038”. Check LP/HP pistons for seizure/breakage. Check if MR pressure drops after applying the brakes. If yes-

- Bogie equalizing pipe.- Bogie cut out cock pipe.- Brake cylinder S-pipe.- Brake cylinder.

If loco is fitted with EPG governor switch, check setting of governor switch. If not OK, check

- Supply at governor magnet valve.- If not OK, check continuity of wire no. 25 between governor switch and

magnet valve.- If OK, check toggle switch- If supply is coming at governor magnet valve, but loading/unloading is not

taking place. It indicates magnetic valve is defective.14 Expressor needle valve not lifting up Check oil level. If adequate oil is not visible, check condition of glass. Add oil and start the engine. Check whether needle valve lifting up properly or not In case of needle valve lifting properly, check for oil throw from exhaust. In case there is no oil throw from exhaust, open the expressor sump and check

- Condition of chain whether broken of intact.10


- Condition of J-pipe.- Stud coupling orifice for choking.- Expressor strainer.- Needle valve `O` ring- Needle valve assembly gasket.- Expressor lube oil pump.- Expressor crank shaft and connecting rod bearing.- Crank shaft pin size.

15 wheel skidding

Record brake application and release time for each brake cylinder. Check the brake cylinder pressure on both control stands. It should be 2.5 Kg/Cm2

Record piston travel of each cylinder. Check alignment of piston rod. Check whether application of brakes from SA-9 is gradual or sudden from the both

control stands. Whether the brakes or synchronized or not. Record condition of wheel – length and depth of skidding. Check the no. of deficient brake blocks. Check the hardness of brake blocks.

1 Check piston travel 67mm to 100mm2 Brake cylinder pressure 2.5 Kg/Cm2

3 Gap between brake block and wheel tread (shoe in released condition)

10mm

4 Brake release time 20-25 Seconds.5 Remove brake pressure gauge pipe and check

for chockingClean/chocked

6 Condition of pull rod Should not be bent.7 Tie rod Should not be bent8 Jamming of brake cylinder in case jammed Overhaul and do not

grease9 Check strainer of B/Cyl Chocked/cleaned10 Quality of brake blocks Hardness of brake block

should be 180-220 BHN11 6mm choke in C2 relay valve Fitted/Not fitted12 Proportionate brakes Working/Not working

16 MR pressure not building up

Check whether LP cylinder is throwing air from inlet. If yes, the fallowing may be the reasons;-

- Length of LP unloader assembly is more.- Excessive copper rings under the inlet valves.- Valve plate of inlet valve stuck up.- Foreign material stuck up between plate and valve seat of inlet valve.

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- LP discharge nut loose or worked out, broken stud broken valve plates or permanently set valve spring

- Improper fitting of LP plunger. If LP cylinder is taking air inside but MR pressure not building up, then following may

be the reasons- Leakage in LP head, HP head or inter cooler pipe.- Inter cooler safety valve leaking due to improper setting.- Inter cooler tube burst.- Inter cooler safety valve blowing.- Leakage in pipe lines after HP head.

If LP cylinder neither taking nor throwing air from inlet, then LP piston is damaged17 Inter cooler safety valve blowing If the inter cooler safety valve is blowing the following may be the causes:-

- Excessive length of HP plunger.- Improper fitment of HP unloader plunger.- Excessive copper rings under HP inlet valve.- Valve plate of HP inlet valve sticking/broken/leaky valve.- Broken or missing copper ring in the HP inlet valve.- Loose HP inlet valve nut or broken stud.- Improper setting or sticking of safety valve.- Burrs on valve face.- Loose HP inlet valve guide.If the inter cooler safety valve is blowing after 5 Kg/Cm2 MR pressure, then the following may the defects:-- HP discharge valve nut loose or worked out.- HP discharge valve copper valve ring broken or missing.- HP discharge valve seat/stud broken.- Leaky valve/plate broken/defective HP discharge valve spring.- Burrs on the valve face which seats on HP head discharge.If the inter cooler safety valve is blowing during unloading, then the following may be the defects:-- Total length of LP unloader assembly is less.- Uneven length of LP plunger pin.- Sticking LP plunger in sleeve.- LP inlet valve spring broken/split pin worked out.- LP unloader valve jam/broken packing ring.If the inter cooler safety valve is blowing slightly on loading up to 4th notch but stops after 5th notch, then there will be slight leakage in HP inlet or discharge valve.

18 MR pressure dropping after unloadinga. MR pressure dropping after unloading – setting of AC governor defective or LP

plunger sticking in valve & throwing air out.b. MR pressure dropping after unloading and AC governor throwing air from

orifice and loading unloading not taking place – cut out cock filter choked or defective AC governor or leakage in ABD valve to AC governor pipe line

c. Unloading not taking place properly. LP unloading mal-functioning and AC governor throwing air from orifice – Cut out cock filter chocked or leakage/open connection of ABD valve to AC governor pipe.

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19 MR pressure increasing more than 10 Kg/Cm2 and MR safety valve blowing

- Expressor running continuously on loading – AC governor cut out cock closed or cut out cock filter badly chocked or chocked/open connection of cross pipe with filter/AC governor or defective AC governor

- Loading unloading working up to 5th notch, but after that MR pressure increasing during unloading and MR safety valve blowing – Total length of LP and HP unloader is less.

20 Inter cooler pipe/LP head running hot- Length of HP unloader is more.- Broken or leaky HP inlet valve/copper washer.- Defective intercooler safety valve.- Safety valve not provided.

21 HP head/HP pipe running hota. Discharge valve seat stud broken/nut worked out.b. Discharge valve plate broken.c. Broken/missing discharge valve copper washer.d. Discharge valve guide loose.

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Trouble Shooting

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