Alarm Contacts Tutorial

Author: Ari Erenthal, Published on Mar 07, 2017

Contacts are the devices that tell an alarm panel when an entryway is open or closed. The act of opening or closing an entryway, such as a door or window, causes a physical change in the contact. This in turn changes the state of the circuit to which it is connected.

In this note, we will examine and compare:

  • Reed switches - Form A vs B vs C
  • Surface mount magnetic contacts
  • Recessed magnetic contacts
  • Wide gap magnetic contacts
  • High security magnetic contacts
  • Plunger contacts

******** *** *** ******* **** **** ** ***** ***** **** an ******** ** **** ** ******. *** *** ** ******* or ******* ** ********, **** ** * **** ** ******, causes * ******** ****** ** *** *******. **** ** **** changes *** ***** ** *** ******* ** ***** ** ** connected.

** **** ****, ** **** ******* *** *******:

  • **** ******** - **** * ** * ** *
  • ******* ***** ******** ********
  • ******** ******** ********
  • **** *** ******** ********
  • **** ******** ******** ********
  • ******* ********

[***************]

Reed ********

******** ******** *** ** *** *** **** ****** **** ** alarm *******. ****** ***** ******** ******* ** * **** ******. A **** ****** ******** ** *** ** ***** **** ***** blades, ****** *****, ****** * **** ***** **** ****** **** inert ***.

  • **** * ******** *** **** *** ********* *** ******* *** closing ** ************
  • **** * ******** *** **** *** ****** ******* ********
  • **** * ******** *** **** *** ********** ******** ******* **************

**** *

*** **** ****** ************* *** ***** ******** ** **** *. When ******* ** ******** *****, *** *** ***** **** ** pulled ********, ******* *** *******. **** *** ****** ** *******, the ***** ****** *****, ******* *** *******. ******* **** *** a **** * ******* ** ******** ****, ** **.

**** * ******** *** ****** ** *** *** ***** ******* whether * **** ** ****** ** **** ** ******. ******** the **** ****** ** ****** **** ** **** **** *** mounting *** ****** ** *** ****** ** **** ****** *** magnet ** **** **** **** *** **** ****** **** *** window ** **** ** ******, ******* *** ******* ** **** and *** ***** ** ****** * *****.

**** *

**** * ********, **** ****** ******** ****** (**), **** *** reeds **** ***** ***** * ******** ***** ***** **** *****. When *** ****** ** *******, *** ***** ****** **** ********. These *** ** ****** ** ****** *******. *** *******, ******* the ***** **** ** * ********* *** ************* ****** *** electric **** ****** ** *** ***** ****.

**** *

**** * ********, **** ***** ** **** (****** **** ****** throw) ********, **** *** ********. **** * ******** ***** ** present, *** ******* ** *********. **** *** ******** ***** ** removed, *** ***** ******* ** *********. **** *** ***** * single ****** ** ***** *** ******** *********. *** *******, ******* a **** *** **** ** **** ******* ****** ** *** alarm ***** ***** ******* * ****** ** ***** ** **** on.

Surface ***** ******** ********

******* ***** ******** ******** *** ******** **** ** ***** ** wooden ***** *** *******, ********** ** *********. ***** *** ****** be ***** ** *** **** ** ****** ***** ** ** replaced ** *** ******. **** ************* ******* * ****** ** two, ******** ******** ******** ** ** **** **** **** *** or ******** *** ****** *** **** ** *** **** **** to **** ** **** ** *** ***** ***** *** **** does *** ***** **** ** **** *** ****.

*** ******* ****** **** ** ******* ******** ******** ** ******. **** ** *** ******** ** ***** *** ****** **** activate *** **** ******. *** *******, * ******* ***** *** 1.25" (***) **** **** * ****** ******* **** *** ****** is ****** *.**" ** *** *******. ******** *** ****** *** far **** *** ******* ** * ****** ***** ** ***** alarms, ** ******* ******* ** ********** ********** **** ********** ***** the ****** ** **** **** ******* *** ***, ******* *** alarm ***** ** ***** *** **** *** ******. **** ********, therefore, ** ** ***** *** ****** ****** ***** **** ** the ***- */*" (***) ** *** *******.

