HT instruments SIRIUS89N - Manual (Page 40)

SIRIUS89N
EN - 38
6.4.2. Measurement procedure and results of "P-N" mode
1. Select
P-N mode by means of the F1 key.
2. Connect the Black, Green and Blue connectors of the three-terminal shuko cable or
of the split cables to the corresponding input terminals of the instrument
B1, B3, B4
Instrument connection for P-N test in a 230V
single-phase System
Instrument connection for P-N in a 400V three-
phase system
3. Connect the shuko plug into a 230V 50Hz socket or the crocodiles to the
conductors of the three-phase system (see previous pictures).
4. If possible disconnect all low impedance loads downstream the point at which
the measurement is to be taken, as such impedances would be in parallel with
the line impedance to be measured.
5. Press the
START key. The instrument starts the test.
CAUTION
The measurement in a 230V System make flow a test current of 6A approx.
This may cause the tripping of magnetic protection switch with nominal
value lower than 10A. If necessary effect the test upstream the switch.
Never disconnect the test leads when the message
"MEASURING" is
displayed.
LOOP 05.06.01 Value of phase to neutral line
impedance expressed in
Ω.
At the end of the test
the instrument emits a
double sound signal
indicating that the test
is correctly
terminated
and
displays the values
alongside.
Value of the phase to neutral
prospective short circuit
current expressed in Ampere
calculated according to the
following formula.
1.07
Ω
215A
FRQ=50.0HZ
VP-N=231V VP-PE=231V
P-N
!
Working mode FUNC Z2
Ω
Formula for calculation of prospective short circuit current:
PN
N
CC
Z
U
I
=
where U
N
= Nominal phase to neutral voltage = 127 if V
meas
≤150
230 if 150V< V
meas
≤250
This result can be stored pressing the
SAVE key twice (according to paragraph 9.1).
START
STOP