A regular service call for anational chain was 'track problems'
It was always burn outs from the store guys either relamping with the wrong bulbs, or moving heads.
The burn outs were couplings and track, or feed end and track. By the grace of someone, there were no actual fires.
As the service calls & materials dented the corporate pocketbooks, the solution back then was switching the PAR headsout to LV MR-16 with the only bulbs being available being 20 watts. The current limiters would have been good back then.
BTW, the track was comm grade HALO, single and two circ.