Fluke 1625 user manual Measurement of Earthing Resistances

Models: 1625

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Figure 7. Measurement of Interference - Voltages and Frequencies

1625

Users Manual

 

1625 EARTH / GROUND TESTER

 

 

START

 

 

H/C2

 

 

TEST

 

 

 

 

 

DISPLAY

 

 

S/P2

 

 

MENU

 

 

 

 

 

 

AC

 

 

 

 

Earth/Ground Resistance 300 k

Resistance

DC Low Resistance 3k

 

 

 

300 k

 

 

 

RA

R

R

 

 

 

4 POLE

2 POLE

 

 

 

 

 

2 POLE

 

 

 

3 POLE

 

 

 

 

4 POLE

 

4 POLE

 

 

CHANGE

3 POLE

 

ES/P1

 

 

ITEM

 

 

 

 

 

OFF

 

 

 

 

SELECT

 

 

E/C1

 

 

 

 

 

 

 

Auxiliary

 

 

 

 

 

earth

 

 

 

Earth

Probe

electrode

 

 

 

electrode

 

 

 

 

 

>20 m

>20 m

 

 

 

 

 

 

edw010.eps

Figure 7. Measurement of Interference - Voltages and Frequencies

Measurement of Earthing Resistances

This instrument is equipped with a 3 pole as well as a 4 pole resistance meas- urement which renders measurements of resistances of earthing systems possi- ble, as well as measurements of the soil resistivity of geological strata. A spe- cific description of the different applications is given further on in this manual. As a special function, the instrument offers measurements with an external current transformer, with which a measurement of single resistance branches in interlinked networks (lightning protection and high voltage pylons with ca- bling) can be performed without seperating parts of the system.

To ensure most feasible interference suppression during measurements, the instrument is equipped with 4 measuring frequencies (94 Hz, 105 Hz,

111 Hz, 128 Hz), with automatic switch over if necessary (AFC - Automatic Frequency Control). The corresponding measuring frequency used for a spe- cific measurement can be called and displayed with "DISPLAY MENU" after the measurement. Additionally, one of the four measuring frequencies can be selected and permanently set in special cases. In that case, in order to stabilize the display, an average measurement can be carried out for up to 1 minute by keeping the ”START TEST" button pressed.

To determine the earthing impedance (R*) a measurement with a frequency close to the mains frequency (55 Hz) is carried out. At the activation of R* through user's code, this measuring frequency is activated automatically.

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Fluke 1625 user manual Measurement of Earthing Resistances, Measurement of Interference - Voltages and Frequencies