Wiring contacts

[stevo]

I have hardwired my windows and doors in a new construction home. I have continuity with windows closed and none with windows open. If I have 4 windows in a room and if I want to keep them on one zone, do I wire the contacts together? Should I wire each individually down to the panel?
Even though the sashes on the windows are wired, should I also pir the areas? Glass break the areas? I just realized, if the glass is broken and the windows not opened, the alarm wont sound. If I glass break, should I loop them all togther for as many as I would use on that floor? Should I solder all contact connections or is it ok to use chicklet connectors?

I plan on a Ademco 20p system. Any help would be appreciated

[suemarkp]

With normally closed window contacts, you'll need to wire each window in series so that opening any one breaks the circuit. If you change to normally open contacts, they could be done in parallel. You should be able to handle either configuration if all the wires are run back to a big panel box. This will allow you to fix things should a wire get broken. If you break a wire in a daisy chained configuration from window to window, you may not be able to easily fix a broken wire problem.

Another issue is EOL resistors -- are you using them? If so, be sure to just have one at the end of your link and don't put them on every window segment.

The glass break or not issue is a hard one. It is certainly better to use them, but you need to adjust them correctly. And they are ugly... A motion detector I would do regardless (at least in hallways, perhaps more), but if you have pet issues with them you may end up disabling them (but the better solution would be to buy a better motion detector).

[Tom]

Use a motion. The contacts on the window are really your first defense. They let you know the window is open when you arm. If the glass breaks and they go through there you wouldn't know it, and they know it.

Consider motions a trap and put them so they cover the most likly path of an intruder. Set them up where they detect motion across the field of vision if posible first. They work better that way. get units with pet alleys of that os a concern.

If you can run the wires all the way back to the alam panel do it. Since you have indicated in other posts that you want reliable well done its the way to go. You can isolate and trouble shoot a problem latter and even zone of disired. Its worth the few dollars worth of wire.

If the windows are all on one zone then as posted earlier connect them in series. The wire from one pair connected to one wire of the next until you only have two wires left.

You can put the resister at the panel. Some will say you have better protection at the end of the line line but not nessesarily. would dare say 90 percent or more of the homes are wired with the resister at the panel.

You did right with the Ademco panel it will last a long time and don't forget to run a ground wire to it. Don't overload it with too much power drain on the assesories terminal. If you have oo many motiions and or key pads you should get an additional power supply. There is a load worksheet in the instructions use it.

Good luck,

Tom

[bobm]

>Another issue is EOL resistors -- are you using them? If so, be sure to just have one at the end of your link and don't put them on every window segment.<

Why do you need the EOL resistors, what are their purpose? Would they be used in a simple normally closed circuit?

Thanks Bob

[mdshunk]

End of line resistors are for supervision of normally open contacts. It is to sort out wire breaks and shorts from an actual alarm condition.

[suemarkp]

Can't they work for normally closed too? I thought the panel was looking for a resistance on the sensor loop equal to the EOL value. Whether things are parallel or series, there better be about 2K of resistance. If its lower, something shorted and a trouble alarm sounds (could be someone jumpered a NO contact). If its higher, a wire has been cut or broken.

You can even mix parallel and series contacts on a given loop, but there are some design tradeoffs fo where you place the EOL and why you are using them. Some people put them right at the alarm panel for an NC loop or across the last NO contact in the loop. The NC loop would find shorts in the wiring if the EOL was at the last switch, whereas it won't when at the beginning (panel).

[mdshunk]

Can't they work for normally closed too?
Probably so, but I'm not the alarm expert so I'm only famaliar with their use on NO contacts like system smokes and nurse calls. Mark, if you find a link regarding using EOL resistors on NC contacts, I'd be interested in reading it. I don't do so much alarm work, and when I do it's always the same two or three models. I'd like to expand my horizons a little if you run across any good net reading material on EOL resistors.

[bobm]

>End of line resistors are for supervision of normally open contacts. It is to sort out wire breaks and shorts from an actual alarm condition<

Well I thought I unserstood that but can't see it and maybe I just don't know how to wire and system.

Say I have a small zone with one normally open contact. We would then have a wire leaving the panel and going to the contact and one returning to the panel from the contact. I put my eol in series with the returnwire. I could short those two wires anywhere along the path and I don't see how the panel could tell the defference between a short and the contact closing??

