https://afr.mitsubishielectric.com/fa/en/products/lv_distri/lvc-breakers/spcb/isolation-switches-dsn/dsn400-sw-3p-400a.html
DSN400-SW 3P 400A
On creating an isolation switch (DSN) by omitting the overcurrent tripping device of a MCCB, it can be used as a switching device with high operating capacity.
sw