Manual

Table of Contents vii
7000 “A” Frame 7000A-RM001A-EN-P – January 2011
Surge Arresters ..................................................................... 5-10
Description ..................................................................... 5-10
Operation ........................................................................ 5-11
Surge Arrester Replacement ........................................... 5-11
Field Test and Care ........................................................ 5-12
PowerCage™ .........................................................................5-13
SGCT and Snubber Circuit ....................................................5-16
Uniform Clamping Pressure ..................................................5-17
Checking Clamping Pressure .................................................5-18
Clamping Pressure Adjustment .......................................5-18
Temperature Sensing .............................................................5-19
Symmetrical Gate Commutated Thyristor Replacement .......5-21
Heatsink Replacement ...........................................................5-24
PowerCage Gasket .................................................................5-25
Replacement of PowerCage Gaskets ...............................5-26
Removal of old Gasket Material .....................................5-26
PowerCage Removal .............................................................5-27
Snubber Resistors ..................................................................5-29
Testing Snubber Resistors ...............................................5-29
Snubber and Sharing Resistor Replacement ..........................5-30
Sharing Resistors ...................................................................5-32
Testing Sharing Resistors ................................................5-32
Replacing Sharing Resistor .............................................5-34
Resistance Measurements ...............................................5-34
Fiber Optic Cabling .............................................................. 5-35
Air Pressure Sensor ................................................................5-36
Air Pressure Sensor Replacement ...................................5-36
DC Link/Fan/Control Components ........................................5-37
Output Grounding Network Replacement .......................5-38
Ground Filter Component Replacement .........................5-39
Filter Capacitors ..............................................................5-40
Filter Capacitor Replacement ..........................................5-41
Testing Filter Capacitors ................................................ 5-42
First Method ............................................................ 5-42
Second Method ........................................................ 5-43
Recommended Digital Multimeters (DMM) .................. 5-45
DC Link Reactor Replacement ..............................................5-46
Fan Replacement ...................................................................5-48
DC Link Section ..............................................................5-48
Safety Notes ....................................................................5-48
Fan Installation ................................................................5-49
Top of Integral Isolation Transformer Section ................5-49
Top of Integral Line Reactor/Input Starter Section .........5-50
Impeller Maintenance (DC Link/Fan Section) ......................5-51
Impeller Removal from Motor Shaft ...............................5-51
Safety Notes ....................................................................5-51
Installation of Impeller Assembly onto Motor Shaft .......5-52
Chapter 5 Component Definition
and Maintenance
(cont.)