When do you need an end of line resistor in a burglar alarm?

he purpose of EOLR's is to allow the control panel to supervise the field wiring for open or short circuit conditions. How the alarm responds to each depends on the panel as well as system zone programming, but generally speaking, an alarm views an open circuit as a fault or alarm condition, and a short circuit as a trouble or alarm condition (if armed). The purpose of EOLR's is to allow the panel to differentiate between the two conditions by looking for a known resistance.
EOLR's should be installed at the last device on the loop, electrically speaking, and not inside the control, unless special conditions are met. The benefits of EOLR's on protective zones with all concealed wiring is commonly argued by professional installers, as well as EOLR's installed inside the control unit, negating their effetiveness, as well as disabling the EOLR feature and using NC (normally closed) loops for zone definitions. The use of EOLR's is recommended and is particularly important when the field wiring is subject to damage or compromise.
A fire EOLR should always be installed at the last device and never inside the control or across the zone defined as fire, as this is an inherent safety issue.
Some equipment supports Double End of Line Resistors (DEOLR) to further differentiate between conditions that may exist on the loop.

I've linked my source.
4 people found this useful
Thanks for the feedback!

How do you replace burglar alarm battery?

  If you're relatively handy, this is not a difficult task. The hardest part will be opening the enclosure the control panel sits in. A typical residential burglar alarm (MORE)

Input and output devices in a burglar alarm?

A security system, also known as a "burglar alarm," contains two  primary device categories. Sensors are the system inputs by serving  as its eyes, ears and even noses. Thes (MORE)

The Smoky Eye: A Step by Step Guide

It has been said that 'the eyes are the windows to your soul', so why not make them look their best. The smoky eye is versatile in that, it creates just as much of an impact d (MORE)

Four Interesting Things to See and Do in Sorrento

Whether you're a history buff interested in visiting Roman ruins, an artist wishing to explore the Greek and Italian architecture, or if you just want to relax high above the (MORE)

Do burglar alarms have infra red lasers?

There are multiple types of alarm systems and sensors available for them. While low-powered lasers could be used, they are not usually. More common is what is called a PIR, (MORE)
In Uncategorized

Why put a burglar alarm sensor in a bedroom?

You probably wouldn't want to put a motion sensor in the bedroom, unless you were only going to activate it when no one is home. You definitely do want sensors on the bedroom (MORE)

Make Your Own Dry Erase Calendar

Paper calendars are expensive and boring. They are also easy to misplace. This do it yourself calendar works as a one-and-done since it can be changed for each month of the ye (MORE)