JUPITER
IT - 20
5.7. MEASUREMENT
OF
LINE/LOOP IMPEDANCE
This function is performed in compliance with standards CEI 64-8 612.6.3, IEC/EN61557-3
and allows measuring line impedance, fault loop impedance and the assumed short-circuit
current (see § 9.3). The following operating modes are available:
L-N
the instrument measures line impedance between phase and neutral conductor
and calculates the assumed phase-to-neutral short-circuit current.
L-L
the instrument measures line impedance between two phase conductors and
calculates the assumed phase-to-phase short-circuit current.
L-PE
the instrument measures the fault loop impedance between phase and earth
conductor Ra
and calculates the assumed phase-to-earth short-circuit
current).
CAUTION
The maximum input AC voltage is 690V to earth and between inputs. Do
not measure voltages exceeding the limits given in this manual.
Exceeding voltage limits could result in electrical shocks to the user and
damage to the instrument.
The measurement of overall earth resistance involves the circulation of a
current of approx.
100mA
between phase and earth according to the
technical specifications of the instrument (see § 7.1). This could cause the
tripping of possible protections with lower tripping currents.
Fig. 23: Use of the instrument for measuring Loop L-PE impedance with cable provided
with Schuko plug