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GEI-83910
free to roll up the inc1 ined tube.
Thus, the moving contact comes to rest with
substantially no rebound or vibration.
The moving contacts are supported on a molded plastic arm that is attached to
the rotor shaft.
The arm is held from rotating freely by a control spring.
This
spring maintains a torque in the direction to hold the normally-open contacts open
by a magnitude that determines the pickup of the unit.
B.
TRIP UNIT (G-2)
This is the middle unit of the CLPG relay and is similar in construction to
the Gl unit previously described.
This unit has two electrically separate
contacts.
The 1 eft-hand contact is closed when the unit is de-energ i zed.
When
energi zed, the unit operates to open its 1 eft-hand contact and then closes its
right-hand contact.
It further differs from the Gl unit as follows: -
The Gl unit has
its corner coils and side coils connected
in series
internally.
However, the G2 unit side- and corner-coil connections are brought out
to a tap block located at the side of the G2 unit.
This tap block arrangement
permits the G2 unit coils to be connected in series or parallel, depending on the
tap chosen.
This allows the unit to have two ranges of pickup.
Both the normally-open and normally-closed contacts of the G2 unit are of the
barre 1-type construct ion previ ous1 y descri bed.
Furthermore the G2 unit does not
use an auxiliary current transformer.
C.
DIRECTIONAL UNIT (GO)
This is the bottom unit of the CLPG relay.
It has 2 electrically separate
contacts of the barrel-type construct i on previ ous 1y descri bed.
When de-energ i zed,
the right-hand contact is closed.
When energized in the tripping direction, the
unit operates to open the right-hand contact and then closes the left-hand contact.
The stator has eight
1
ami nated magnet i c po 1 es project i ng inward and arranged
symmetrically around a central magnetic core.
The poles are fitted with current
and potential coils.
Three of the corner coils are connected internally to form a
single circuit for current polarization.
Each of these coils has two windings, one
of which carries the polarizing current.
The other winding is connected in series
with the corresponding winding of each of the other two coils, with a capacitor.
The resultant flux from these coils is shifted in phase with respect to the
operating-circuit flux.
The fourth corner coil is a potential coil for potential
polarization.
The four side coils are connected together to form the operating-
current circuit.
In the annular air gap between the poles and central core is the cylindrical
cup-like part of the aluminum rotor, which turns freely in the gap.
The rotor
shaft is supported at the bottom by a steel pivot that projects downward through a
bronze guide beari ng mounted in the end of the shaft.
The shaft carri es the
movable contact arm through which the contact circuits are completed.
D.
AUXILIARY UNIL.0DIX)
This unit is located in the rear of the CLPG12C relay, just below the upper
unit.
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