REMOTE MOUNTING THE EMERGENCY BALLAST When battery packs are remote mounted, the remote mounting distance can not exceed 1/2 of the distance from ballast to lamp specified by the A.C. ballast manufacturer. For example, if the A.C. ballast manufacturer recommends no more than 25 feet remote distance, then the battery pack should not exceed 12 and 1/2 feet. Typically, the maximum allowable remote mounting distance is 50 feet from the lamp. For I-42 AC Series units, the maximum allowable distance is 10 feet. For I-420 AC Series units, the maximum allowable distance is 6 feet.