Operation Manual

5.9 Resistance to earth (R

) ( BENNING IT 120 B only)

The BENNING IT 120 B allows resistance to earth measurement using 3-wire measuring me-

thod (earthing set). Consider the following instructions when performing resistance to earth

measurement:

- The probe (S) is positioned between the earth electrode (E) and auxiliary earth electrode (H) in

theearthreferenceplane(seegure5.45).

- The distance from the earth electrode (E) to the auxiliary earth electrode (H) must be at least 5

timesthedepthorlengthoftheearthingelectroderod(seeg.5.45).

How to perform resistance to earth measurement:

Step 1 Select R

, ERDE/ EARTH function with the function selector switch. The following menu

is displayed:

Fig. 5.44: Earth resistance measurement menu

Connect the measuring cables to the BENNING IT 120 B.

Step 2 Set the following measuring parameters and limit values:

- High limit resistance value

Step 3 Followtheconnectiondiagramshowningure5.45toperformresistancetoearthmea-

surement. Use the Help function if necessary.

(Measuring cables: H = black, S = green, E = blue)

Fig. 5.45: Measurement with the earthing set – 20 m

Step 4 Check the displayed warnings and online voltage/terminal monitor before starting the

measurement. If OK, press the TEST key. After performing, the measurement results

appear on the display together with the PASS/FAIL indication (if applicable).

Fig. 5.46: Example of resistance to earth measurement results