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Standard for Heat Detectors for Fire Protective Signaling Systems

UL CSDS Proposal
Standard 521, Edition 7 Edition Date: July 19, 2017
Summary of Topics b0521_7_20170719_sum.html

Subject 521

Bulletin Dated: July 19, 2017


The following changes in requirements to the Standard for Safety for Heat Detectors for Fire Protective Signaling Systems, UL 521, are being proposed for preliminary review and comment only:

1. For Preliminary Review Only: Temperature Profile Graph Modification

Back to Standard 521, Edition 7

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