1s26-m.pdf
Arc fault protection is a technique for the fast clearance of arcing faults on busbars and within metal-clad switchgear and cable boxes. The arc is detected by an optical sensor, with the signal fed to a device that also monitors load current. A trip can be achieved in under 10 ms using arc detection alone, or within 15 ms with the integrated instantaneous overcurrent check, far faster than traditional IDMT relays. The 1S26 Arc Fault relay suits new or existing medium voltage busbar systems with up to two incoming lines, and can also protect outgoing feeders.