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techtalk:ih:elec02a [2018/12/16 23:36] hippysmack |
techtalk:ih:elec02a [2023/12/30 01:32] (current) hippysmack |
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====== IH: Electrical System - Sub-02A ====== | ====== IH: Electrical System - Sub-02A ====== | ||
====== Bench Testing a Generator ====== | ====== Bench Testing a Generator ====== | ||
- | Article by sifty of the XLFORUM ((http://xlforum.net/forums/showthread.php?t=1592463&page=42)) \\ | + | Article by sifty of the XLFORUM ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/146604-first-harley-1975-xl1000-caf%C3%A9-project/page42?t=1592463&page=42)) \\ |
Some simple diagnostic tests can be done with a multimeter. \\ | Some simple diagnostic tests can be done with a multimeter. \\ | ||
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{{ :techtalk:ih:elec:generator_drawing_1_by_sifty.jpg?direct&500|}} | {{ :techtalk:ih:elec:generator_drawing_1_by_sifty.jpg?direct&500|}} | ||
- | * Generators are fairly simple, they consist of; ((photo by sifty of the XLFORUM ((http://xlforum.net/forums/showthread.php?t=1592463&page=42)) | + | * Generators are fairly simple, they consist of; ((photo by sifty of the XLFORUM ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/146604-first-harley-1975-xl1000-caf%C3%A9-project/page42?t=1592463&page=42)) |
* Field windings are designated "F" (attached to the case). | * Field windings are designated "F" (attached to the case). | ||
* Armature windings are designated as "A" (wound around the rotating shaft). | * Armature windings are designated as "A" (wound around the rotating shaft). | ||
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\\ | \\ | ||
\\ | \\ | ||
- | |||
====== Brush assembly ====== | ====== Brush assembly ====== | ||
{{ :techtalk:ih:elec:generator_pic_by_sifty.jpg?direct&400|}} | {{ :techtalk:ih:elec:generator_pic_by_sifty.jpg?direct&400|}} | ||
- | The brush plate is easily removable, and inspection/ cleanup should be straight forward. ((photo by sifty of the XLFORUM http://xlforum.net/forums/showthread.php?t=1592463&page=42)) \\ | + | The brush plate is easily removable, and inspection/ cleanup should be straight forward. ((photo by sifty of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/146604-first-harley-1975-xl1000-caf%C3%A9-project/page42?t=1592463&page=42)) \\ |
Care must be taken when installing the brush plate. \\ | Care must be taken when installing the brush plate. \\ | ||
Make sure that the brush- armature connecting wire is not pinched (can short circuit to the frame). \\ | Make sure that the brush- armature connecting wire is not pinched (can short circuit to the frame). \\ | ||
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Ensure the connecting wires are tightened in a position to allow full movement. \\ | Ensure the connecting wires are tightened in a position to allow full movement. \\ | ||
And make sure the bare end of the armature brush wire does not contact the case or end cap on assembly. | And make sure the bare end of the armature brush wire does not contact the case or end cap on assembly. | ||
+ | |||
====== Terminal insulation ====== | ====== Terminal insulation ====== | ||
- | |||
The terminals must be insulated between where they go through the case and connect to the windings. \\ | The terminals must be insulated between where they go through the case and connect to the windings. \\ | ||
There will be some sort of fiber or plastic bushing around them at this point. \\ | There will be some sort of fiber or plastic bushing around them at this point. \\ | ||
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====== Armature ====== | ====== Armature ====== | ||
- | |||
Testing on the Ohms scale between each commutator segment and the exposed iron core will indicate any short circuits to ground. \\ | Testing on the Ohms scale between each commutator segment and the exposed iron core will indicate any short circuits to ground. \\ | ||
Each segment should show very high resistance to ground (ideally in the Mega-ohms range). \\ | Each segment should show very high resistance to ground (ideally in the Mega-ohms range). \\ | ||
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With the generator cleaned, assembled and on the bench, some simple test with the multimeter in the Ohms scale can tell you a lot about its electrical health. \\ | With the generator cleaned, assembled and on the bench, some simple test with the multimeter in the Ohms scale can tell you a lot about its electrical health. \\ | ||
The figures noted here were the results from 2 generators (different models). \\ | The figures noted here were the results from 2 generators (different models). \\ | ||
- | They should be reasonably typical the standard 12V Harley generator. ((photo by sifty of the XLFORUM http://xlforum.net/forums/showthread.php?t=1592463&page=42)) | + | They should be reasonably typical the standard 12V Harley generator. ((photo by sifty of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/146604-first-harley-1975-xl1000-caf%C3%A9-project/page42?t=1592463&page=42)) |
