Reed ********
******** ******** *** ** *** *** most ****** **** ** ***** *******. Inside ***** ******** ******* ** * reed ******. * **** ****** ******** of *** ** ***** **** ***** blades, ****** *****, ****** * **** glass **** ****** **** ***** ***.
- **** * ******** *** **** *** detecting *** ******* *** ******* ** entranceways
- **** * ******** *** **** *** access ******* ********
- **** * ******** *** **** *** triggering ******** ******* **************
**** *
*** **** ****** ************* *** ***** contacts ** **** *. **** ******* to ******** *****, *** *** ***** will ** ****** ********, ******* *** circuit. **** *** ****** ** *******, the ***** ****** *****, ******* *** circuit. ******* **** *** * **** A ******* ** ******** ****, ** NO.

**** * ******** *** ****** ** let *** ***** ******* ******* * door ** ****** ** **** ** closed. ******** *** **** ****** ** window **** ** **** **** *** mounting *** ****** ** *** ****** or **** ****** *** ****** ** pull **** **** *** **** ****** when *** ****** ** **** ** opened, ******* *** ******* ** **** and *** ***** ** ****** * fault.
**** *
**** * ********, **** ****** ******** Closed (**), **** *** ***** **** touch ***** * ******** ***** ***** them *****. **** *** ****** ** removed, *** ***** ****** **** ********. These *** ** ****** ** ****** control. *** *******, ******* *** ***** door ** * ********* *** ************* unlock *** ******** **** ****** ** the ***** ****.

**** *
**** * ********, **** ***** ** SPDT (****** **** ****** *****) ********, have *** ********. **** * ******** field ** *******, *** ******* ** energized. **** *** ******** ***** ** removed, *** ***** ******* ** *********. This *** ***** * ****** ****** to ***** *** ******** *********. *** example, ******* * **** *** **** an **** ******* ****** ** *** alarm ***** ***** ******* * ****** or ***** ** **** **.

Surface ***** ******** ********
******* ***** ******** ******** *** ******** used ** ***** ** ****** ***** and *******, ********** ** *********. ***** can ****** ** ***** ** *** door ** ****** ***** ** ** replaced ** *** ******. **** ************* include * ****** ** ***, ******** external ******** ** ** **** **** when *** ** ******** *** ****** the **** ** *** **** **** to **** ** **** ** *** point ***** *** **** **** *** quite **** ** **** *** ****.
*** ******* ****** **** ** ******* magnetic ******** ** ******. **** ** *** ******** ** which *** ****** **** ******** *** reed ******. *** *******, * ******* rated *** *.**" (***) **** **** a ****** ******* **** *** ****** is ****** *.**" ** *** *******. Mounting *** ****** *** *** **** the ******* ** * ****** ***** of ***** ******, ** ******* ******* or ********** ********** **** ********** ***** the ****** ** **** **** ******* the ***, ******* *** ***** ***** to ***** *** **** *** ******. Best ********, *********, ** ** ***** the ****** ****** ***** **** ** the ***- */*" (***) ** *** example.
**** ***** ******* ***** ******** ** alarm * ****, ****** ***** ** on *** ****** ****. ******** *** contact ** *** ***** **** ****** the **** ** **** *** **** before *** *** ***** ****** ** cause ** *****, *** ** ** conceivable **** * ************* ******** ***** squeeze ****** ******* ******* *** *** alarm, ** ****** *** ******* ***** their *** ******.

