CEI EN 61557-15

This part of IEC 61557 specifies requirements related to
functional safety and is based on the IEC 61508 standard series for
the realization of insulation monitoring devices (IMD) as specified
in IEC 61557-8 and for insulation fault location systems (IFLS)
according to IEC 61557-9, according to phase 10 of the IEC 61508-1
lifecycle. These devices provide safety related functions for IT
systems.

This part of IEC 61557 is:

– concerned only with functional safety requirements intended to
reduce the functional risk during the use of IMDs and IFLSs;

– restricted to risks arising directly from the device itself or
from several IMDs or IFLSs working together in a system;

– intended to define the basic safety functions provided by the
devices.

This part of IEC 61557 does not:

– deal with electrical safety according to IEC 61010-1 and the
requirements of IEC 61557-8 and IEC 61557-9;

– cover the hazard and risk analysis of a particular use of the
IMD or IFLS;

– identify all the safety functions for the application in which
the IMD or IFLS is used;

– cover the IMD or IFLS manufacturing process.

Functional safety requirements depend on the application and
should be considered as part of the overall risk assessment of the
specific application. The supplier of IMDs and IFLSs is not
responsible for the application. The application designer is
responsible for the risk assessment and for specifying the overall
functional safety requirements of the complete IT system and he
should select the functional safety level (SIL) of the IMD and/or
IFLS when their safety function is part of the functional safety
assessment in the IT system.