68
→
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.
4.4.3 MEASUREMENT PROCEDURE
In the case of 2-wire loop measurements, there is no monitoring of the potential of terminal
PE nor the installation PE line.
Loop measurements with 2 wires are identical to loop measurements with 3 wires except as follows:
- the voltage between the TEST key and PE is not measured: only the potential between
terminals L and N is measured;
- there is no monitoring of U
NPE
which enable the measurement.
The instrument measures voltage U
LN
and voltages U
LPE
, U
NPE
if terminal PE is connected.
Note: for measurements on three-phase systems, this impedance must be measured between each
phase conductor and the neutral conductor.
4.4.4 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
LN
Z
LN
L
LN
Z
LN
U
REF
I
KLN
Hz
U
LN
- - -
Z
L ALARM
R
∆
L
U
L
(1
st
press)
R
LN
Z
LN
L
LN
Z
LN
U
REF
I
KLN
Hz
U
LPE
- - -
Z
L ALARM
R
∆
PE
U
L
(2
nd
press)
R
LN
Z
LN
L
LN
Z
LN
U
REF
I
KLN
Hz
U
NPE
- - -
Z
L ALARM
R
∆
N
U
L
Pressing the
or
key once more causes a return to the initial display.
4.4.5 CHARACTERISTICS
4.4.5.1
MEASUREMENT RANGES AND ACCURACY
The particular reference conditions are the same as for 3-wire loop measurements (see § 4.3.5).
The characteristics are the same as for earth measurements in a live condition: see § 4.2.5.1.
4.4.5.2
INFLUENCING QUANTITIES
Same as for earth measurements in a live condition: see § 4.2.5.2.
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Summary of Contents for C.A 6454
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