This paper presents the radiation spectrum of the are plasma in a simple experimental model of a high voltage, high breaking capacity (HBC) fuse. A crowbar circuit is applied to force the arcing current to zero. A 62.5 mu m diameter multi-mode silica fibre is used as a light-pipe to carry the plasma radiation from within the are space of the experimental fuse to the spectrograph. Temporal resolution is obtained by a specially designed opto-electronic circuit that moves the fibre along the entrance slit to the spectrograph. Si II, Si III, Ag I and O LI lines have been detected in the plasma. It has been observed that only Si II lines last for the whole time for which the are was scanned. The disappearance of the O II and Si III lines suggest that the plasma temperature drops significantly towards the later stages of arcing.