**** ***** ******* ***** ******** ** ***** * ****, ****** mount ** ** *** ****** ****. ******** *** ******* ** the ***** **** ****** *** **** ** **** *** **** before *** *** ***** ****** ** ***** ** *****, *** it ** *********** **** * ************* ******** ***** ******* ****** without ******* *** *** *****, ** ****** *** ******* ***** their *** ******.

**** ******* ***** ******** *** ***** *****, **** * ******* cover ******* **** ********** ***** *********. ***** ****** **** ** easy ** *** ** ***-**-**** (***) ******** *** ****** **** supervision, *** **** *********** ********* *** ****** ** ********* *******. For ***** *********, ********* ******* ***** ******** *** ** ****. Surface ***** ******** **** ***** ** **** ***** *** *** relatively ****. **** *********** ** ******** *********** ** ********** *** high ******** ************, *** ** * *********** *** **** ************, including ** ****** ******.

Recessed ******** ********

******** ******** ********, ********* ***********-**********, *** * **** ****** *** *** ************. ** **** are ********** ****** **** ****, **** *** ******** **** ******** possible ** ****** *** *********** ********. ***** ******** ******** ** new ************ ******** ************ **** *** ******* ********** *** *** subcontractor ***** **** ** ********** *** ******* *** ***** ** that *** ***** ********* *** ** ******* **** *** **** and ******** ** *** **. **** *********** **** ***** *** a ****** ** ***** *** ***** ********* ** ***** * hole *** *** ******* ****** ********* *** **** ************. ******* on *** ********** ** ***** * **** *** *** ******* increases *** ******* ** ****************, ******, *** *** *****.

**** ********** * ******** ******* ** * ***** ****, **** eventually ***** *** ****** ** ****** ********, ***** **** ******** the ***. **** ****** *** ** * ****** ** * tightly ****** ***** ****. ***** * ****** ** ***** *** contact ** ***** ** ******** ** *** ****** **** ******** the ******* ** ***** ****** ** *** ******. ********** ****** expect *** ********* *** ** ** ***** **** ** *** stated *** ****** **** **** ** ***** *****, *** ** should ********* ***********, ***** ******* ** *** *** ******* ****** about * ******* ** *** ****** *** ******.

** **** ******* ***** ********, ******** ******** ****** ** ******* on *** ****** **** ** *** ****. ******** ** ** the ***** **** ****** *** **** ** ** ****** *** far ****** *** *** ******* *** ******* *** ****** ****** enough.

** **** ******* ***** ********, ******** ******** *** ********* **** built ** *** *********. ****** ******* ***** ********, *******, ****** a ******** ***** *** **** ** **** *********, ** *** connection ** *** **** ** **** ****** *** ****. **** adding * ******** ** * ******** ***** *******, ****** ******** is ** ***** *** ***** ******** **** ****. ***** * recessed ******* **** * **** ******* ** ***** ********* ***** it **** ****** *** *** ******** ** ************* ***** *** screw ********, *** **** ******** ** ****** **** ********* **** used *** ****** **** ******, *** ****** **** ****** ** wooden ****** *****. *********'* ******** ******** *** * ********* '*' screw ********, *********** *** **** ** **** *** ********.

Wide *** ******** ********

********** *****, *****, ******, *** ****-**** ***** ******** **** * bit ** "****", ******** * ******* ****** ** ****** ******* the **** *** ****. ***** ******** ******** ** ***** ***** will ********** **** ** ***** ******. ********** ******** *** ******** contacts **** **** **** *** ***** ************. ***** *** ********* larger *** **** ********* **** ******** ******** ******** **** *** homes *** *******. **** **** *** ******** *** ***** *** gaps ** ** ** *" (*.***).

**** ********** ************ ******* *** ******* ** ** ********* ******* accidental ****** ** *********. **** **** *** ******** *** ********* in ******* ********, **** ** ******* ** ******* ****** **** that ****** *** ********* ** **** **** *********** ****** * metal **** ***. ******* ******** *** ******** ***** ** *** bottom ** ****-**** *****, ** **** *** ********* ***** *** over ** *********.

