Chauvin Arnoux C.A 6115N, Руководство пользователя

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2. Turn the selector switch to the LOOP “Z
S
” L-PE position for the earth loop impedance or “Z
i
” L-N for
the network impedance.
So that the fault voltage is automatically measured on the LOOP Z
S
position, connect the earth probe
to the instrument. .
In the case of simultaneous selective earth measurement at the loop (using a probe and a clamp),
connect the clamp and the PE measurement lead (white) of the cable with 3 leads as close as
possible to the earth to be measured and proceed with lead compensation before starting the
measurement!
3. Press the “TEST” button.
4. With the “MORE” button, display the extra measurements (short-circuit current (I
K
)), reference voltage
(U
REF
), loop resistance (R
S
) or (R
i
) and, if using a probe and a clamp, selective earth resistance (R
SEL
),
measurement current (I
SEL
) and fault voltage (U
F)
).
To start a new measurement, press the “TEST” button again.
To come back to the display of network voltage U
L-N
, turn the selector switch or press CHANGE or
SELECT.
Note : For measurements on three-phase systems, the loop impedance must be measured between
each phase conductor (L
1
, L
2
, L
3
), the neutral conductor and the protective conductor (PE).
NOTE: This instrument can operate at voltages of 95 to 440 V. According to the current regulations in
force, the calculation of short-circuit current (I
K
) and of earth connection voltage (U
S-PE
) must
refer to the “nominal voltage”. The instrument uses the setting chosen with the MORE, CHANGE
and SELECT buttons for calculations before starting the measurement. These settings can be
modified:
1. New nominal voltage in Europe (230/400 V) – Delivery configuration
2. Old nominal voltage in Europe (220/380 V)
3. Voltage actually measured (shown with “- - -“)
NOTE: To achieve very precise measurements of low loop or network impedances, the leads can be
compensated (see 5.11).
The following table gives the maximum loop resistance values and the minimum short-circuit current
values (based on 230 V), accounting for measurement error, to stay within the tolerated limits (see
standards).
Short-circuit current = Network voltage / Loop impedance (Maximum value displayed)
Loop impedance / Network impedance Short-circuit current
Theoretical value Max. displayed value Theoretical value Min. displayed value
0.08
Ω
0.056
Ω
2875 A 4.11 kA
0.1
Ω
0.075
Ω
2300 A 3.07 kA
0.3
Ω
0.257
Ω
766.67 A 895 A
0.5
Ω
0.473
Ω
460 A 486 A
0.7
Ω
0.6664
Ω
328.57 A 346 A
1.0
Ω
0.949
Ω
230 A 242 A
3.0
Ω
2.854
Ω
76.67 A 85.5 A
5.0
Ω
4.73
Ω
46 A 48.6 A
10.0
Ω
9.49
Ω
23 A 24.2 A
15.0
Ω
14.25
Ω
15.33 A 16.1 A