BS EN 61557-8:2015
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 Insulation monitoring devices for IT systems
| Standard number: | BS EN 61557-8:2015 |
| Pages: | 52 |
| Released: | 2016-06-30 |
| ISBN: | 978 0 580 81262 0 |
| Status: | Standard |
BS EN 61557-8:2015
This standard BS EN 61557-8:2015 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:
- 17.220.20 Measurement of electrical and magnetic quantities
- 29.080.01 Electrical insulation in general
- 29.240.01 Power transmission and distribution networks in general
This part of IEC 61557 specifies the requirements for insulation monitoring devices (IMD) which permanently monitor the insulation resistance R F to earth of unearthed a.c. IT systems, of a.c. IT systems with galvanically connected d.c. circuits having nominal voltages up to 1 000 V a.c., as well as of unearthed d.c. IT systems with voltages up to 1 500 V d.c. independent from the method of measuring.
IT systems are described in IEC 60364‑4‑41 amongst other literature. Additional data for the selection of devices in other standards should be noted.
Various standards specify the use of IMDs in IT systems. In such cases, the objective of the equipment is to signal a drop in insulation resistance R F below a minimum limit.
IMDs according to this part of IEC 61557 can also be used for de-energized TT, TN and IT systems or appliances.