To upgrade a electrical equipment by using products suitable for the particular application.
If it is considered as proper when the standard MCCB/ELCB is not chosen to use in a special characteristic of the load, the special breaker is needed.
In case of depending on a kind and a characteristic of the load, MCCBs or ELCBs have only Instantaneous characteristic are used.
As a result of making a Isolation switch (DSN) by omitting the overcurrent tripping device of a MCCB, it is used as a switching device having high operating capacities.