**** ******* ***** ******** *** ***** large, **** * ******* ***** ******* over ********** ***** *********. ***** ****** make ** **** ** *** ** end-of-line (***) ******** *** ****** **** supervision, *** **** *********** ********* *** object ** ********* *******. *** ***** customers, ********* ******* ***** ******** *** be ****. ******* ***** ******** **** built ** **** ***** *** *** relatively ****. **** *********** ** ******** recommended ** ********** *** **** ******** applications, *** ** * *********** *** many ************, ********* ** ****** ******.
Recessed ******** ********
******** ******** ********, ********* ***********-**********, *** * **** ****** *** new ************. ** **** *** ********** hidden **** ****, **** *** ******** used ******** ******** ** ****** *** residential ********. ***** ******** ******** ** new ************ ******** ************ **** *** general ********** *** *** ************* ***** will ** ********** *** ******* *** doors ** **** *** ***** ********* can ** ******* **** *** **** and ******** ** *** **. **** contractors **** ***** *** * ****** to ***** *** ***** ********* ** drill * **** *** *** ******* before ********* *** **** ************. ******* on *** ********** ** ***** * hole *** *** ******* ********* *** chances ** ****************, ******, *** *** wires.
**** ********** * ******** ******* ** a ***** ****, **** ********** ***** the ****** ** ****** ********, ***** will ******** *** ***. **** ****** not ** * ****** ** * tightly ****** ***** ****. ***** * spacer ** ***** *** ******* ** close ** ******** ** *** ****** will ******** *** ******* ** ***** alarms ** *** ******. ********** ****** expect *** ********* *** ** ** about **** ** *** ****** *** rating **** **** ** ***** *****, and ** ****** ********* ***********, ***** spacers ** *** *** ******* ****** about * ******* ** *** ****** gap ******.
** **** ******* ***** ********, ******** contacts ****** ** ******* ** *** strike **** ** *** ****. ******** it ** *** ***** **** ****** the **** ** ** ****** *** far ****** *** *** ******* *** contact *** ****** ****** ******.
** **** ******* ***** ********, ******** contacts *** ********* **** ***** ** EOL *********. ****** ******* ***** ********, however, ****** * ******** ***** *** fact ** **** *********, ** *** connection ** *** **** ** **** inside *** ****. **** ****** * resistor ** * ******** ***** *******, common ******** ** ** ***** *** screw ******** **** ****. ***** * recessed ******* **** * **** ******* of ***** ********* ***** ** **** likely *** *** ******** ** ************* short *** ***** ********, *** **** solution ** ****** **** ********* **** used *** ****** **** ******, *** wooden **** ****** ** ****** ****** sills. *********'* ******** ******** *** * staggered '*' ***** ********, *********** *** need ** **** *** ********.
Wide *** ******** ********
********** *****, *****, ******, *** ****-**** gates ******** **** * *** ** "play", ******** * ******* ****** ** motion ******* *** **** *** ****. Using ******** ******** ** ***** ***** will ********** **** ** ***** ******. Installers ******** *** ******** ******** **** wide **** *** ***** ************. ***** are ********* ****** *** **** ********* than ******** ******** ******** **** *** homes *** *******. **** **** *** contacts *** ***** *** **** ** up ** *" (*.***).
**** ********** ************ ******* *** ******* to ** ********* ******* ********** ****** or *********. **** **** *** ******** are ********* ** ******* ********, **** or ******* ** ******* ****** **** that ****** *** ********* ** **** wire *********** ****** * ***** **** box. ******* ******** *** ******** ***** on *** ****** ** ****-**** *****, as **** *** ********* ***** *** over ** *********.
High ******** ******** ********
** ** ******** ***** ******* ***** the ****** **, **** ******************** ** **** ******* ** ******** a **** ** *** **** ***** and ********* ***** *** ******, ******** this ** ****** **** **** ****. For **** **** ******** ************, ********** can *** * '******' ******, ** which *** **** **** ****** **** a *** ******** ** * ****** magnetic ***** ***** **** ***** ***** it ** ** *** ****** ******** using *** ******** ******. *********** **** a ******** ****** ****** *** ***** magnets, ***** ** **** **** ********* to ********* **** * ****** **** switch.
Plunger ********
******* ******** *** **** ******** **** today **** ** *** ****. ******* of ***** * ******, ***** ******** use * ******* ****** **** ****** the ******* **** ****** **** *** opens *** ******* **** ********. *** spring ****** ***** ******** **** *** eventually, ******* ** *** ******* ***** permanently ***** ****** ** ****, ************ to ***** ******. *******, ******* ******** are *** **** *** ** ***** a **** **** *** ***** **** instead ** *** ****** ****. **** servicing ** *** *****, ********** ********* have ** ****** *** ** ******* the ******* ******* **** * *** one. ****** ******* ******** *** **** reliable *** ****** ******* **** ** the ****, ******** *** ** ******** as *******.
Comments (8)
Paul Curran
In the U.K. Anti mask contacts consist of two reeds (for U.K. Grade 3 and above).
There are two reeds, so if you put a magnetic on the contact or you try to fool the contact with a magnetic it pulls the wrong reed and generates a "mask" condition. For this reason there is a finite gap which needs to be adhered to. This change is signalled via EOL.
Im unsure if the same is true in the US?
I guess this is similar to Magnasphere.
The same is true for flush mount or roller door contacts. Interestingly if the distance on the roller door is too large you must fit one at each end so you can't jack the door up and slide under.
If the door is high security its advised to fit one at the top and one at the bottom on the side ( or other combinations) why? They cut the bottom of the door and open the bottom section leaving the top contact closed! A more common practice is to also fit a PIR or dual technology (microwave and PIR) sensor behind the door.
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Undisclosed Integrator #1
Thank you for this article. While I don't deal with alarm related items often when it does come up it has been a crash course in proper device selection. This assists greatly.
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Daniel Filomena
Just wanted to note - there are Steel Door "push-in" door contacts with larger magnets that last a while longer than wooden door type. I like to make sure metal shavings are not there to collect on magnet as it sits for years.
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Rashid Khan
Hi Ari, will you be doing a Maglock tutorial too? It will be very helpfull.
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