Daisy chaing contacts

[RichStevenson]

Hi guys,

Quick question on window contacts. I have a small kitchen cove with three double sash windows. So I'll have 6 window contacts that I want all in the same zone. Is it ok to wire 6 contacts in series? Out of curiosity, what is the limit when wiring in series?

Thanks,

Rich

 

[BraveSirRobbin]

You should not have any trouble with six wired in series as most alarm systems have a generous zone for violated and non-violated indications.

Some things to watch. Make sure they are truly in "series". The best way to test is with a meter on the wire ends that go into the security panel. Remove the wires from the panel and measure them with the meter in "ohms" range. With all contacts closed the reading will probably be somewhere between 2 and 12 ohms (without using EOL, with EOL the reading will be within its range). Then open and close one contact at a time and see if the reading goes to infinity.

Also, if you are using EOL type of zones, make sure you install only ONE resistor in the ENTIRE series loop (probably best located at the contacts furthest from the panel).

 

[RichStevenson]

You should not have any trouble with six wired in series as most alarm systems have a generous zone for violated and non-violated indications.

Some things to watch. Make sure they are truly in "series". The best way to test is with a meter on the wire ends that go into the security panel. Remove the wires from the panel and measure them with the meter in "ohms" range. With all contacts closed the reading will probably be somewhere between 2 and 12 ohms (without using EOL, with EOL the reading will be within its range). Then open and close one contact at a time and see if the reading goes to infinity.

Also, if you are using EOL type of zones, make sure you install only ONE resistor in the ENTIRE series loop (probably best located at the contacts furthest from the panel).

Thanks for the info. I'll make sure to follow your advice on testing. This is my first system I've installed, and I'm pretty sure I'm going with the ELKM1G. That being said are all systems normally closed? I couldn't find the info for ELK and I'm looking at these window contacts
http://www.smarthome.com/7352.html because of their size. The info on the contacts states "Contacts are closed when magnet and sensor are together" so I'm confused if they're NO or NC. But the real question is, can I use them with the ELKM1G?

Thanks again,

Rich

 

[Digger]

You should not have any trouble with six wired in series as most alarm systems have a generous zone for violated and non-violated indications.

Some things to watch. Make sure they are truly in "series". The best way to test is with a meter on the wire ends that go into the security panel. Remove the wires from the panel and measure them with the meter in "ohms" range. With all contacts closed the reading will probably be somewhere between 2 and 12 ohms (without using EOL, with EOL the reading will be within its range). Then open and close one contact at a time and see if the reading goes to infinity.

Also, if you are using EOL type of zones, make sure you install only ONE resistor in the ENTIRE series loop (probably best located at the contacts furthest from the panel).

Thanks for the info. I'll make sure to follow your advice on testing. This is my first system I've installed, and I'm pretty sure I'm going with the ELKM1G. That being said are all systems normally closed? I couldn't find the info for ELK and I'm looking at these window contacts
http://www.smarthome.com/7352.html because of their size. The info on the contacts states "Contacts are closed when magnet and sensor are together" so I'm confused if they're NO or NC. But the real question is, can I use them with the ELKM1G?

Thanks again,

Rich

In the "normal" state (window closed) the contact is closed so it is a normally closed loop.

Something to consider (and not trying to complicate things or confuse you). If you run a quad cable (4 conductors of 22 awg wire) to this window area you could have each of the three windows on a seperate zone if you wanted in the future (one common wire for all 3 zones and one wire for each zone).

Also if you get extra contacts you can set up a second magnet (but no contact) on one or more windows to leave them slightly open but alarmed for venting in the summer. Cheap and easy.

Lots of different options you can do as time and money permit

Have fun!!!

 

[rfdesq]

Since you're going with the ELK M1 don't forget you have 208 zones. I usually wire each window separately and avoid series wiring.

 

[Spanky]

As Digger said "In the "normal" state (window closed) the contact is closed so it is a normally closed loop."


In the industrial switch world, a normally open switch is its contact state with no magnet or outside force applied to it. ie. The contacts are open. In the security trade world, the same switch is called normally closed because the switch is closed when the door or window is closed or in its normal state.

The M1 can use any switch, normally open, or normally closed. Normally closed security switches are wired in series so that if any switch opens, the entire circuit opens. Normally open security switches are wired in parallel so that if any one of the switches close, the entire circuit is closed or shorted.

Burglar security devices are usually normally closed and Fire devices are usually normally open with an end of line supervisory resistor. Commercial fire controls may have a class A fire loop that I will not go into.

 

[gatchel]

Since you're going with the ELK M1 don't forget you have 208 zones. I usually wire each window separately and avoid series wiring.

This really helps when troubleshooting any issues that might pop up. Pull out one device instead of many.

 

[RichStevenson]

Thanks to everyone for the replies. Nice to know I have a place to go when I start instaling. One more question, for now anyway. What's the benefit to motion sensors if I'm installing contacts on all entry points? Is it to cover an intruder breaking the glass and crawling through without opening the window? How should I place them, as in what should they be monitoring? And what which sensors do you recommend that are pet immune.

I know I said one more question but I just thought of a couple more.

Key fobs. Any good ones to use with the Elk?

Are there any other touch screen displays out there besides the one I saw for over $1000?

Thanks,

Rich

 

[rfdesq]

I see CollinR is reading this topic so I'll let him answer some of your questions regarding PIR's. I like the ELK keyfobs and if you can wait for the new ELK TS, I would.

 

[Sacedog]

I see CollinR is reading this topic so I'll let him answer some of your questions regarding PIR's. I like the ELK keyfobs and if you can wait for the new ELK TS, I would.

Is there a place to view the new Elk TS, and see some specs?

 

[rfdesq]

Is there a place to view the new Elk TS, and see some specs?

I don't remember it exactly from the Las Vegas Show, I should have taken a picture, but it looks something like this http://www.iescorp-usa.com/?p=powerline.

 

[CollinR]

Motions, I like the Honeywell/Ademco Dual Technology motions DT7235T but I have not played with every motion available. These are $40 through me and so you should expect to spend somewhere around that.


Install them in places to segment the home, the ends of hallways, shooting across large rooms and put at least one in the master bedroom.

EDIT:
and without a doubt I would series (NC contacts) or parallel (NO contacts) the switches used on those bay windows.

 

[mustangcoupe]

Motions, I like the Honeywell/Ademco Dual Technology motions DT7235T but I have not played with every motion available. These are $40 through me and so you should expect to spend somewhere around that.


Install them in places to segment the home, the ends of hallways, shooting across large rooms and put at least one in the master bedroom.

EDIT:
and without a doubt I would series (NC contacts) or parallel (NO contacts) the switches used on those bay windows.

How does the DT7235T do with cats that like to jump off the fridge right in front of the detector?

 

[GraysonPeddie]

And make sure you don't direct the motion detector toward the windows or put it where direct sunlight or heat from the vent will occur. You want to reduce false alarms.

 

[CollinR]

The effects of a cat will depend on the microwave settings and the mass of the specific cat, that part# is only good up to a point. If a detector exists that can handle that this would be my bet.

No PIR can pass the cat infront of detector test, PIRs only track the number of zones changed. The closer an object becomes the larger a PIR thinks it is.

Since it's not simply a PIR it's not effected by windows or heating vents, but conventional installation rules definately don't hurt and are easy enough to meet.