1.> BATTERY TESTING
Second week Aug 9-12,2011
Safety- students must wear overalls and steel cap work boots at all the times and need gloves and wear eye protection if opening the battery.
Second week Aug 9-12,2011
Safety- students must wear overalls and steel cap work boots at all the times and need gloves and wear eye protection if opening the battery.
Battery testing was the day we started our first practical on the car,Firstly inspected the battery specification,make of battery,battery no.,battery CCA,type of battery etc.Then we did a battery visual check by checking the terminal of the battery are clean and tight,clamp bolts tight,no electrolyte leakage on case,no corrosion under mounting clamp.
Then remove the battery cap one by one and check all electrolyte level.After this measure the OCV ,measure the terminal voltage across the battery,use a 20V voltmeter,the measured voltage was 10V which means battery dead,now shifted to another car with the voltage of 12.88V which means it is full charged battery.
If the battery is too discharged to load test,we need to charge and test.
Then we recorded hydrometer test result and color of the fluid,specific gravity of battery is measured low as the hydrometer test was not to the specified result.The allowable specific gravity variation is 25-50.After this we did high rate discharge test in which we apply half amps of CCA which is measured as 155amps in my case and the voltage hold above while load is 12.4 and we load for not more then 15 sec .After this we started load tester.In the load tester we connected positive lead to the positive terminal and the negative to negative terminal of battery.Then turned the knob to apply specified load,we waited for specified time and took voltage held and load current reading.After this we did drain and parasitic test,here we here we hooked up the jumper leads to the battery and pulled out the battery,the measured amps 0.01 was ok according to specified as anything less then 0.5A is not ok.
The battery is in good condition so we can still recharge it.We use hot water toothbrush and baking soda to clean the corrosion of the battery.During charging the battery we connected positive to positive and negative to negative terminal and we can charge from 3 hours to overnight (all depends).If the amps draw is too high then we can take out the fuse and check amps going through the fuse.
DIGITAL BATTERY TESTER: For digital meter reading w have to see for SAE flash across the display then we have to change the CCA settings and press 0 button and put the meter around the given components,then the tester will display 1 display out of 4 reading(pass)(fail)(ch)(sf.ch).our display was (pass) therefore battery is in good condition.
2.> LOGIC PROBE CONSTRUCTION
Parts needed to make the logic probe :
1 Brass rod 150mm long
2 Red led
3 Green led
4 Black wire 2m long
5 Red wire 2m long
6 Two resistor 1k ohm
7 Red alligator clip
8 Black Alligator clip
9 100mm plastic tube 7mm id
Shrink tube
Black 2.4mm diameter,About300mm long
Red 6.4mm diameter,About175mm long
Black 12.7mm diameter,About 125mm long
We soldered wire with resistor and led to the brass rod altogether and completed it with improving the appearance using shrink and plastic tube then slide over the wires onto the other end.we used tester for maximum 24V.By connecting the probe to the battery we see that both red and green with light.This test the connection and this shows that the connector is properly connected.
The green led goes off when we touch the probe to the battery positive as the green led is connected to the positive wire and it needs positive and negative to glow up and the red led get brighter as there are two resistor in whole component now by whenever probe is connected to the positive side of the battery.
3.> THE CHARGING SYSTEM > (ALTERNATOR TESTING)
12/08/2011
Safety: Students must wear overalls and steel cap work boots at all times.Resources we required:
The charging system consist of:
But as we, were forced into the alternator working, as we started with the alternator.It consist of rotor, stator, rectifier, regulator.
Firstly started rotor winding to ground test, we took a meter set the meter set meter on 2K and placed the red lead on the slip ring and black on the center of rotor shaft and meter reading comes infinity, so it came as same as specified (infinity) so the test 1 was pass on the alternator.
Then we started with rotor winding internal resistance, test in this we set the ohm meter on 200ohm and place on end of each lend on the slip rings . Measure the reading it came 3.2 ohm and the actual reading is also taken by touching both the lead ,it is 3.16ohm and the less internal meter resistance is by subtraction acctualy and obtain reading comes to be 0.04 ,and spec. is 2-6ohm ,so we pass the second test on alternator as value was in the given specification.
After the internal, I started with winding resistance in this again set the meter on 200ohms, then tested the internal meter reading by touching the two leads together, which comes to be 0.04ohm ,then I selected a common point , put a black probe on the one with most wires ) and connect the red lead to the other terminal one after the other from the A to D. Record the resistance (should be approx. from 0.0 - 2ohms). The meter reading measured was A=0.4, B=common point, C=0.5 and D=0.4. The test was pass. after this we do vice versa put the meter on 2K now place the red lead on common point and black lead on the meter of the body of alternator.The actual reading measured was infinity as spec. ,the test was again pass like previous test.
From here we were ask to test diodes. In this for positive diode testing with common lead on B , and touch positive lead on each 'P' terminal. The spec. reading for this should be 0.5vd to 0.7vd . we tested the 4 diode in which for one the reading comes to be .25vd which is almost fail as it will stop working soon . So rectifier should be replaced and the result for the positive diode testing with positive lead on B the spec. is infinity and we get all 4 diodes fail and shows the replacement for rectifier , as soon as possible to make charging system work .
The same we do for the negative diodes but here we keep common and postive lead on E . The result for the rectifier was mostly fail , so the rectifier is faulty ,should be immegidetly change.
>Now, we were ask to test the voltage regulator in this we have to locate a wiring diagram for the regulator to identify correct or use point voltage for the specification but due to a short circuit lights on , we couldn't get the reading and test was fail.
>Then the size of brushes was measured which were more then spec minimum, that means it was pass.
