The new version of DIN VDE 0100-704 – construction of low voltage installations – requirements for work premises, rooms and special types of installations – construction sites – was published in October 2018.
The updated standard stipulates that three-phase sockets up to 63 A must always be protected using AC-DC sensitive residual current devices. In other words, the Type B is now mandatory in building-site distribution boards.
This is not actually completely new, as DIN VDE 0100-530 already stipulates that Type B residual current devices must be used with, for example, frequency-controlled equipment that may give rise to smooth DC residual currents in the event of a fault. These are part of everyday life on construction sites, as they include cranes and equipment with power-controlled drives such as masonry saws, wire saws, pumps, fans, sand sieves, compressors, vibrators, etc. There is a long transition period, but equipping building-site distribution boards to comply with legal standards is and remains a managerial decision and is the responsibility of the builder or operator. This decision is made somewhat easier thanks to an incentive from BG Bau. It will provide a subsidy of up to 300 euros for upgrades to building-site distribution boards to ensure they include AC-DC sensitive residual current circuit-breakers. There is more information and an application form on the BG Bau website.