Fuseless Technology - Siemens SINAMICS SL150 Operating Instructions Manual

Description
3.3 Power unit
Figure 3-7
3.3.3.2

Fuseless technology

Components that are to be provided in fuseless design for the converter on the system side
The converter is of fuseless design. In the event of a fault, the overcurrent at the input terminals
is limited using an appropriate transformer design.
In addition, the converter requires matched circuit breakers with a tripping time of 60 ms. The
closed-loop control system triggers the circuit breakers. Each circuit breaker must be equipped
with a fail-safe OFF contact and an undervoltage coil. The circuit breakers are operated via a
back-up combination unit.
Internal current transformers sense the current and evaluate it electronically. The open-loop
and closed-loop control systems prevent the overcurrent from inadmissibly increasing in
regular operation. Prerequisite is that all of the components are appropriately selected and
dimensioned.
34
Line cosϕ as a function of converter control and motor cosϕ
SINAMICS SL150 6SL38600UL432AA0Z
Operating Instructions Rev.201910281433 EXAMPLE