METREL EasiPLUS MI 3000 User Manual

MI 3000 EasiPLUS IT supply systems
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either at the neutral point or at midpoint of the system or at an artificial neutral point.
The latter may be connected directly to earth if the resulting impedance to earth is
sufficiently high at the system frequency. Where no neutral point or mid-point exists a
line conductor may be connected to earth through high impedance.
133 V
133 V
L1
L2
230 V
133 V
L3
230 V
230 V
Optional
high
impedance
N (Optional) IMD
Figure B.1: General IT supply system
 Three phase star connection, optional delta connection.
 Optional neutral line.
 Single-phase connection is also possible.
 Various system voltages – not only three phase 230 V as indicated above.
 One faulty connection of any line to PE is treated as first fault and is regular but it
has to be repaired as soon as possible.
 IEC 60364-4-41: In IT systems the following monitoring devices and protective
devices may be used:
- Insulation monitoring devices (IMDs),
- Residual current monitoring devices (RCMs),
- Insulation fault location systems,
- Overcurrent protective devices,
- Residual current protective devices (RCDs).
Note:
 Where a residual current operating device (RCD) is used, tripping of the RCD in
the event of a first fault cannot be excluded due to capacitive leakage currents.
Testing of IT supply system is slightly different to standard tests in TN / TT system.

METREL EasiPLUS MI 3000 Specifications

General

Brand	METREL
Model	EasiPLUS MI 3000
Category	Test Equipment
Language	English