标准摘要
[中文适用范围]： IEC 61557的本部分规定了适用于利用被测电路加载时的电压降来测量相导体与保护导体之间、相导体与中性线之间或两相导体之间环路阻抗的设备的要求。 [外文原描述]： This part of IEC 61557 specifies the requirements applicable to equipment for measuring the loop impedance between a phase conductor and the protective conductor or between a phase conductor and neutral or between two phase conductors by using the voltage drop when the circuit under test is loaded. This second edition cancels and replaces the first edition published in 1997. This edition constitutes a technical revision. The following changes were made with respect to the previous edition: a) definitions complemented; b) revision of some requirements; c) addition of information on operating instructions; d) addition of new influence quantities E9 and E10.
英文名称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 - Part 3: Loop impedance