Chauvin Arnoux C.A 6456 Notice De Fonctionnement page 73

=> Compensate the measuring cables (see § 3.3),
=> Select the measuring current:
=> high ( ) for a greater accuracy:
- if no tripping of a earth fault breaker is foreseen (measurement made upstream of the RCDs),
- if the earth fault breaker concerned is short-circuited for greater accuracy,
=> low ( ) otherwise for a rapid check
The connection diagrams are the same as for earth measurements in a live condition, but without the voltage
or current probe (see § 4.2.2).
4.3.3 MEASUREMENT PROCEDURE
The instrument first checks the resistance of the rod and measures the voltage between PE and earth, then
measures voltages U , U , U
LN LPE NPE
If these values are correct, pressing the TEST key starts the measurement: as soon as the result is available,
it is displayed.
Note: for measurements on three-phase systems, the loop impedance must be measured between each
phase conductor, the neutral conductor, and the protective conductor.
4.3.4 MEASUREMENT RESULTS
After the measurement, the measured values and complementary results can be consulted using
the and keys.
MORE
(The quantities accessible before the measurement is made are described above, in § 4.1.4.)
Initial
display
R
LPE
Initial display
Z
LPE
R
(1 st press)
LN
Z
LN
R
nd
(2 press)
NPE
Z
NPE
Pressing the or key once more causes a return to the initial display.
MORE
Note : In non-trip mode the inductive component is not measurable due to the weak test current. The values
L , L , Z , are not displayed (display shows - - - -). The value L
LPE NPE NPE
4.3.5 CHARACTERISTICS
4.3.5.1 Measurement ranges and accuracy
Particular reference conditions :
- nominal voltage of the installation = 90 to 550V,
- nominal frequency of use = 15.3 to 65Hz,
- inductive part < 0.1 x the resistive part of the impedance measured.
The characteristics of loop measurements with 3 wires, with (
same as those of earth measurements in a live condition, with or without tripping, respectively: see § 4.2.5.1.
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.
MORE MORE MORE
nd
(1 st press) (2 press)
(3 nd
U
L
REF
LPE
I
Z
KLPE
LPE
U
L
REF
LN
I
Z
KLN
LN
U
L
REF
NPE
I
Z
KNPE
NPE
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MORE MORE
press) nd nd
(4 press) (5 press)
Hz
---- R
∆ ∆ ∆ ∆ ∆ PE
U Z U
LPE
L ALARM L
Hz
---- R
∆ ∆ ∆ ∆ ∆ L
U
Z U
LN
L ALARM L
Hz
---- R
∆ ∆ ∆ ∆ ∆ N
U
Z U
NPE
L ALARM L
is displayed in the L field.
LPE LN
) or without tripping ( ) are the