With the UFES grounding system operating in <4 milliseconds, the magnitude of the low voltage (LV) fault level becomes a secondary consideration.
Operating speed becomes the critical parameter as final clearing of fault current falls to the upstream/downstream Current Limiting Fuse (CLF).
When the Primary Switching Elements (PSE) activates, a bolted line-to-ground fault is introduced, dramatically reducing the effects of the LV arc fault condition. This line-to-ground fault has the potential to be detected by upstream protection relays and begins tripping breakers mere seconds later. The introduction of CLF in the appropriate location becomes a voltage dip duration device under these conditions. This solution can be accomplished at the low or medium voltage level
and it is type tested according to IEEE C37.20.7
- Greatly increased system and process availability by avoidance of heavy damages inside the switchgear, of the equipment and the direct environment
- Drastic reduction of downtimes and repair costs
- Greatly increased operator safety for switchgears
- Minimization of pressure rise and gases in the faulty compartment and surrounding switchgear building
- Reduction of Voltage Dip duration as seen by upstream devices during fault clearing