Hoffman Sequestr® External Disconnect Enclosures

Hoffman Sequestr External Disconnect Enclosures

Maintaining NFPA 70E compliance through conventional methods can be costly in terms of resources and efficiency. Instead, choose Sequestr® external disconnect enclosures from Hoffman and Graybar – they reduce the risks of arc flash explosions by providing convenient access to enclosed components without opening the enclosure door.

A traditional disconnect switch inside the main enclosure feeds live power upstream to the disconnect switch on the panel, running the risk of arc flash. The smaller Sequestr power isolation enclosure is interlocked to the main enclosure to isolate — or sequester — the fused disconnect switch or circuit breaker from the main control panel. Attached to the side of the main control enclosure, Sequestr houses only the disconnect switch or circuit breaker. Power passes from the disconnect enclosure to the main enclosure via a terminal block mounted on the shared enclosure walls. As a result, when the disconnect switch is off, no power feeds into the main control enclosure – the live-line side of the disconnect switch is isolated in the Sequestr Enclosure. You and your technicians can work inside the main enclosure without the need for personal protection equipment.

In addition to housing the external disconnect, when the disconnect switch is powered on, Sequestr interlocks the doors of the main control cabinet, allowing users to comply with the disconnect door interlocking requirements of UL 508A, NFPA79, IEC 60204 and HS 1738, the most common electrical standards for industrial machinery.

Your Graybar representative has complete information about eliminating arc flash risk with Sequestr by Hoffman.


[PDF] Hoffman Arc Flash Safety Systems Brochure