Short Circuit or Resistance Test - CS-144 Generator

Test the winding for short circuits or excessive resistance by connecting a battery and ammeter in series with the edge of the two slip rings. Note the ammeter reading and refer to "Specifications". An ammeter reading above the specified value indicates shorted windings.

An alternate method is to check the resistance of the field by connecting an ohmmeter to the two slip rings. If the resistance reading is above the specified value, the winding has excessive resistance; if below the specified value, the winding is shorted. The specified resistance value can be determined by dividing the voltage by the current.

Remember that the winding resistance and ammeter readings will vary slightly with winding temperature. If the rotor is not defective, but the generator fails to sup- ply rated output, the problem is in the rectifier bridge, stator, or regulator.

If the rotor fails any of the above checks, replace it.