BS EN 61557-9:2015

This standard BS EN 61557-9:2015 Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. Equipment for testing, measuring or monitoring of protective measures is classified in these ICS categories:

• 29.080.01 Electrical insulation in general
• 17.220.20 Measurement of electrical and magnetic quantities
• 25.040.40 Industrial process measurement and control

This part of IEC 61557 specifies the requirements for the insulation fault location system (IFLS) which localizes insulation faults in any part of the system in unearthed IT a.c. systems and unearthed IT a.c. systems with galvanically connected d.c. circuits having nominal voltages up to 1 000 V a.c., as well as in unearthed IT d.c. systems with voltages up to 1 500 V d.c., independent of the measuring principle.

IT systems are described in IEC 60364‑4‑41 amongst other literature. Additional data for a selection of devices in other standards should be noted.