HT instruments SIRIUS87 - Manual (Page 36)

SIRIUS 87
EN - 34
4.4.1. High resolution Impedance measurement (0.1m )
SIRIUS 87 is connectable to an external optional accessory (IMP57) useful for high resolution
impedance measurement 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:
LOW  LOOP


no
con ins

For further details regarding IMP57 use and technical characteristics please refer to IMP57 user
manual or HT web site
www. ht-instruments.com.
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 Fig. 9,
Fig. 10). When using untied cables connect the crocodiles to the free ends of the cables.
Fig. 9: Connection for P-N impedance
measurement Single/Two phase 230V
Fig. 10: Connection for P-N impedance
measurement Three-phase 400V