\\ | \\ | ||
{{ :techtalk:ih:elec:generator_drawing_2_by_sifty.jpg?direct&400|}} | {{ :techtalk:ih:elec:generator_drawing_2_by_sifty.jpg?direct&400|}} | ||
- | Field winding resistance: \\ | + | **Field winding resistance**: \\ |
Placing the leads across the A and F terminals will give you the effective resistance of the field windings (2 windings in series). \\ | Placing the leads across the A and F terminals will give you the effective resistance of the field windings (2 windings in series). \\ | ||
The armature circuit is not included as in a healthy generator there is no return path via ground to the meter. \\ | The armature circuit is not included as in a healthy generator there is no return path via ground to the meter. \\ | ||
This should be around the 5.8 ohm mark, a higher figure indicates a possible open circuit, and a lower figure may mean a winding is shorting out somewhere. | This should be around the 5.8 ohm mark, a higher figure indicates a possible open circuit, and a lower figure may mean a winding is shorting out somewhere. | ||
- | Armature resistance: \\ | + | **Armature resistance**: \\ |
Placing one lead on a good, clean ground point on the case (shiny metal) and the other on the A terminal, will follow the path through the armature to ground. \\ | Placing one lead on a good, clean ground point on the case (shiny metal) and the other on the A terminal, will follow the path through the armature to ground. \\ | ||
This should be very low, typically less than 0.6 ohms but can vary as it depends on the brush/commutator condition. | This should be very low, typically less than 0.6 ohms but can vary as it depends on the brush/commutator condition. | ||
- | Total resistance: \\ | + | **Total resistance**: \\ |
Placing the leads on a good ground point and the F terminal effectively measures the field plus armature circuits in series (from the F terminal, through the field windings, then through the armature to ground). \\ | Placing the leads on a good ground point and the F terminal effectively measures the field plus armature circuits in series (from the F terminal, through the field windings, then through the armature to ground). \\ | ||
As a quick check, this result should be very close to the values of the previous tests added together. | As a quick check, this result should be very close to the values of the previous tests added together. | ||
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{{ :techtalk:ih:elec:generator_drawing_3_by_sifty.jpg?direct&400|}} | {{ :techtalk:ih:elec:generator_drawing_3_by_sifty.jpg?direct&400|}} | ||
- | With the brushes out there are a couple of further tests available: ((photo by sifty of the XLFORUM http://xlforum.net/forums/showthread.php?t=1592463&page=42)) \\ | + | With the brushes out there are a couple of further tests available: ((photo by sifty of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/146604-first-harley-1975-xl1000-caf%C3%A9-project/page42?t=1592463&page=42)) \\ |
- | Winding insulation: \\ | + | **Winding insulation**: \\ |
Placing one lead on a clean ground point of the casing, and the other on either terminal (do both) should give a very high reading (ideally in the Mega-ohms range). \\ | Placing one lead on a clean ground point of the casing, and the other on either terminal (do both) should give a very high reading (ideally in the Mega-ohms range). \\ | ||
This indicates the windings are not shorting to ground anywhere. | This indicates the windings are not shorting to ground anywhere. | ||
- | Winding current: \\ | + | **Winding current**: \\ |
Connecting the battery through the multimeter in the Amps scale should result in a DC current of around 2 amps. \\ | Connecting the battery through the multimeter in the Amps scale should result in a DC current of around 2 amps. \\ | ||
Ohms law states V = IR, so with 12V and a resistance of around 6 ohms I = V/R which gives the 2 amps (will vary in practice as your winding resistance and battery voltage will differ). \\ | Ohms law states V = IR, so with 12V and a resistance of around 6 ohms I = V/R which gives the 2 amps (will vary in practice as your winding resistance and battery voltage will differ). \\ | ||
- | Motor test: \\ | + | **Motor test**: \\ |
This is probably the best indication, as a generator that will motor with voltage applied indicates all is well with the commutator / brush assembly. \\ | This is probably the best indication, as a generator that will motor with voltage applied indicates all is well with the commutator / brush assembly. \\ | ||
Jumper leads from a good battery were used and a short piece of wire (applied +12V to the A terminal, and -12V to the case and F terminal simultaneously). \\ | Jumper leads from a good battery were used and a short piece of wire (applied +12V to the A terminal, and -12V to the case and F terminal simultaneously). \\ |