Access Control

Fundamentals - Selecting and Installing Electrical Boxes - Part 1

Electrical boxes come in many shapes, sizes and materials. In many cases, there are several correct options, each with advantages, disadvantages and costs to consider.  This article will cover the most common boxes used at Security Solutions.

Regardless of which box you select, a key factor when installing an electrical box is to set the box or select a mud ring that matches the planned thickness of the wall material AND set it level. 

NO vs NC Basics

Normally Open (NO) and Normally Closed (NC) are simple concepts and yet cause confusion even among experienced technicians. The problem is what is normal?

Door Contacts

A standard wired alarm door contact is, in its uninstalled state, open. However, when installed in a door jam with a magnet on the door, the circuit becomes a normally closed circuit. It is important for an installer to be aware of the differences between a component's NO/NC state and how it will be used in an alarm circuit. 

Routing Cables Through Open Framing

Pre-wiring a job site for low voltage differs from 110/220 electrical from the aspect that we cannot interfere with their system, but they can interfere or affect ours. It is most common for all other trades to have their wiring, plumbing, and HVAC mostly completed before the low volt installer walks on to the job site. This has benefits and negatives for the low volt installer.

Alarm Contacts

Alarm contacts are sensors which use a magnet to close a circuit. When the magnet moves away from the contact, the circuit opens. The distance the magnet moves before the circuit opens is called the "Sensor Gap" . The gap is affected by the distance between the contact and magnet, orientation of the magnets poles  to the contacts internal reed switch, the material which the contact and magnet are mounted too and size of the magnet.