HD4/R are used in secondary MV distribution and in MV/LV transformer substations. They are available in fixed version with right-hand side operating mechanism. Circuit-breakers with rated voltage up to 24 kV can be fitted with current sensors and PR521 overcurrent release and can be used in unmanned substations without auxiliary power supply.
| Rating |  |
| Rated voltage (kV) | 12 ... 36 |
| Rated current (A) | 630 ... 1250 |
| Breaking capacity (kA) | 12,5 ... 25 |