BS EN 61557-9-2015 不超過1000 V交流和1500 V直流的低壓分布系統的電氣安全性.防護措施測試,測量和監控設備.第9部分:IT系統中絕緣故障的定位設備
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. Equipment for insulation fault location in IT systems