Tettex MIDAS micro 2883 - Table of Contents

Introduction
I
Contents
1.1 Manual Conventions.................................................................................................. VI
1.2 Abbreviations and Definitions .................................................................................... VI
2 Introduction 1
2.1 General ...................................................................................................................... 1
2.2 Scope of Supply ......................................................................................................... 1
3 Technical Data 3
4 Safety 5
4.1 General ...................................................................................................................... 5
4.2 Personnel Safety ........................................................................................................ 5
4.3 Safety Features .......................................................................................................... 6
4.4 Safety Precautions ..................................................................................................... 6
4.5 Summary.................................................................................................................... 7
5 Theory 8
5.1 Why is Insulation Tested? .......................................................................................... 8
5.2 What is Loss Factor? .................................................................................................. 8
5.3 What is Dissipation Factor tan δ? ............................................................................... 8
5.4 The Difference between Power Factor and Dissipation Factor.................................. 10
5.5 Apparent Power, Real Power, Reactive Power ......................................................... 10
5.6 Test Instruments ...................................................................................................... 11
5.7 Evaluation of Test Results ........................................................................................ 11
5.7.1 Significance of Capacitance and Dissipation Factor .................................. 11
5.7.2 Dissipation Factor of Typical Apparatus Insulation .................................... 12
5.7.3 Dissipation Factor and Dielectric Constant of Typical Insulation Materials . 12
5.7.4 Influence of Temperature .......................................................................... 13
5.7.5 Influence of Humidity ................................................................................. 13
5.7.6 Influence of Surface Leakage .................................................................... 14
5.7.7 Electrostatic Interference ........................................................................... 14
5.7.8 Negative Dissipation Factor ....................................................................... 14
5.8 Standard Capacitor, Measuring Current & Limits ...................................................... 15
5.9 Parallel & Series Equivalent Circuits......................................................................... 16
6 Functional Description 17
6.1 System Overview ..................................................................................................... 17
6.2 V-potential point and Guarding ................................................................................. 17
6.3 Test Modes .............................................................................................................. 18
6.3.1 Test Mode „UST” for ungrounded test objects ........................................... 20
6.3.2 Test Mode „GST“ for grounded test objects ............................................... 20
6.3.3 Test Mode „GST g“ for grounded test objects with guarding (V-potential) . 21
6.4 Interference Suppression ......................................................................................... 22
7 Operation Elements 23