GE Industrial Solutions Power-Vac ML-20 Mechanism - Manual (Page 2)

2
PowerVac ® Vacuum Circuit Breaker
with ML-20 Mechanism
Table of Contents
Description Page
SECTION 1 −−−− Introduction
............................................ 4
1.1 Safety .............................................................................. 4
1.2 Maintenance ................................................................... 4
SECTION 2 −−−− Description
............................................... 5
2.1 General............................................................................ 5
2.2 Summary Description ...................................................... 5
SECTION 3 −−−− Receiving, Handling and
Storage
...................................................... 5
3.1 Receiving ........................................................................ 5
A. Equipment Packages................................................. 5
B. Inspecting for Damage .............................................. 5
C. Filing a Claim ............................................................. 5
3.2 Handling .......................................................................... 6
3.3 Storage............................................................................ 6
SECTION 4 −−−− Features
...................................................... 6
4.1 Safety Precautions........................................................... 6
4.2 Interlocks......................................................................... 6
4.2.1 Rating Interference Plate................................................. 6
4.2.2 Closing Spring Interlock ................................................... 6
4.2.3 Negative Interlock............................................................ 7
4.2.4 Positive Interlock Bar....................................................... 7
4.2.5 Closing Spring Gag Interlock............................................ 7
SECTION 5 −−−− Operation
.................................................. 8
5.1 General............................................................................ 8
5.2 Close Spring Charging ..................................................... 8
5.3 Closing Operation............................................................ 8
5.4 Opening Operation.......................................................... 9
5.5 Trip-free Operation.......................................................... 9
SECTION 6 −−−− Control Circuit
....................................... 9
SECTION 7 −−−− Mechanical Checking and
Slow Closing
......................................... 9
7.1 Visual Inspection.............................................................. 9
7.2 Closing Spring Charging .................................................. 9
7.3 Closing Spring Gag ..........................................................10
7.4 Slow Closing....................................................................10
7.5 Gag Plate Removal..........................................................10
SECTION 8 −−−− Dimensional Checks
.........................11
8.1 Primary Contact Erosion ..................................................11
8.2 ML Wipe Spring Compression ........................................11
8.3 Contact Gap ....................................................................11
8.4 Close Coil Plunger Gap....................................................12
8.5 Trip Coil Plunger Gap.......................................................12
8.6 Control Switch Adjustment..............................................12
Description Page
SECTION 9
−−−− Electrical Checks
................................. 14
9.1 Electrical Operation......................................................... 14
9.2 High Potential Test.......................................................... 14
9.2.1 Primary Circuit................................................................. 14
9.2.2 Secondary Circuit ............................................................ 14
9.3 Primary Circuit Resistance .............................................. 14
9.4 Vacuum Interrupter Integrity Test.................................... 14
9.5 Insulation Test................................................................. 15
SECTION 10 −−−− Checking and Installing
Breakers
................................................. 16
SECTION 11 −−−− Maintenance
....................................... 17
11.1 General ........................................................................... 17
11.1.1 PowerVac
Interrupter ...................................................... 17
11.1.2 Trouble Reporting ........................................................... 17
11.2 Service Conditions .......................................................... 17
11.3 Fault Interruptions ........................................................... 17
11.4 Contact Erosion............................................................... 17
11.5 Transfer Finger Wear ...................................................... 17
11.6 Mechanism ..................................................................... 17
11.7 Primary Insulation Parts................................................... 17
11.8 Lubrication ...................................................................... 18
11.9 Recommended Maintenance.......................................... 18
SECTION 12 −−−− Timing
...................................................... 19
SECTION 13 −−−− Opening and Closing Speed
.. 20
SECTION 14 −−−− Repair and Replacement
........... 21
14.1 General ........................................................................... 21
14.2 Replacement of Interrupter Assemblies ......................... 21
14.3 Primary Disconnect Fingers ............................................ 21
14.4 Mechanism ..................................................................... 21
14.5 Control Switches............................................................. 21
14.6 Trip Coil Replacement..................................................... 21
14.7 Closing Coil Replacement............................................... 22
14.8 Auxiliary Switch Replacement......................................... 22
14.9 Motor Replacement........................................................ 22
14.10 “Y” Relay Replacement................................................... 22
SECTION 15 −−−− Renewal Parts
.................................... 23
15.1 Ordering Instructions....................................................... 23
SECTION 16 −−−− Mechanical Adjustment
............ 23
16.1 General ........................................................................... 23
16.2 Wipe Adjustment ............................................................ 23
16.3 Contact Gap Adjustment ................................................. 23
16.4 Trip Coil Plunger.............................................................. 24
16.5 Close Coil Plunger........................................................... 24
16.6 Close Spring Discharge Interlock..................................... 24
16.7 Negative Interlock ........................................................... 24
INDEX
........................................................................................ 36
Trouble Reporting Form................................................................ 37