This accessory belongs to the Vigilohm range designed to monitor ungrounded/IT electrical networks at feeder level, in accordance to installation and products standards. This part is a surge limiter used on IT networks, and installed as close as possible to the medium to low voltage transformer. They protect ungrounded networks from overvoltages that might be caused by transformer breackdown or lighting strikes. This Cardew C is to be installed on a monitored network of 660V AC to 1000V AC when connected between phase and neutral. Or 380V AC to 660V AC if the Cardew C is connected between two phases. It is recommended to monitor the cardew with an insulation fault locator such as the Vigilohm family IFL12. So that an insulation fault due to the cardew can be immediately identified, and its cartridge replaced. The dimensions of this limiter are 160mm in length, and 70mm in diameter, for a product weight of 1 kilogram.