Aug.16th to 19th 2011 (3rd week)
STARTER
Resources: Starter motor test bench, 6-12 volt power supply , digital voltmeter, armature growler, 45 volt test light, suitable tools and equipment to enable starter motors to be dismantled and repaired, pre-engaged starter motor, manufactures specification if possible, and the work book.
Before performing test on stater motor, we should mark the stater motor for easy assemble after test. Then started with the visual inspection test check for signs of
The test report for visual inspection is all good.
Before the starter test, just note down the , Make and model number of starter motor . Then tested the Armature ground test ,in this we use multi-meter in the ohms range and check for the ground short circuit btw each of the commutator segments and armature core or shaft, using the multi-meter at 200ohm we performed the test to ensure that the ground test was to infinity. we then started with continuity circuit test with the ohmmeter in the same range , we checked the continuity btw one of the commutator segments while moving the second probe around on each of the other commutator segments. we resulted with 0.2 ohm which was inside the manufacturer's specification.
- Overheating.
- Burning.
- Physical damage of insulation and coil windings.
The test report for visual inspection is all good.
Before the starter test, just note down the , Make and model number of starter motor . Then tested the Armature ground test ,in this we use multi-meter in the ohms range and check for the ground short circuit btw each of the commutator segments and armature core or shaft, using the multi-meter at 200ohm we performed the test to ensure that the ground test was to infinity. we then started with continuity circuit test with the ohmmeter in the same range , we checked the continuity btw one of the commutator segments while moving the second probe around on each of the other commutator segments. we resulted with 0.2 ohm which was inside the manufacturer's specification.
to check with the commutator , we measured the commutator diameter and check the mica undrcut depth as necesssry . The result for minimum diameter came to be 30mm (should be frm 26.8mm to 31 mm) and mica undercut ws 0.9mm (should be 0.7 to 1.0 mm) So it also passes the manufacturer's specification ,so the test was pass. After this we ran Amature shaft for a run out and we did this by placing the armature btw the 'v' blocks and turn the armature 360 degree while reading the dial test indicator core as indicated by the arrow. our result was 0.1mm which ws pass and serviceable as manufacturer's specification are 0mm to 0.2mm.
We also tested the Armature with alternative method by using 48 volt test light machine to test the continuity test, keep one probes on one segment and move the other probe around each of other segments to check where light glow, the continuity test light on over each segment was successfully passed as light over each segment glow. after this ran a test for ground test light off, here we placed one prob on any commutator segment and the other on either the armature core or shaft ,here also the the test was pass as light ws off over each segment.
After this we tested for internal short circuits using growler, we placed the armature on the 'v' of the growler and turn the switch on to growler position, then holding a hacksaw blade or metal strip along the armature and rotate the armature , where as the blade will vibrate over shorted winding indicating a shorted armature. But we succeeded as there were no vibrations on the blade.
After that we started with the field coil and pole shoes, before starting we need to do visual inspection , I checked the over heating, burning , physical damage of insulation and coil windings and poling , the test report was all pass for all these above as there was no such signs found and so they are serviceable.
Then tested the field coils for the continuity in the field winding place the probes on each end of the field winding, and it depends on the design of stater motor circuit , field winding motor circuit , field winding maybe grounded or insulated from the field housing. We ran a test to see if a field coil had any resistance when grounded and we got 0 ohms and the spec is 0 ohms to 2 ohms. And also ran a test for the field coils for grounding , here just place the positive probe on the field wire or brush , then the common probe on the body of the starter. ( note , the field winding should not be attached to the body of the starter motor), and our result here was infinity so as the specified so this test was also passed.
Then came to the brushes , here we were ask to measure the length of the brushes and inspect for cracks and other damages.The manufacturing specification for brushes minimum lenght is 5mm , n the result was 12mm , 14mm, 13mm, 12mm all the brushes were in good condition and passed the test.
After the brushes came to test the brush holder assembly to check the short circuit between insulated brushes and holder , first set the ohms meter on the lowest resistance. place one of the probe on the brush and other on the metal retaining plate and got 0.01ohms of resistance this shows that the brush holder is grounded holder ( spec. manufactured btween 0 - 0.2ohms) so the test was pass.
Then we performed for the solenoid test where we connected the solenoid to 9v power supply between S (ignition/starter switch) and M terminals (starter motor supply) . THIS TEST IS DONE UNDER REDUCE VOLTAGE AND FOR MAX OF 5 SEC TO PREVENT HEAT DAMAGAGE TO WINDINGS.
our result for pull in winding measured came to be 10amps current draw which resulted pass as manufactured specification is 8- 12 amps and physical action also passed as the plunger was puled in while the test and so itz pass and can be serviceable .
And in the hold in winding we connect the 9v power supply btw S and solenoid body. The test was again passed as the current there was 6amps , so ws btw 5-8amps and the physical action was resulted to be pass as here as the plunger is release when power is disconnected.
AFTER then checked the pinion gear , bushes ,clutch, did a visual inspection here so the pinion gear and clutch is in good condition and bushes have no damage and all 3 can be serviceable.
And then assemble the stator again and after assembling we have a final check on it , vchecked the stator on the cryton electrical test bench and all was good as well it was working and the test result was same as before the test 13.8V and 44amps
2.> Relays
Reources: 12 volt power supply, Digital multimeter, circuit board, 12 wires of at least 3 different colours.
A relay uses a low amperage circuit to switch on higher amperage circuit. They are very common on vehicles and although there are many types,they are similar in how they work.
And the control circuit will have a coil of wire that creates magnetism when the circuit is powered and earthed. The switching circuit will have a set of point contacts that are switched by having the magnetism pull the points contact with another set of points . there may not be a circit that is complete when the relay is off or un - powered.
