![]() ![]() ![]() When the resistance drops to nothing (a short), they activate to preserve the loop integrity on their “in” side. As long as there is resistance on the circuit, they’re “happy”. Most isolators are “dumb” devices comprising a simple relay in a short sensing circuit on their “out” terminals. Data Communication Loop (DCL) Isolators – some manufacturers call them Signal Line Circuit (SLC) Isolators.In North America, there are four distinct “families” of short circuit isolators. An isolator is a device that is designed to limit the extent a circuit is compromised by a single “short” fault. What is an isolator, and how does it work? Let’s begin by actually answering these two questions. We’re going to focus on the changes currently adopted by the Canadian Standard for Installation of Fire Alarm Systems (CAN/ULC-S524) as well as what’s “in the pipe” in the way of amendments. In this article, we’re going to discuss “isolators” and more specifically, the correct wiring methods for the various types of circuits you’re going to encounter, as well as the testing that must be performed, both at the system’s commissioning/Verification and on an annual basis. Unfortunately, each new advance exposes some vulnerability that must also be addressed. In the last twenty (or so) years, I’ve been privileged to have been able to watch the tremendous advances in technology that continues to inspire several manufacturers around the world to explore new developments in electronic life safety systems. ISOLATOR INSTALLATION, INSPECTION, AND SERVICE! ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |