MI 3101 EurotestAT: Instrument operation
Miscellaneous
38
4.4.2 Supply system, Isc factor, RCD standard
In the
Voltage system
menu
the following parameters can be selected:
Voltage system
Mains supply system type.
Set Isc factor
Correction factor for Isc
calculation (ksc).
RDC testing
RCD normative reference.
Figure 4.24: System parameters
Keys:
/
Select option.
/
Change the option.
TEST
Confirms selected option.
ESC
Exits to settings menu with new setup.
Mains supply systems
The following supplying systems are supported:
TT / TN (earthed systems),
IT (system insulated from earth),
110 V reduced low voltage (2 x 55
V center tap grounded),
110 V reduced low voltage (3 x 63
V three phase, star center grounded).
TN, TT and IT systems are defined in EN 60364-1 standard. 110 V reduced low voltage
systems are defined in BS 7671.
See
Appendix D
for particular characteristics of IT supply system measurements and
instrument characteristics.
See
Appendix E
for particular characteristics of 110 V reduced low voltage supply systems
measurements and instrument characteristics.
Isc factor - ksc
Short circuit current Isc in the supply system is important for selection or verification of
protective circuit breakers (fuses, over-current breaking devices, RCDs).
The default value of ksc is 1.00. Change the value as required by local regulative for
tested type of mains supply system.
Range for adjustment of the ksc is 0.20
3.00.