High ******** ******** ********

** ** ******** ***** ******* ***** *** ****** **, **** can***************** ** **** ******* ** ******** * **** ** *** door ***** *** ********* ***** *** ******, ******** **** ** easier **** **** ****. *** **** **** ******** ************, ********** can *** * '******' ******, ** ***** *** **** **** spring **** * *** ******** ** * ****** ******** ***** comes **** ***** ***** ** ** ** *** ****** ******** using *** ******** ******. *********** **** * ******** ****** ****** for ***** *******, ***** ** **** **** ********* ** ********* than * ****** **** ******.

Plunger ********

******* ******** *** **** ******** **** ***** **** ** *** past. ******* ** ***** * ******, ***** ******** *** * plastic ****** **** ****** *** ******* **** ****** **** *** opens *** ******* **** ********. *** ****** ****** ***** ******** wear *** **********, ******* ** *** ******* ***** *********** ***** closed ** ****, ************ ** ***** ******. *******, ******* ******** are *** **** *** ** ***** * **** **** *** hinge **** ******* ** *** ****** ****. **** ********* ** old *****, ********** ********* **** ** ****** *** ** ******* the ******* ******* **** * *** ***. ****** ******* ******** are **** ******** *** ****** ******* **** ** *** ****, although *** ** ******** ** *******.

Comments (8)

** *** *.*. **** **** ******** ******* ** *** ***** (for *.*. ***** * *** *****).

***** *** *** *****, ** ** *** *** * ******** on *** ******* ** *** *** ** **** *** ******* with * ******** ** ***** *** ***** **** *** ********* a "****" *********. *** **** ****** ***** ** * ****** gap ***** ***** ** ** ******* **. **** ****** ** signalled *** ***.

** ****** ** *** **** ** **** ** *** **?

* ***** **** ** ******* ** ***********.

*** **** ** **** *** ***** ***** ** ****** **** contacts. ************* ** *** ******** ** *** ****** **** ** too ***** *** **** *** *** ** **** *** ** you ***'* **** *** **** ** *** ***** *****.

** *** **** ** **** ******** *** ******* ** *** one ** *** *** *** *** ** *** ****** ** the **** ( ** ***** ************) ***? **** *** *** bottom ** *** **** *** **** *** ****** ******* ******* the *** ******* ******! * **** ****** ******** ** ** also *** * *** ** **** ********** (********* *** ***) sensor ****** *** ****.

**** *** **** **** ****, ** **** "******". **** **** description, ** ***** **** **'** ******* ***** *** **** *****. Magnasphere ** * ********** ************** **** **** * **** ******* which ******* *** ******* ** ********* *** ******.

** *** **** ** **** ******** *** ******* ** *** one ** *** *** *** *** ** *** ****** ** the **** ( ** ***** ************) ***? **** *** *** bottom ** *** **** *** **** *** ****** ******* ******* the *** ******* ******!

**** ****, ***, ********** *** ****-**** *****. ****'* *** * prefer ****** ******* ******** ** **** ********.

*** * ***** **'* *** *** *** **** **** / anti ****. **** **'* * ********* *****- *** ********* ********* demand ** *** ********* *** ****** *** ******** **********. :)

***** *** *** **** *******. ***** * ***'* **** **** alarm ******* ***** ***** **** ** **** **** ** ** has **** * ***** ****** ** ****** ****** *********. **** assists *******.

**** ****** ** **** - ***** *** ***** **** "****-**" door ******** **** ****** ******* **** **** * ***** ****** than ****** **** ****. * **** ** **** **** ***** shavings *** *** ***** ** ******* ** ****** ** ** sits *** *****.

** ***, **** *** ** ***** * ******* ******** ***? It **** ** **** ********.

***** ******:

** **** ******* ********* ****** ** ********, **:

** ****, ** **** ***** * *** ** ******* *******! A **** ***** ** ***** ** *** **** ****** ******* Book,***** ** ********* ** ******** *** ****.

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