Browse & Buy UL Standards

Standard for Heat Detectors for Fire Protective Signaling Systems

UL CSDS Proposal
Standard 521, Edition 7 Edition Date: May 01, 2014
Summary of Topics b0521_7_20140501_sum.html

Subject 521

Bulletin Dated: May 1, 2014

SUMMARY OF TOPICS

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

1. For Preliminary Review Only: Additional Requirements for Servicing and Maintenance Protection

Back to Standard 521, Edition 7

The cost to purchase this Standard varies depending on whether you are ordering a hardcopy, PDF or combination of the two. We also offer two different types of subscriptions: a one year and a three year.

You will be able to choose your purchase options on the following pages.

×
×
×

You have one or more subscriptions that will expire soon.

×