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Low-Voltage Power Circuit Breakers
Table of Contents
Description
SECTION 1-lntroduction
1.1
1.2
Frame Size
Operation
Mounting
Trip Device
Short Circuit Ratings
SECTION 3-8torage, Safety and
Maintenance
3.1
3.2
3.3
Storage
Safety
Maintenance
SECTION 4-Breaker Operation
4.1
4.2
4.2.1
4.3
4.3.1
4.3.2
4.4
4.5
Manual Closing
Electrical Closing
Alternate Control Circuit
Connections
Stationary Breaker
Drawout Breaker
Tripping
Charging and Closing Using
the Maintenance Handle
SECTION 5-Contact Maintenance
5.1
5.1.1
5.1.2
5.2
5.2.1
5.3
5.4
5.5
5.5.1
5.5.2
5.6
5.7
5.8
5.9
5.10
5.10.1
5.10.2
5.10.3
5.10.4
5.11
Slow Closing the Breaker
Electrical Breaker
Manual Breaker
Arc Ouencher Removal and Inspection
Removal and Replacement
Separation of Front and Back Frames
Back Frame Assembly
Measuring Contact Force
Stationary Arcing Contacts
Stationary Main and Intermediate Contacts
Measuring Contact Wipe
Adjusting Contact Wipe
Measuring Contact Open Gap
Checking Contact Sequence
Replacement of Contacts
Stationary Arcing Contacts
Movable Arcing Contacts
Movable Main and Intermediate Contacts
Stationary Intermediate and Main Contacts
Assembly and Adjustment of Crossbar
© 1993 GEN ERAL ELECTRIC COMPANY
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4
Inspection and Maintenance
4
Renewal Parts ...........•.................... 4
SECTION 2-General Description
2.1
2.2
2.3
2.4
2.5
Page
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" 12
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Page
Description
SECTION 6-Breaker Maintenance
6.1
6.2
6.3
6.3.1
6.3.2
6.3.3
6.4
6.4.1
6.4.2
6.4.3
6.4.4
6.5
6.5.1
6.5.2
6.5.3
6.6
6.7
Safety Precautions
Lubrication
Breaker Mechanism Adjustments
Trip Latch
Latch Buffer
Reset Latch Bearing and Prop
Electrical Mechanism
Control Components
Charging Motor
Motor Operator Unit
Spring Discharge Interlock
Manual Mechanism
Mechanism Part Replacement
Ratchet Pawl Replacement
Adjustments
Drawout Mechanism
Drawout Mechanism Lock
,
SECTION 7-Accessories
7.1
7.1.1
7.1.2
7.2
7.2.1
7.3
7.3.1
7.3.2
7.4
7.4.1
7.4.2
7.5
7.5.1
7.5.2
7.6
7.7
7.7.1
7.8
7.8.1
7.9
7.9.1
7.9.2
Primary Disconnects
AKR 75/100
AKSIAKST 50
Secondary Disconnects
Replacement
Auxiliary Switch
Replacement
Adjustments
Shunt Trip
Replacement
Adjustment
Undervoltage Device
Replacement
Adjustment
Static Time-Delay Undervoltage
Electric Lockout Device
AdJustment
Bell Alarm Device
Adjustment
Open Fuse Lockout Device
Coil Replacement
Adjustments
SECTION 8-Type SST Overcurrent
T'
.
np Devlce
8.1
8.2
8.2.1
8.2.2
8.3
8.4
8.4.1
Programmer Unit
Current Sensors
Replacement of Current Sensors
- AKS 50
Replacement of Current Sensors
- AKR 75/100
Flux Shift Trip Device
Troubleshooting
SST Test Set
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