HT instruments MACROTEST 5035 - Manual (Page 32)

MACROTEST 5035
EN - 31
4.4.2. Mode "P-N"
1. Select
P-N mode by means of the FUNC key.
2. If possible disconnect all low impedance loads downstream the point at which the
measurement is to be taken, as such an impedance would be in parallel with the line
impedance to be measured.
3. Connect the 3 black, blue and green connectors of the three-terminal shuko cable or of the
single cables in the corresponding input terminals of the instrument B1, B3, B4 (see
possible connections in the following pictures). When using untied cables connect the
crocodiles to the free ends of the cables.
B2 B3 B4 B1
P
Instrument connection for 230V single-phase or
two-phase line impedance measurement
B2 B3 B4 B1
L1
L2
L3
N
Instrument connection for line impedance
measurement in a 400V three-phase system
4. Connect the shuko plug into a 230V 50Hz socket or the crocodiles to the conductors of
the three-phase system (see previous pictures).
5. Press
the
START/STOP key. The instrument starts the test.
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.
LOOP
1.07
Ω
P-N
223
V
214
A
CAUTION
The measurement of Phase-Neutral impedance entails the following of a
current of about 6A between the above said conductors. This may cause the
tripping of magnetothermal RCDs with nominal value lower than 10A. If
necessary effect the test upstream the RCD itself.
Calculation formula of prospective short circuit current:
PN
N
CC
Z
U
I
=
where U
N
= phase to neutral voltage 127V if V
meas
≤ 150V; 230V if 150V < V
meas
≤ 265V
SAVING: The tests can be stored pressing the SAVE key twice
(according to paragraph 5.1).
Value of phase to
neutral line
impedance
expressed in
Ω.
Phase to neutral
effective voltage
value expressed
in Volt.
Effective value of the phase to neutral prospective
short circuit current expressed in Ampere
calculated according to the following formula.
SAVE
START
STOP