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Standard 521, Edition 7

Heat Detectors for Fire Protective Signaling Systems

UL Standard
Standard 521, Edition 7 Edition Date: February 19, 1999 ANSI Approved: March 24, 2021 $402.00-$998.00

Revisions and Related Documents

Revisions
Red Line Std. (16)

Date      
March 24, 2021 Redline Revision
November 18, 2020 Redline Revision
July 01, 2019 Redline Revision
December 08, 2017 Redline Revision
October 12, 2016 Redline Revision
April 09, 2015 Revision
May 19, 2010 Revision
January 29, 2010 Revision
July 20, 2005 Revision
October 22, 2004 Revision
October 03, 2002 Revision
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CSDS
Proposals (16)

CSDS Proposal   

CSDS Proposals

An electronic document associated with a UL Standard for Safety or Outline of Investigation, and issued by UL to propose:

  • A revision of a single or multiple requirement(s).
  • A complete new edition of an existing Standard or Outline.
  • A new Standard or Outline that has not previously been published.

CSDS Proposals provide access to view the proposal and submit comments within UL's Collaborative Standards Development System (CSDS) appropriately.

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January 22, 2021
November 25, 2020
September 11, 2020
June 12, 2020
May 04, 2020
April 19, 2019
October 27, 2017
July 19, 2017
August 26, 2016
January 30, 2015
August 22, 2014
May 01, 2014
October 02, 2009
August 14, 2009
April 16, 2009
January 18, 2008
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UL LLC CRD (0)

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Other Updates (2)

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Bulletin   

Bulletins

These bulletins are not used in CSDS. These are announcement and report type bulletins.

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Summary of Topics (SOT)
July 07, 2010 View
October 19, 2001 N/A
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Referenced Standards (10)

Reverse Referenced Standards (4)

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