The supply of energy serves the electrical supply of fire detectors, release equipment, hold-open devices and additional equipment. In certain cases safety devices (monitoring of the closing area e.g. by means of light barriers, contact bar) for compliance with accident prevention regulations, requirements of the principles for the approval of track-bound conveyor systems or others are required. For such a situation the power supply needs to be equipped with a second energy source for bridging power breakdowns by means of maintenance-free batteries for alarm systems according to reference source VdS-2140. The supply of energy needs to be in conformity with valid standards. Notwithstanding energy supply in connection with personal safety devices must be able to maintain normal operation for at minimum 4 hours in case of power breakdown. In case of power breakdown the conveyor system shutter may be released for closing as soon as there are no people or objects e.g. material to be conveyed in the closing area. At the time of closing the still available battery capacity shall be sufficient to guarantee the operation of the safety equipment for further 30 minutes.
For hold-open devices as part of track-bound conveyor systems the power supply must maintain normal operation in case of power breakdown for only 1 hour.