Guide to Low Resistance Testing

Megger Sweden

Guide to Low Resistance Testing

Publicerad: 29 juni 2020 · Kategori: Pdf-kataloger

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A guide to low resistance testing Contents HOW IS LOW RESISTANCE MEASURED?12 INTRODUCTION3 Brief history of low resistance ohmmeters4 WHY MEASURE LOW RESISTANCE? 4 What is a low resistance measurement?  5 What does a low resistance measurement tell the user? 5 What problems create the need for a test? 5 Saving money by low resistance testing 5 Industries with significant resistance problems6 What equipment needs low resistance testing Motor armature Automotive assembly Power generation and distribution 6 12 Two wire measurements 13 Three wire measurements 13 Four wire measurements 13 D.C. vs. A.C.  Repeatability20 13 The difference between continuity and low resistance  14 Test modes 14 Models designed in the 1970s and 1980s 14 10 amp models 14 100 amp and above models 14 HOW DOES A LOW RESISTANCE OHMMETER OPERATE? 15 7 7 Uninterruptible power supply battery straps 7 Cement plants and other raw material processing applications 8 Circuit breakers 8 Aircraft assembly 8 9 Safety15 Test on de-energized samples 15 Use and misuse of low resistance ohmmeters16 Motor bar to bar tests 29 Battery strap tests 31 Trending  Ramp testing 31 Wheatstone and kelvin bridges 32 21 Circuit breakers 21 Stand-by battery back-up systems 21 Measuring components of a system  23 High currents in low resistance measurement23 Wheatstone bridge 32 Kelvin bridge 32 DLRO microohm and milliohm applications lists 33 MEGGER PRODUCTS OVERVIEW Potential sources of...