HT instruments HT78 User Manual
Page 2

HT78
EN - 1
Table of contents:
1. SAFETY PRECAUTIONS AND PROCEDURES ..........................................................2
1.1.
Preliminary ........................................................................................................................ 2
1.2.
Before use......................................................................................................................... 3
1.3.
After use............................................................................................................................ 3
1.4.
Measuring (overvoltage) categories definitions................................................................. 3
2. GENERAL DESCRIPTION ...........................................................................................4
2.1.
TRMS and MEAN VALUE measuring instruments............................................................ 4
2.2.
TRUE ROOT MEAN SQUARE VALUE and CREST FACTOR definitions........................ 4
3. PREPARATION FOR USE ...........................................................................................5
3.1.
Initial.................................................................................................................................. 5
3.2.
Power supply..................................................................................................................... 5
3.3.
Calibration ......................................................................................................................... 5
3.4.
Storage.............................................................................................................................. 5
4. OPERATING INSTRUCTIONS.....................................................................................6
4.1.
Instrument description....................................................................................................... 6
4.1.1.
Front panel.................................................................................................................................. 6
4.2.
Description of parts ........................................................................................................... 7
4.2.1.
Range and ON/OFF selector...................................................................................................... 7
4.2.2.
D-H key....................................................................................................................................... 7
4.2.3.
FILTER selector.......................................................................................................................... 7
4.2.4.
LOCK selector ............................................................................................................................ 7
4.2.5.
AutoPowerOFF........................................................................................................................... 7
4.2.6.
DC analogical output .................................................................................................................. 8
4.3.
How to perform the measurements ................................................................................... 9
4.3.1.
AC Current measurement........................................................................................................... 9
4.3.2.
Leakage current measurement on Single phase system ......................................................... 10
4.3.3.
Leakage current measurement on Three phase system.......................................................... 11
5. MAINTENANCE .........................................................................................................12
5.1.
General informations ....................................................................................................... 12
5.2.
Batteries replacement ..................................................................................................... 12
5.3.
Cleaning .......................................................................................................................... 12
5.4.
End of life ........................................................................................................................ 12
6. TECHNICAL SPECIFICATIONS ................................................................................13
6.1.
Characteristics................................................................................................................. 13
6.1.1.
Safety........................................................................................................................................ 13
6.1.2.
General data............................................................................................................................. 13
6.2.
Environmental conditions ................................................................................................ 14
6.2.1.
Climatic conditions.................................................................................................................... 14
6.3.
Accessories ..................................................................................................................... 14
6.3.1.
Standard accessories ............................................................................................................... 14
7. SERVICE....................................................................................................................15
7.1.
Warranty conditions......................................................................................................... 15
7.2.
Service ............................................................................................................................ 15