Vigilohm System - engineering site - Schneider Electric

Vigilohm: presentation
insulation monitoring and associated functions
continuity of supply
Continuity of supply is a need that must
always be satisfied by electrical installations,
along with the protection of life and property.
The IT system provides the best guarantee
in terms of continuity of supply. Even when a
first insulation fault is present, the installation
can continue to supply power without
endangering human life. The first fault must
however be detected and repaired before a
second fault occurs.
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principle
Insulation monitoring is provided on IT
systems to detect and indicate insulation
faults as soon as they occur.
The basic function is carried out by an
Insulation Monitoring Device (IMD), also
referred to in certain documentation as a
permanent or continuous insulation monitor
(PIM or CIM respectively). The monitoring
device injects a DC or low-frequency
AC voltage between the installation and
earth. The insulation resistance is determined
from the resulting current. This technique can
be used on all types of installations: AC, DC,
rectified, mixed AC/DC, etc.
DB100664
measuring, indicating and
locating insulation faults
Vigilohm System, with or without a
communication bus, fulfils the following
basic functions:
c measurement of insulation level on all
types of installations
c manual or automatic locating of insulation
faults.
Vigilohm System with a
communication bus
The communication bus adds the following
possibilities:
c measurement of the insulation resistance
and earth leakage capacitance of each
circuit
c centralisation of fault locating
measurements on the IMD display units
c communication with a supervisor
(transmission of measurements and
reception of settings).
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