The block BDC is executed on the basis of the amplified (strengthened) information-warning mark. The rack is executed of atmosphere firm, not combustible composite plastic. BDC (one – contour or two-contour) is placed in the top part of the rack. In a zone of installation BDC, on the rack are executed rain-repulsive ventilating lattices. On an internal part of the rack is fixed metal thermal-repulsive screen, in addition, protecting the rack from overheating.. The block BDC is closed by a cover with the internal lock or two-element bolt fastening with an internal deepening on a turn-key basis. On a cover the electrical basic circuit BDC is put. All elements BDC are executed on an internal part of an assembly layer, that in addition hides details of the block in case of the non-authorized opening. The contact removals, necessary for switching and measurements, are removed on a face sheet and are accordingly marked. The base variant BDC is completed by a cable VVG-2х6. An output of cable from the rack – 5m. The change of length, trade mark of cable, resistance of a set of resistors and another is possible by agreement with the customer. The execution of BDC with smooth regulation of resistance of resistors is offered