Bob

[Homer]

EOL resistors are wired in series when using NC contacts and in parallel when using NO contacts.

The accepted norm is for fire and smoke alarm devices to be NO and burglar alarm switches and devices to be NC.

Here is a link to an old post (http://www.selfhelpforums.com/showpost.php?p=14957&postcount=7).

Homer

[Unregistered]

Homer,

I will have to read through this.

Propper placement of the EOL resistor must be key. Take a normally closed zone, if the EOL resistor is at the end of the loop where it connects to the panel, I cannot see it doing any good at detecting a wiring fault.

I know its a good idea to home run each device, but if I were wiring two devices in series, I could just send out a single wire and form one loop. Is that correct?

Thanks Bob

[Homer]

Take a normally closed zone, if the EOL resistor is at the end of the loop where it connects to the panel, I cannot see it doing any good at detecting a wiring fault.The EOL resistor should be at the End-Of-Line and not where it connects to the panel. It should be as far away from the panel as it can physically be placed.

I could just send out a single wire and form one loop. Is that correct?Yes, just loop from device to device and make sure that the EOL resistor is at a point that is as close as possible to being at the EOL.

Homer

[mdshunk]

I'm still tickled about the fact that people still write back and fourth with the H.O.M.E.R. automated thread responder just as if it was a real person.

[bobm]

> just as if it was a real person.<

I am not sure I follow? bob

[suemarkp]

Probably so, but I'm not the alarm expert so I'm only famaliar with their use on NO contacts like system smokes and nurse calls. Mark, if you find a link regarding using EOL resistors on NC contacts, I'd be interested in reading it. I don't do so much alarm work, and when I do it's always the same two or three models. I'd like to expand my horizons a little if you run across any good net reading material on EOL resistors.

I haven't seen in depth articles. Its just something to think about, and what you're trying to protect against. Will the alarm see an alarm or a trouble if the wire is cut, shorted, a contact is cut/shorted, etc.

Here is one bone I can throw you -- this link has a nice diagram you can steal that shows you how wire EOL's for NO, NC, and combinations of either:
http://www.installalarm.com/zones2.htm

[mdshunk]

> just as if it was a real person.<

I am not sure I follow? bob
Inside joke, bob. Sorry 'bout that.

[bobm]

Ok, no problem. Bob

[Tom]

The eol is to supervise the circuit. It is mostly used in commercial installations and fire circuits. Some panels can be programmed to work without it.

In the old days you ran two wires to all of your contacts and then back to the panel. The panel used four terminals for the one circuit. These were relay based sysytems. Now take away the two terminals and use a resister you don't have to run wires back to the panel.

Why the supervision. Remember the window foil on the old store fronts. If someone broke the foil or disconnected the window a trouble signal would sound. The same thing would be used with panic buttons, firealrms, and open contacts. I am ony skimimg here. I can go into much detail but you may be bored. I think you get the idea.

Commercial contacs had and can still be had with three terminals. Common, NO, and NC. Alarm on short and or trouble on open circuit.

Did you ever hear the stories of the would be burglar twisting the wires together to shunt (by pass) the alarm durring the day when it was disarmed. The supervision would deter this from happening. A UL commercial installation would require it at the end of the line. This type instal would also detect a ground fault. Sometimes its at the end but inside the panel. Some of the old timers will run a four conductor with two going out and two comming back. The two wires at the panel would be terminated with a resister.

The resister is supposed to go at the end of the line on a circuit. Most panels have six volts at the terminal and three volts with the resister on. Thats one way to test the circuits 9with a VOM) without looking at the kepad.

On a residential application it could go on the panel at the terminal. Make sure its on the common side of the terminal. If its on the positive side you could get a ground and bypass the circuit. Thats why the fire circuit on the these residntial panels have their own terminals.

I have seen hundreds this way. Also, most installers don't leave a note saying where it is and the day you have to trouble shoot you will wast time looking for it. However, I have been on some repaire calls where they reported have the system not working. The trouble being th wire being pinched and shorted bypassing the zone/circuit. Testing your system would have discovered this type of problem early on anyway.

Enough for tonight.

With the resister at the panel you can bypass the circuit anywhere along the line and the control would not know. Something to remember.