Manual

GSC53N - GSC57 - ZG47
EN - 40
6.4. LOOP : MEASUREMENT OF LINE IMPEDANCE, FAULT LOOP
IMPEDANCE, PROSPECTIVE SHORT CIRCUIT CURRENT
CALCULATION AND PHASE SEQUENCE INDICATOR
Turn the switch on LOOP position.
The F1 key permits to select one of the following measuring modes:
 Mode "P-N" (the instrument measures the impedance between the phase
and neutral conductors and calculates the phase to neutral prospective
short circuit current).
 Mode "P-P" (the instrument measures the impedance between two
phase conductors and calculates the phase to phase prospective short
circuit current).
 Mode "P-PE" (the instrument measures the impedance between the
phase and protective conductors and calculates the phase to earth
prospective short circuit current).
 Mode "R
A
" (the instrument measures the impedance between the
phase and protective conductors with a test current of 15mA in order to
avoid RCD tripping and calculates the phase to earth prospective short
circuit current).
 Mode " " (the instrument detect the Phase Sequence in a three-phase
system).
WARNING
Never disconnect the test leads from the circuit under test when the
message " MEASURING " is displayed.
6.4.1. High resolution Impedance measurement (0.1m )
The GSC53N, GSC57 and ZG47 models can be connected to an external optional accessory
(IMP57) capable of measuring high resolution impedance close to a power transformer.
The high Resolution impedance measurement is available inside the LOOP P-P, P-N, P-PE
modes by mean Un/IΔn key. If You enable the High Resolution Impedance Measurement
mode without connecting IMP57 the following screen will be displayed (e.g.: Loop P-N):
LOOP
29.01.04
Z=-----
R=-----
X=-----
IkSTD=----A
V1-2= 0V
FRQ= 0.0Hz
NO IMP57
P-N
Z2
FUNZ
ZSTD
ICAL
RMT
For further details regarding IMP57 use and technical characteristics please refer to IMP57
user's manual or HT web site www. htitalia.com.