UL 521-1999
UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems Seventh Edition; Reprint with Revisions Through and Including July 20, 2005

Standard No.

UL 521-1999

Release Date

1999

Published By

Underwriters Laboratories (UL)

Status

Be replaced 2004-08

Replace By

UL 521 BULLETIN-2001

Latest

UL 521-2021

Scope

Heat detectors for fire protective signaling systems intended for installation in ordinary indoor and outdoor locations.

UL 521-1999 history

• 2021 UL 521-2021 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems COMMENTS DUE: FEBRUARY 18, 2008
• 2017 UL 521 BULLETIN-2017 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems (COMMENTS DUE: August 2@ 2017)
• 2016 UL 521 BULLETIN-2016 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems (COMMENTS DUE: SEPTEMBER 26@ 2016)
• 1970 UL 521-2016 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems COMMENTS DUE: FEBRUARY 18, 2008
• 2015 UL 521 BULLETIN-2015 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems (COMMENTS DUE: MARCH 16@ 2015)
• 2014 UL 521 BULLETIN-2014 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems (COMMENTS DUE: MAY 23@ 2014)
• 2010 UL 521 BULLETIN-2010 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems
• 2009 UL 521 BULLETIN-2009 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems (COMMENTS DUE: November 02@ 2009)
• 2008 UL 521 BULLETIN-2008 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems (COMMENTS DUE: FEBRUARY 18@ 2008)
• 2001 UL 521 BULLETINS-2001 10/19/2001 (16p)
• 2001 UL 521 BULLETIN-2001 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems
• 1999 UL 521-1999 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems Seventh Edition; Reprint with Revisions Through and Including July 20, 2005
• 1993 UL 521-1993 UL Standard for Safety Heat Detectors for Fire Protective Signaling Systems (Sixth Edition)