Bürkle + Schöck KG

Turn-on current limiter for three-phase transformers TSRD

The TSRD electronic load contactor with its patented soft switch-on procedure can switch one three-phase transformer or three single-phase transformers on idle or under load without inrush current.
switch on.

Thus the transformers switched with TSRD can be set to their rated current on the primary side with fast fuses and are thus optimally protected against overload and short-circuit.

The TSRD can also be used as a mains switch (without potential separation) when operated via the control input.

The TSRD monitors both the voltage level of the three phases and the phase sequence of the connected three-phase mains.

The TSRD distinguishes between three-phase transformers with a star or delta connection on the primary side or 3 single-phase transformers directly between the 3 phase conductors or the 3 phase conductors and the star point.

The transformer is gently switched on by thyristors, which are bridged by an external bypass contactor after full switch-on. This bypass circuit reduces the losses in the TSRD. The contactor is only required in AC1 class and is not included in the scope of delivery. The TSRD carries out an internal contactor tightening check to indicate the fault in the event of contactor faults.

Switching off also takes place via the thyristors, because first the bypass contactor drops out and then the thyristors are switched off.

The TSRD can therefore also switch on unloaded or partially loaded transformers with rated currents of more than 50 A. The TSRD can also switch on unloaded or partially loaded transformers with rated currents of more than 50 A. The TSRD can also switch on unloaded or partially loaded transformers.