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 4: Resistance of earth connection and equipotential bonding (IEC 61557-4:2007).
交流1000V和直流1500V以下低压配电系统的电气安全.保护措施的试验、测量或监测设备.第4部分:接地连接和等电位连接的电阻(IEC 61557-4-2007)