Megger MTO300 - Page 4

Operating the MTO300/330A ................................................................................................................ 20
Description of Test Sequence ................................................................................................................ 21
AUTOMATIC DISCHARGE Function ....................................................................................................... 21
DEMAGNETIZATION Function ............................................................................................................... 21
REMOTE TEST Function (MTO300 ONLY) ............................................................................................. 22
6 THREE-PHASE TRANSFORMER & WINDING RESISTANCE TESTING .............................................. 25
General ..................................................................................................................................................... 25
Procedure ................................................................................................................................................. 25
Test Form Controls - General ................................................................................................................. 28
Transformer Test Conditions .................................................................................................................. 30
Instrument Settings Button ................................................................................................................... 30
Winding Resistance Testing Methods ................................................................................................... 32
Method 1 - Resistance Test Wizard - ..................................................................................................... 32
Method 2 – Measuring Tap – All Phases Winding Resistance - ......................................................... 33
Method 3 – Measuring Individual Tap Winding ................................................................................. 34
Resistance Test Screen ............................................................................................................................ 35
7 SAVE/RETRIEVE RESULTS ................................................................................................................... 37
Retrieving Results/Test Files ................................................................................................................... 38
8 APPLICATION NOTES ......................................................................................................................... 41
Testing Delta Configured Windings ..................................................................................................... 41
Delta Winding Resistance ...................................................................................................................... 41
Temperature Correction ......................................................................................................................... 41
Temperature Entry .................................................................................................................................. 42
9 ORDERING INFORMATION / SPARE PARTS ...................................................................................... 43
10 SERVICE ............................................................................................................................................... 45
Maintenance ........................................................................................................................................... 45
Fuse Replacement ................................................................................................................................... 45
Calibration ............................................................................................................................................... 46
Repairs ...................................................................................................................................................... 47
Error Codes .............................................................................................................................................. 47
Table of contents
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MTO3XXX-UG-EN Rev 1 Feb 2018
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