Bias Torque Adjustment; Clutch Adjustment - GE IBCG51M A Series Instructions Manual

Loosen the locknut which secures the backstop screw (located at the right hand
corner of the unit) to its support.
contact arm is permitted to swing freely.
contact brush so that one-to-two grams of pressure are required at the contact tip.in
order to cause the end of the brush to separate from the inner face of its
brush retainer.
position, i.e., with the arm pointing directly forward.
secures the stationary contact mounting screw to the stationary contact support.
the mounting screw inward until the stationary and moving contact members just begin to
Unwind the mounting screw until the stationary contact stop lines up with the
touch.
moving contact brush retainer.
stationary contact members again just begin to touch.
stationary contact stop screw, and advance this screw until it just touches the moving
contact brush retainer. Unwind the screw one and a half turns to provide contact
Tighten the locknut.
secures the backstop screw to its support.
stationary contact brush such that, when the contacts are made and fully wiped in, ,
there is approximately an equal deflection on each brush.

Bias Torque Adjustment

Connect the current operating and current polarizing coils in series by connecting a
jumper across terminals 5 and 8.
directional unit spiral spring so that the unit picks up at 0.5 ampere with terminals 9
and 10 jumpered.
The core of the directional unit has a small flat portion, the purpose of which is to
minimize the effect of bias torques produced on the rotor.
produced by any one of the operating or polarizing quantities acting alone with the
other two circuits de-energized.
but may be checked by observing that the unit responds as outlined below:
Short out the potential polarizing coil (terminals 9 and lo), leaving the current
polarizing coil (terminals 7 and 8) unshorted.
coil (terminals 4 and 5) and check that the unit does not operate.
If the unit does not satisfy the above conditions, rotate the core to a position
which causes it to do so.
at the bottom of the unit and turning the core by means of the slotted bearing screw.
This screw should be held securely in position when the nut is retightened.
Keep in mind that thirty amperes will cause the current coils to overheat if left on
too long. Therefore, leave the test current on only for short intervals and allow
sufficient time between tests for the coils to cool.

Clutch Adjustment

The connections shown in Fig. 24 for the polarity check can also be used in making
the clutch adjustment. The fixed resistor should be capable of controlling the current
*Indicates Revision
Adjust the spiral spring until the moving contact apm is in a neutral
Wind the backstop screw inward until the moving and
Unwind the backstop screw 2/3 turn and tighten the locknut which
Apply current to terminals 4 and 7 and adjust the
The adjustment of the core is made at the factory,
The core can be turned by loosening the large hexagonal nut
GEK-49822
Unwind the backstop screw so that the moving
Adjust the tension of each low gradient
Finally, adjust the tension on the
Supply 30 amperes through the operating
22
Loosen the locknut which
Loosen the locknut of the
Such torques can be
Wind