Change to standard DIN VDE 0100-704

Important changes have been adopted in the standard DIN VDE 0100-704:2018-10 “Requirements for locations, rooms, and installations of a special nature – construction sites.”The standard came into effect on October 1, 2018, with a transition period until May 18, 2021.Note: There is no grandfathering for existing installations beyond this date!

Key changes in the revised version regarding Construction Site Power Distribution Units:

1. Protective device

‍“Three-phase sockets up to and including 63A must be protected by a residual current device (RCD) of Type B in accordance with EN 62423 (VDE 0664-40).” (Section 704.531.3)

Exceptions:

‍Schuko sockets and three-phase sockets ≥ 125A, provided these CEE 125A sockets are not used for loads with frequency converters.

What does this mean in practice?

Many three-phase machines with frequency-controlled drives are used on construction sites – such as cranes, hoists, or pumps.Due to their electronics, these devices can generate DC residual currents exceeding 6 mA, which may render conventional Type A RCDs ineffective.

With the new construction site standard in force, loads up to 63A must be protected by Type B RCDs.️ Important: Different RCD types cannot simply be connected in series – special considerations apply.

Note for event technology: According to DIN VDE 0100-530, Type A RCDs are sufficient for general applications and most devices used. Whether a Type B RCD is required upstream depends on the connected load – e.g., frequency-controlled motors for stages or water curtain pumps.

‍

2. Disconnection device

“Fixed construction site power distributors (ACS) with sockets must include devices for disconnecting the supply that are lockable in the OFF position and operable by untrained persons (BA1). A lockable enclosure alone is not sufficient.” (Section 704.537.101)

What does this mean in practice?

‍A switch must be installed at the input of socket-equipped Construction Site Power Distribution Units. This switch must be operable by laypersons and lockable in the OFF position.