4.
8
BREAKER OPENING
THE BREAKER CAN BE OPENED BY PRESSING THE MANUAL TRIP
BUTTON WHICH OPERATES DIRECTLY ON THE TRIP SHAFT OF THE
BREAKER OR BY PRESSING THE ELECTRICAL TRIP BUTTON (ON
ELECTRICALLY OPERATED UNITS) WHICH ACTIVATES THE TRIP COIL.
ALL METHODS OF TRIPPING FUNCTION BY ROTATING THE
BREAKER TRIP SHAFT. THE TRIP LATCH, ATTACHED TO THE SHAFT IS
ROTATED TOWARD THE REAR OF THE BREAKER, FREEING THE TRIP
LATCH BEARING. THIS ALLOWS THE UPPER PORTION OF THE CLOSING
MECHANISM LINKAGE TO COLLAPSE AND THE ENERGY STORED IN
THE MOVING CONTACT SPRINGS AND THE CLOSING SHAFT TORSION
SPRING RAPIDLY OPENS THE CONTACTS.
OTHER DEVICES WHICH OPERATE TO OPEN THE BREAKER ARE
SHUNT TRIP COILS FOR REMOTE OR OVERCURRENT PROTECTION
TRIPPING, UNDERVOLTAGE TRIP, DOOR INTERLOCK, FACEPLATE OR
CELL KEY INTERLOCKS AND THE ANTI-SINGLE PHASE DEVICE.
FIG. 4.8 BREAKER OPENING
