KRB-5404
87
6-2-3. Stationary contact
The following describes how to replace the stationary contact. Fig. 78 shows the general view around the stationary contact.
Fig. 78 General view around the stationary contact
1) Make preparations for parts replacement. Refer to section 6-2-1.
2) Unscrew the current sensor mounting screws and remove the current sensor and the power supply CT located behind the sensor.
Take care not to exert undue force on the control wire between the current sensor and the power supply CT. To remove the
current sensor, hold the top of the sensor, then tilt and pull it out in a slanting direction as shown in Fig. 79.
Fig. 79 Stationary contact
3) Unscrew stationary contact mounting screws A and B.
Mold base
Moving contact tip
Moving contact
Insulated operating rod
Moving contact mounting screw,
Hex. socket head M8 × 30 (6-16)
(M8 × 25 for AR208S only
)
with spring washer
Tightening torque: 14.7 N·m
Stationary contact mounting screw A,
Pan head M6 × 30(12-32)
with spring and flat washers
Tightening torque: 4.7 - 5.9 N·m
Stationary contact mounting screw B,
Pan head M6 × 20 (12-32)
with spring and flat washers
Tightening torque: 4.7 - 5.9 N·m
Main circuit contact
Stationary contact
Stationary contact tip
Engagement measuring hole
Current sensor mounting screws,
Pan head M4 × 12 (6-16)
with spring and flat washers
Tightening torque: 1.3 - 1.7 N·m
Stationary contact mounting screws A,
Pan head M6 × 30 (12-32)
with spring and flat washers
Tightening torque: 4.7 - 5.9 N·m
Stationary contact mounting screws B,
Pan head M6 × 20 (12-32)
with spring and flat washers
Tightening torque: 4.7 - 5.9 N·m
Allen wrench holes
(marked with while lines)
Engagement measuring hole
(marked with while line)
Current sensor
Removing the current sensor