66
- 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
LN
, U
LPE
, U
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.
(The quantities accessible
before
the measurement is made are described above, in § 4.1.4.)
Initial
display
(1
st
press)
(2
nd
press)
(3
rd
press)
(4
th
press)
(5
th
press)
Initial display
R
LPE
Z
LPE
L
LPE
Z
LPE
U
REF
I
KLPE
H
Z
U
LPE
- - -
Z
L ALARM
R
∆
PE
U
L
(1
st
press)
R
LN
Z
LN
L
LN
Z
LN
U
REF
I
KLN
H
Z
U
LN
- - -
Z
L ALARM
R
∆
L
U
L
(2
nd
press)
R
NPE
Z
NPE
L
NPE
Z
NPE
U
REF
I
KNPE
H
Z
U
NPE
- - -
Z
L ALARM
R
∆
N
U
L
Pressing the
or
key once more causes a return to the initial display.
Note : In non-trip mode the inductive component is not measurable due to the weak test current. The
values L
LPE
, L
NPE
, Z
NPE,
are not displayed (display shows - - - -). The value L
LPE
is displayed in the
L
LN
field.
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.
MORE
MORE
MORE
MORE
MORE
MORE
MORE
Summary of Contents for C.A 6454
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