Chauvin Arnoux C.A 6456 Bedienungsanleitung Seite 269

Characteristics of calculation of short-circuit current I
Display range 400 A
Resolution
Accuracy Resistances, impedances :
Accuracy values indicated for earth measurements in a live condition (see § 4.2.5)
Short-circuit current :
Accuracy of impedances + accuracy of measuremnt of voltage U
Calculation formula
4.3.5.2 Influencing quantites
Same as for earth measurements in a live condition (cf. § 4.2.5.2)
4.3.6 W 4.3.6 WARNINGS OR ERROR REPORTS (ZLOOP 4.3.6 WARNINGS OR ERROR REPORTS (ZLOOP
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 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 PRÉPARA PRÉPARA PRÉP ARATION DE LA ARA TION DE LA TION DE LA TION DE LA MESURE (BRANCHEMENT)
PREP PREPARA PREPARA ARA ARATION FOR THE MEASUREMENT (CONNECTION) TION 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
REF
=> Set the switch to ZLINE,
=> Connect the line power plug (or 2 separate cables) to the installation to be tested.
=> Activate the alarm by pressing the ALARM key,
=> Compensate of the measuring cables (see § 3.3)
The connection diagrams are the same as for earth measurements in a live condition, but without the voltage
or current probe or the connection to terminal PE (if this connection is made, it is not taken into account) :
see § 4.2.2.
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:
k
4000 A
0,1 A 1 A
I = U / Z
K REF LOOP
LOOP MEASUREMENTS)
MESURE (BRANCHEMENT)
(see § 3.2),
L
ou R (see § 4.3.2),
L L
to be used to calculate short-circuit currents
73
40 kA
10 A
, if it is used
mes
(ou Z )
LINE