Deals with single-phase or polyphase, air-cooled (natural or forced) portable inverters having a rated supply voltage not exceeding 60 V ripple-free d.c. and an alternating current (a.c.) output where the rated output does not exceed 3 kVA, the rated output voltage is within the range 50 - 500 V a.c, the rated frequency of the output is within the range 40 - 100 Hz. Portable inverters may be provided with facilities for fixing to a surface. This Standard is applicable to inverters of the following types: isolated inverters, equipotentialy bonded inverters, RCD protected inverters. These inverters are for household and similar use, use on construction sites, or providing an independent supply to electrical installations in buildings, vehicles, caravans, boats and the like. They may be fitted with terminals for the connection of d.c. supply or a power supply cord fitted with battery clips or an automobile cigarette lighter plug or other d.c. plug.