The ATB-high-voltage three-phase motors are explosion-proof in the explosion protection type “flameproof enclosure“, in accordance with DIN EN 50 014, VDE 0170/0171 for the Groups IIC and IIB and the temperature classes T3 to T6.
Depending on the design, round wire random-wound windings or conventional form-wound coils are used. The thermal application corresponds to class B temperature rise.

The connection of the motors is implemented either via “increased safety” or “flameproof enclosure” terminal boxes designed for rated voltage up to 6.6 kV. The terminal box is arranged in top-mounting as standard arrangement. Side-mounting versions are possible. The boxes can be rotated at 4 x 90° interval, this allows connection from all directions. This is possible without rotating the connecting terminals. On request, the neutral (or Star) -point can be placed in a second terminal box. The main and neutral-point boxes are then arranged at intermediate connections enclosed flameproof, i.e. mounted on the motor support. By replacing the terminals between the two boxes, there is a possibility of dual voltage-selection capability in this case.

All high-voltage motors are equipped with an insulated bearing on the non-drive end as standard version.