2-Wire Loop Measurement (Z Line) - Chauvin Arnoux C.A 6454 Manual De Instrucciones

The characteristics of loop measurements with 3 wires, with (
the same as those of earth measurements in a live condition, with or without tripping, respectively:
see § 4.2.5.1.
Characteristics of calculation of short-circuit current I
Display range
Resolution
Accuracy
Calculation formula
4.3.5.2 INFLUENCING QUANTITIES
Same as for earth measurements in a live condition (cf. § 4.2.5.2))
4.3.6 WARNINGS
MEASUREMENTS)
Preliminary remark: The complete list of coded errors is given in § 7.
Same as for earth measurements in a live condition, except for the rod and the current probe
measurement, which do not apply to loop measurements: see § 4.2.6.

4.4 2-WIRE LOOP MEASUREMENT (Z LINE)

4.4.1 DESCRIPTION OF THE FUNCTION
This function measures the line impedance between conductors "L" and "N" of the power network.
This measurement can also be used to calculate short-circuit currents, in order to size fuses and
circuit breakers.
It is possible to check the impedance between conductors "L" and "PE" or between two "L"
conductors, but the measuring cables must systematically be connected to terminals "L" and "N" of
the measuring instrument.
4.4.2 PREPARATION FOR THE MEASUREMENT (CONNECTION)
→ If necessary, in "SET-UP" mode:
- set the threshold voltage U
- set the alarm threshold Z
- choose the value of U
→ Set the switch to ZLINE,
→ Connect the line power plug (or 2 separate cables) to the installation to be tested.
400 A
0,1 A
Resistances, impedances:
Accuracy values indicated for earth measurements in a live condition (see
§ 4.2.5)
Short-circuit current:
Accuracy of impedances + accuracy of measurement of voltage U
used
OR ERROR
(see § 3.2),
L
or R (see § 4.3.2),
L L
to be used to calculate short-circuit currents (see § 4.3.2),
REF
) or without tripping (
:
K
4000 A
1 A
I = U / Z (or Z
K REF LOOP
REPORTS
67
40 kA
10 A
mes
)
LINE
(ZLOOP
) are
, if it is
LOOP