DIESEL LOCO -Electrical Rotating Machines

January 5, 2021, 8:01 PM

Electrical Rotating Machines

There are 11 rotating machines provided on loco.

1. Traction Alternator
2. Auxiliary Generator
3. Exciter Generator
4. Techo Generator
5. Axle Generator
6. Traction Motor
7. Fuel Pump Motor
8. Crank Case Exhauster Motor
9. Dynamic Braking Blower Motor
10. Eddy Current Clutch Coil
11. Cyclonic Motor
1. Traction Alternator

It is a 3φ AC Generator.
It is located in Alternator room.
It converts mechanical energy into electrical energy.
Alternator field (rotor) is connected to diesel engine crank shaft. Its field is excited by exciter generator through two slip rings and carbon brushes. Current produced by alternator armature (stator) is given to rectifier block; it converts AC into DC. Through power circuit DC supply given to Traction motor.
It is a self cooled through fly wheel.
Maximum rpm of rotor is 400 -1050 rpm, and no load voltage is 1130 volt DC.

2. Auxiliary Generator

1. It is a self excited DC shunt Generator.
2. It is located at engine left side in Alternator room.
3. It is driven by the bull gear of main generator
4. Auxiliary generator works as followsa) Charges the battery

Excites the filed of exciter generator
Gives supply to FPM, CCM and ECC
Gives supply to control and lighting circuits
Auxiliary generator works as a motor at the time of engine cranking.

5. When auxiliary generator is not working, AGFL glows on control panel.
6. Auxiliary Generator junction box having 4 wires AGA1, AGA2, AGF1 and AGF2.

7. AGFB circuit breaker is provided to safe guard Auxiliary generator field winding.
8.Its output voltage 72±1 volt which is controlled by VRP (Voltage Regulating panel)

3. Exciter Generator

1. It is a separately excited DC Generator.
2. It is located in Alternator room.
3. It is driven by the bull gear of Traction Alternator.
4. The field of the exciter generator is excited by either Auxiliary generator or battery. It excites the field of Traction Alternator. If the exciter generator is defective, Traction alternator does not generate the current.
5. It works as motor at the time of engine cranking.

4. Techo Generator

1. It is permanent magnet 3φ delta connected AC generator
2. It is located at engine right side power take off end.
3. It is driven by the right side cam shaft gear.
Its function is –

In EH governor loco gives current to speed coils to control engine speed and SAR coil.
In WW governor loco, gives current to function generator card (excitation system).

There are 3 terminal connections 31L, 31M and 31N in the junction box. If any connection is loose, engine will shut down without any indication in EH governor loco.

5. Axle Generator

1. It is a permanent magnet single phase AC Generator.
2. It is fitted on L2 axle box.
3. It gives current to transition panel.
4. It is driven by the Spline shaft which is fitted on the L2 axle. Its rotor rotates in proportionate to the speed of the loco. The output of the axle generator is connected to TET by the two terminals of wire No. 45B, 45C. TET is connected to Transition Panel by wire No. 46, 46A. If wire connections are loose on axle generator automatic transaction will not come.
5. Ensure the foundation bolt and safety chain of axle generator is intact.

6. Traction Motor (TM)

1. It is DC series motor.
2. It is fitted on each axle in under truck of loco with the help of suspension bearing and nose pad. (06 TM are provided on loco)
3. It converts electrical energy of traction alternator into mechanical energy which rotates the wheels of Loco.
4. Its pinion gear has 18 teeth matched with axle gear having 74 teeth.
5. At the time of traction the armature and field of motor are connected in series with the help of BKT.
6. During dynamic braking all TM field and armature are separated with the help of BKT, fields are connected in series with each other across the main generator and armatures are connected in groups (1-4, 2-5, 3-6) with the grids. It works as separately excited generator.
7. For cooling the TM there are 2 blowers. FTTM blower cools TM No.1, 2, 3 and RTTM blower cools TM No.4, 5, 6.
8. Non explosive power takes place when earth fault in traction motor.
9. One MCO is provided on front panel to isolate the defective traction motor.
10. Load meter is provided on both control stands to show the TM current.

7. Fuel Pump Motor

1. It is a DC compound motor.
2. It is Located in the compressor room engine right side.
3. It gives drive to the fuel oil pump and EH governors pump.
4. Initially it gets supply from battery and after engine starting from Auxiliary Generator .
5. FPB breaker is provided on control panel to safe the fuel pump motor from over current
6. There are two terminals in the junction box of FPM, wire No.71 and 4. In case of fuel pump motor failure, the fuel oil pressure drops to zero and engine will shut down.

8. Crankcase Exhauster Motor

1. It is a DC compound motor
2. It is located on engine left side at power take off end.
3. It is provided to exhaust the fumes from the crank case sump and creates a partial vacuum.

4. Initially it gets supply from battery and after engine starting from auxiliary generator.
5. CEB circuit breaker is provided on front panel to protect CCM from over current.
6. There are two wire terminals in the junction box, wire no 70A and 4.
7. To ensure the working of CCM the indication lamp is provided on both the control stands, it will glow when CCM not working.
8. If CCM is not working, first clear the section and inform to PCOR and fail the loco.

9. Dynamic Braking Blower Motor (BKBL)

1. It is a DC series motor.
2. It is located in Nose compartment.
3. Two blowers are fitted on each side of its armature shaft, during dynamic braking it starts and cools the braking grids. At the time of dynamic braking, electric supply generated by traction motors is used to rotate BKBL.

If BKBL is not working, do not use dynamic brakes.

10. Eddy Current Clutch Coil (ECC) Assembly

1. It is located in the radiator room.
2. It is controls the speed of radiator fan.
3. In this assembly there are two drums, inner drum and outer drum. Outer drum is connected to extension shaft No.2 and rotate with main crank shaft and inner drum is connected with the radiator fan through the right angle gear box. ECC coil is fitted on Inner Drum and works on the principle of eddy current. There are two wires connected in its junction box wire No.72 and 4. Two slip rings with four carbon brushes are fitted on inner drum. When supply is given to ECC, inner drum also starts to rotate with outer drum thus radiator fan start rotating and cools the water.

11. Cyclonic Motor

1. It is provided under truck near wheel no.6 both side of Loco.
2. A blower is fitted on Cyclonic Motor shaft which sucks the dust from cyclonic filter dirt collector and through the same in atmosphere.
3. One circuit breaker DEB is provided in loco pilot cab.
4. One indication lamp is provided on indication panel of front panel.
5. It starts working from 5th notch when DEB ON.
6. When cyclonic motor fails inform to PCOR.

Note – In 11 and 13 series Loco two additional Cyclonic Motors are provided on both side of alternator.

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