NOTE: Low amps in the control circuit creates magnetism to move the switch points to other position and the switch contacts can now turn on a higher amperage device.
The control circuit usually gets power from the battery. And it will have a switching device in it that turn the circuit on and off .Switch can be positive side or the earth side. It will be switched by a switch , a sensor with a switch inside it, or an ECU (electronic control unit) that does the switching based on a logic circuit.
The switching circuit usually also gets power from the battery . Its circuit contain a device that needs to be turned on or off. and this circuit will usually end in the device being earthed to provide a complete circuit.
AFTER this calculated the amps and wire up the relay and also measure the available voltage which was :
circuit off / circuit on Control circuit
After this we tested for internal short circuits using growler, we placed the armature on the 'v' of the growler and turn the switch on to growler position, then holding a hacksaw blade or metal strip along the armature and rotate the armature , where as the blade will vibrate over shorted winding indicating a shorted armature. But we succeeded as there were no vibrations on the blade.
After that we started with the field coil and pole shoes, before starting we need to do visual inspection , I checked the over heating, burning , physical damage of insulation and coil windings and poling , the test report was all pass for all these above as there was no such signs found and so they are serviceable.
Then tested the field coils for the continuity in the field winding place the probes on each end of the field winding, and it depends on the design of stater motor circuit , field winding motor circuit , field winding maybe grounded or insulated from the field housing. We ran a test to see if a field coil had any resistance when grounded and we got 0 ohms and the spec is 0 ohms to 2 ohms. And also ran a test for the field coils for grounding , here just place the positive probe on the field wire or brush , then the common probe on the body of the starter. ( note , the field winding should not be attached to the body of the starter motor), and our result here was infinity so as the specified so this test was also passed.
Then came to the brushes , here we were ask to measure the length of the brushes and inspect for cracks and other damages.The manufacturing specification for brushes minimum lenght is 5mm , n the result was 12mm , 14mm, 13mm, 12mm all the brushes were in good condition and passed the test.
After the brushes came to test the brush holder assembly to check the short circuit between insulated brushes and holder , first set the ohms meter on the lowest resistance. place one of the probe on the brush and other on the metal retaining plate and got 0.01ohms of resistance this shows that the brush holder is grounded holder ( spec. manufactured btween 0 - 0.2ohms) so the test was pass.
Then we performed for the solenoid test where we connected the solenoid to 9v power supply between S (ignition/starter switch) and M terminals (starter motor supply) . THIS TEST IS DONE UNDER REDUCE VOLTAGE AND FOR MAX OF 5 SEC TO PREVENT HEAT DAMAGAGE TO WINDINGS.
our result for pull in winding measured came to be 10amps current draw which resulted pass as manufactured specification is 8- 12 amps and physical action also passed as the plunger was puled in while the test and so itz pass and can be serviceable .
And in the hold in winding we connect the 9v power supply btw S and solenoid body. The test was again passed as the current there was 6amps , so ws btw 5-8amps and the physical action was resulted to be pass as here as the plunger is release when power is disconnected.
AFTER then checked the pinion gear , bushes ,clutch, did a visual inspection here so the pinion gear and clutch is in good condition and bushes have no damage and all 3 can be serviceable.
And then assemble the stator again and after assembling we have a final check on it , vchecked the stator on the cryton electrical test bench and all was good as well it was working and the test result was same as before the test 13.8V and 44amps
2.> Relays
Reources: 12 volt power supply, Digital multimeter, circuit board, 12 wires of at least 3 different colours.
A relay uses a low amperage circuit to switch on higher amperage circuit. They are very common on vehicles and although there are many types,they are similar in how they work.
And the control circuit will have a coil of wire that creates magnetism when the circuit is powered and earthed. The switching circuit will have a set of point contacts that are switched by having the magnetism pull the points contact with another set of points . there may not be a circit that is complete when the relay is off or un - powered.
NOTE: Low amps in the control circuit creates magnetism to move the switch points to other position and the switch contacts can now turn on a higher amperage device.
The control circuit usually gets power from the battery. And it will have a switching device in it that turn the circuit on and off .Switch can be positive side or the earth side. It will be switched by a switch , a sensor with a switch inside it, or an ECU (electronic control unit) that does the switching based on a logic circuit.
The switching circuit usually also gets power from the battery . Its circuit contain a device that needs to be turned on or off. and this circuit will usually end in the device being earthed to provide a complete circuit.
Then were asked to measure resistance, then identified control circuit and switching circuit.
- control circuit- 86 and 85
- switched points that carry higher amps-30,87,87A
AFTER this calculated the amps and wire up the relay and also measure the available voltage which was :
circuit off / circuit on Control circuit
- 86- 12V / 12v -current-0.16A
- 85- 12V / 0V Consumer circuit
- 30- 12V / 12V -current-0.38A
- 87A- 12V / 0V
- 87- 0V / 12V
* voltage change the most at 87A,87 AND 85.
When the switch is off,the terminal 86,85,30 there is voltage because as there is no voltage being used and circuit is closed. But when the circuit is on ,the voltage use changes at these terminals 86,85 and 87. So the voltage goes to the relay and the light bulb. Terminal 85 has voltage when switch is off, but no voltage when switch is on because when it is on , the magnetic coil drains the voltage from 85. 86 to energize leaving no voltage in 85. 86 still has voltage because it is connected to power supply. and 87 has volts when the switch is off but has no voltage when it is on because the switch changes the circuit route to 87A .,so 87A now have the voltage , when switch is off 87A has no volts because the switch has the circuit route going to 87.
DOING THE REST ONEZZZ...!!!
ReplyDelete