HT instruments SPEED418 - Manual (Page 17)

400 Series
EN - 16
6.2. LOWOHM: CONTINUITY TEST OF EARTH LEADS WITH 200mA
This function is performed in compliance with standard IEC/EN61557-4 and allows
measuring the resistance of protective and equipotential conductors. The following
operating modes are available:
 CAL compensation of the resistance of the cables used for measurement. The
instrument automatically subtracts the value of cable resistance from the
measured resistance value. It is therefore necessary that this value is measured
(by means of the CAL function) each time the test cables are changed or
extended
 AUTO the instrument performs two measurements with inverted polarity and displays
the average value of the two measures. Recommended mode for continuity test
 R+ measurement with positive polarity and with the possibility of setting a test
duration time. In this case, the operator may set a measuring time long enough
to be able to move the protective conductors while the instrument is performing
the test, in order to detect a possible bad connection
 R- measurement with negative polarity and with the possibility of setting a test
duration time. In this case, the operator may set a measuring time long enough
to be able to move the protective conductors while the instrument is performing
the test, in order to detect a possible bad connection.
CAUTION
The continuity test is performed by supplying a current higher than
200mA in case the resistance is not higher than ca. 10
 (including
resistance of the test cables saved in the instrument as offset after
performing the calibration procedure). For higher resistance values, the
instrument performs the test with a current lower than 200mA.
Fig. 6: Instrument connection by means of single cables and remote probe
1. Press the MENU key, move the cursor to
LOW
 in the main menu by means of the arrow
keys (,) and confirm with ENTER.
Subsequently the instrument displays a screen
similar to the one reported here to the side.
L O W 
- - - -

R + R -
- - - -  - - - - 
- - - m A - - - m A
CAL 4.00  ----
Func Lim CAL