Enclosure helps meet NFPA regulations

Edited by the Engineeringtalk editorial team Oct 26, 2006

Hoffman has released the innovative Sequestr external disconnect enclosure to help manufacturers comply with National Fire Protection Agency regulations.

Hoffman has released the innovative Sequestr external disconnect enclosure to help manufacturers comply with National Fire Protection Agency (NFPA) regulations.

Sequestr is designed to isolate the fused disconnect switch or circuit breaker from the main control panel while maintaining the door interlocking requirements of NFPA79, IEC60204 and SAE HS1738, the principal electrical standards for industrial machinery.

With traditional disconnect enclosures, even when power is turned off, live power is still present on the line side of the switch, requiring anyone accessing the inside of the enclosure to wear the personal protective equipment (PPE) appropriate for the amount of incident energy present.

Wearing bulky PPE while servicing electrical equipment decreases productivity by increasing service time.

By isolating the switch in the Sequestr external disconnect enclosure, live power is no longer present in the main control enclosure when power is turned off at the switch.

This allows technicians to work inside the main enclosure without the need for PPE (after verifying that power on the load side of the switch is not present).

When the main power is on at the disconnect, Sequestr's own door cannot be opened, and its interlock prevents the main control enclosure door from being opened.

This interlocking feature distinguishes the Sequestr external disconnect enclosure from a traditional safety switch and maintains compliance with industrial machinery standards.

The Sequestr external disconnect enclosure is available in two offerings - as a complete package for OEMs building new systems and as a retrofit kit for upgrading existing installations.

"Our OEM customers are looking for ways to offer inherently safer systems", said Betty Jackson, Senior Product Manager.

"And end users with control enclosures already installed are looking for ways to promote plant safety as part of the NFPA70E directive".

Sequestr meets the following industry standards: Underwriter Laboratories (UL) 508A, UL508, UL Type 12, National Electrical Manufacturers Association (NEMA)/EEMAC Type 12, JIC Standards EGP-1-1967 and EMP-1-1967, Canadian Standards Association (CSA) C22.2 No 94 Type 12 and IEC60529 IP55.