Field Flashing of Portable Generators
This tip comes from the Briggs & Stratton Customer Education
Department. As an alternative to flashing a rotor winding with a
battery applied to the brushes, an electric drill may be used. Follow
these steps to flash the generator:
- Plug the electric drill into the generator receptacle. (Cordless drills do not work)
- If the drill is reversible, move the direction switch to the forward position.
- Start the generator
depressing the trigger on the drill, spin the drill chuck in reverse
direction. This will excite the field and the generator will now
produce electricity. If spinning the chuck one direction does not work,
try spinning the chuck in the other direction as you may have the
reverse switch positioned backwards.
Use caution not to get your hand or other materials caught in the
chuck. As soon as the field is excited, the generator will produce
power and the drill will turn on.
The reason this works is because the electric motor in the drill will
act as a small generator when spun backwards. The magnets in the
drill's motor induce a voltage into the motor windings, which is fed
back through the trigger, cord and into the generators receptacle. From
there it goes into the power winding of the stator. The voltage going
through the power winding creates a magnetic field, which is
intensified due to the iron core of the stator laminations. The rotor
intersects this magnetic field as it is spun past the power winding,
thus inducing a voltage in the rotor winding. Once current flow is
present in the rotor winding the rotor has been flashed.
If flashing the field does not make the generator work, you may have
additional problems, besides a lack of magnetism in the rotor. Further
testing will be needed. Hopefully, this will give a simple way to field
flash your generator if needed - Bruce Perrault