>From all the test we concluded this that few component of alternator is in good condition , and can work well but other parts are too low and damage so, the alternator should be changed as soon as possible to maintain the charging system in the vehicle or should be repair.
Then remove the battery cap one by one and check all electrolyte level.After this measure the OCV ,measure the terminal voltage across the battery,use a 20V voltmeter,the measured voltage was 10V which means battery dead,now shifted to another car with the voltage of 12.88V which means it is full charged battery.
If the battery is too discharged to load test,we need to charge and test.
Then we recorded hydrometer test result and color of the fluid,specific gravity of battery is measured low as the hydrometer test was not to the specified result.The allowable specific gravity variation is 25-50.After this we did high rate discharge test in which we apply half amps of CCA which is measured as 155amps in my case and the voltage hold above while load is 12.4 and we load for not more then 15 sec .After this we started load tester.In the load tester we connected positive lead to the positive terminal and the negative to negative terminal of battery.Then turned the knob to apply specified load,we waited for specified time and took voltage held and load current reading.After this we did drain and parasitic test,here we here we hooked up the jumper leads to the battery and pulled out the battery,the measured amps 0.01 was ok according to specified as anything less then 0.5A is not ok.
The battery is in good condition so we can still recharge it.We use hot water toothbrush and baking soda to clean the corrosion of the battery.During charging the battery we connected positive to positive and negative to negative terminal and we can charge from 3 hours to overnight (all depends).If the amps draw is too high then we can take out the fuse and check amps going through the fuse.
DIGITAL BATTERY TESTER: For digital meter reading w have to see for SAE flash across the display then we have to change the CCA settings and press 0 button and put the meter around the given components,then the tester will display 1 display out of 4 reading(pass)(fail)(ch)(sf.ch).our display was (pass) therefore battery is in good condition.
2.> LOGIC PROBE CONSTRUCTION
Parts needed to make the logic probe :
1 Brass rod 150mm long
2 Red led
3 Green led
4 Black wire 2m long
5 Red wire 2m long
6 Two resistor 1k ohm
7 Red alligator clip
8 Black Alligator clip
9 100mm plastic tube 7mm id
Shrink tube
Black 2.4mm diameter,About300mm long
Red 6.4mm diameter,About175mm long
Black 12.7mm diameter,About 125mm long
We soldered wire with resistor and led to the brass rod altogether and completed it with improving the appearance using shrink and plastic tube then slide over the wires onto the other end.we used tester for maximum 24V.By connecting the probe to the battery we see that both red and green with light.This test the connection and this shows that the connector is properly connected.
The green led goes off when we touch the probe to the battery positive as the green led is connected to the positive wire and it needs positive and negative to glow up and the red led get brighter as there are two resistor in whole component now by whenever probe is connected to the positive side of the battery.
3.> THE CHARGING SYSTEM > (ALTERNATOR TESTING)
12/08/2011
Safety: Students must wear overalls and steel cap work boots at all times.Resources we required:
- Digital multimeter.
- Alternator.
- Regulator tester.
- Rear housing puller and installer.
- Vernier callipers.
- A selection of hand tools.
The charging system consist of:
- Battery
- Alternator
- Drive Belt
- Wiring
- Ignition key (switch)
- Warning light
- Engine
But as we, were forced into the alternator working, as we started with the alternator.It consist of rotor, stator, rectifier, regulator.
Firstly started rotor winding to ground test, we took a meter set the meter set meter on 2K and placed the red lead on the slip ring and black on the center of rotor shaft and meter reading comes infinity, so it came as same as specified (infinity) so the test 1 was pass on the alternator.
Then we started with rotor winding internal resistance, test in this we set the ohm meter on 200ohm and place on end of each lend on the slip rings . Measure the reading it came 3.2 ohm and the actual reading is also taken by touching both the lead ,it is 3.16ohm and the less internal meter resistance is by subtraction acctualy and obtain reading comes to be 0.04 ,and spec. is 2-6ohm ,so we pass the second test on alternator as value was in the given specification.
After the internal, I started with winding resistance in this again set the meter on 200ohms, then tested the internal meter reading by touching the two leads together, which comes to be 0.04ohm ,then I selected a common point , put a black probe on the one with most wires ) and connect the red lead to the other terminal one after the other from the A to D. Record the resistance (should be approx. from 0.0 - 2ohms). The meter reading measured was A=0.4, B=common point, C=0.5 and D=0.4. The test was pass. after this we do vice versa put the meter on 2K now place the red lead on common point and black lead on the meter of the body of alternator.The actual reading measured was infinity as spec. ,the test was again pass like previous test.
From here we were ask to test diodes. In this for positive diode testing with common lead on B , and touch positive lead on each 'P' terminal. The spec. reading for this should be 0.5vd to 0.7vd . we tested the 4 diode in which for one the reading comes to be .25vd which is almost fail as it will stop working soon . So rectifier should be replaced and the result for the positive diode testing with positive lead on B the spec. is infinity and we get all 4 diodes fail and shows the replacement for rectifier , as soon as possible to make charging system work .
The same we do for the negative diodes but here we keep common and postive lead on E . The result for the rectifier was mostly fail , so the rectifier is faulty ,should be immegidetly change.
>Now, we were ask to test the voltage regulator in this we have to locate a wiring diagram for the regulator to identify correct or use point voltage for the specification but due to a short circuit lights on , we couldn't get the reading and test was fail.
>Then the size of brushes was measured which were more then spec minimum, that means it was pass.
>From all the test we concluded this that few component of alternator is in good condition , and can work well but other parts are too low and damage so, the alternator should be changed as soon as possible to maintain the charging system in the vehicle or should be repair.
DOING THE REST ....SOON WILL BE POSTED
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