QUESTION:

Which measures for surge suppression have been taken on the function modules 3RA27 and 3RA28?

ANSWER:

All function modules 3RA27 and 3RA28 are off factory equipped with integrated varistor for surge suppression.

For the wye-delta function module, which consists of one basic module and two coupling modules, the following applies:
The basic module comes from factory with integrated varistor.

In the circuit of the basic module for wye-delta starting, a varistor is already factory assembled.

Through parallel connected energizing of the contactor coils by means of plugging the connecting cables the surge suppression of the three subsidiary contactors (line, delta, wye) is established.