3RW2228-1AA15 - Soft starters - SIEMENS

SIKOSTART 3RW22 is suitable for starting motors with protection mode „d“, „p“ or „n“, provided that the intended operating mode is not likely to have a significant influence on the temperature rise.

SIEMENS has received confirmation from the official Physikalisch Technische Bundesanstalt (PTB) laboratory in Braunschweig that, although not expressly stated, there are no reservations about starting explosion-proof motors in protection mode “d” with SIKOSTART. within the framework of the accepted conditions.

The starters are also suitable for starting motors with protection mode “e”, as long as it is not difficult to start. The ramp time must be set to a value which is at most equivalent to the time te of the machine. The PTB test certificate Nr. 3.53-542/96 is available.

3RW22 starters have thermal overload protection. This protection cannot be used to protect connected motors against overloads.

The SIKOSTART is integrated into the motor starter between the cut-off device and the motor (see figure 11). The basic diagram of a classic motor starter remains unchanged and must be sized according to the power of the cage motor used. Any compensation capacitors must only be mounted on the side of the network, upstream of the SIKOSTART, but in no case between the motor and the SIKOSTART.

Electronic starters do not require any special maintenance. ➩ From time to time remove dust deposits on electronic boards and cooling channels using dry compressed air or vacuuming. In the event of heavier soiling, it is advisable to first determine the degree of soiling after a short operating time and then determine the maintenance interval.

In the event of a fault in the power part (broken thyristors), the phase concerned can be easily determined by a resistance measurement. It is unlikely that all the thyristors will be blown at the same time. ➩ Use an ohmmeter to measure the resistance, in the de-energized state, between a network phase and the corresponding motor phase (e.g. L1 - T1). Unbroken thyristors must have a resistance greater than 100 kΩ. For this it is not necessary to disconnect the motor.