Abstract: The present invention provides a signal connection installation including a signal connection device connected to a power fuse holder, in which the power fuse holder holds a power fuse cartridge which carries a supply of mains electrical power in use and in which a conductive component of the signal connection device makes electrical contact with a conductive component of the power fuse cartridge wherein the signal connection device is releasably secured to the fuse holder and the signal connection device includes a signal path interconnecting the mains supply and a communication signal connection, which signal path includes a filter which presents a low impedance to communication signals and a high impedance to mains electricity.