ROTOR |
| |
MEASURE RESISTANCE IN | THE | |
| FIELD COIL OF THE ROTOR WITH | |
| A CIRCUIT TESTER |
|
| Resistance | Stlip |
| value |
|
El 10.7J-z
Note 1: Measure the coil resistance between the two slip rings.
Note 2: Sometimes the measured values do not match the values shown in the table above because of errors by the circuit tester, unevenness of the coil windings, or peripheral temperatuer.
8-5-2 CLEANING OF SLIP RING
F&T
When the surface of the slip ring is smooth it is normal. When it is dirty or abraded, it should be repaired.
When the slip ring is dirty efficiency of the generator may become lower and sufficient voltage and output can not be obtained. In this case, sand around the slip ring with fine sandpaper.
Slip Ring
Note: When sandpaper is used, be careful not to damage the coils of the rotor.
Fig.
If the surface of the brush contacting the slip ring is smooth, it is normal. If not, make it smooth with sandpaper.
Unless the surface is smooth, an arc may be generated between the brush and the slip ring, which may damage the brush and the slip ring.
The brush length should be, as shown in Fig. 8- 6, within the range from 1.5 mm to 5 mm. If it is below 5 mm, it should be exchanged with a proper one. When contact voltage between the brush and the slip ring becomes lower, efficiency of the generator also becomes lower and sufficient voltage and output can not be obtained.
Fig.
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