Inrush current limiter for three-phase transformers

Description

Information:

• The electronic load relay TSRD can switch on a three-phase transformer or three single-phase transformers under no-load or under load without inrush current.

• The transformers switched by TSRD can thus be set on the primary side with quick-response fuses to their rated current, and are therefore optimally protected against overload and short circuit.

• The TSRD can also be used as a mains switch (without potential separation) if it is activated via the control input.

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

• The TSRD differentiates in its control between three-phase transformers with a primary star or delta connection or three single-phase transformers directly between the three outer conductors or the three outer conductors and the star point.

• The soft switching on of the transformer is done with thyristors, which are bridged out after full switching on by an external bypass relay. This bypass circuit reduces losses in the TSRD. The relay is only required in AC1 class and is not included in the scope of delivery. The TSRD performs an internal contactor pull-in check to indicate a fault in case of relay defects.

• The disconnection also occurs via the thyristors, because first the bypass relay drops out, and only then are the thyristors switched off.

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

 

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Downloads:

Inrush current limiter for three-phase transformers TSRD01 (pdf, 643 KB)

Inrush current limiter for three-phase transformers TSRD02 (pdf, 541 KB)