Abstract: A fused tap-off unit for a busbar system is disposed in a length of trunking through which busbars extend. The trunking has a cover inside which fuses are fitted. The fuses interconnect contact blades of which a first set contact the busbars when the cover is closed and a second set contact tap-off terminals loosely secured in insulators. When the cover is opened by pivoting about a hinge axis, the contact blades secured to the cover are withdrawn, whereby the fuses and the tap-off terminals are isolated from the busbars. The busbars also extend through the insulators so that there is no danger of touching live parts when the cover is opened.