Gate Sensor?

I'd use an overhead door contact, for the durability and the extra "gap" you'll need for a gate.

How should I get from the gate into the post? Some sort of flexible look I would think, but not sure where to find it.

TIA

A picture would help.

Generally you can fish the wire through the insides of the gate's tubing. It's best to use "armored" cable for coming out of the tubes, and as a flexible conduit for transitions to boxes, etc... You can buy the small empty cable armor at ADI, and just run a 22/4 thru it. (It's the same size that comes with the OH contacts. Don't know the part # off hand).

Or you can use PVC conduit, and boxes mounted right to the gate, but it won't look as pretty.

I don't think a mag/contact type switch is going to work for you. It would be very easy to circumvent. I'd suggest going with a "pull-apart" connector you can supervise. On similar installations we used automotive trailer connectors (they're weather-proof and very robust). Armoured cable from the two halves of the pull-apart to a couple of outdoor single gang boxes mounted on each gate (you can buy empty outdoor flex to run the wires in). Contact the covers to prevent tampering and mount an end-of-line resistor in the one box. On the other gate you'll have to run some flex down the top (or bottom) to the post to another weather-proof box on the post (leave enough slack to be able to open and close the gate without putting any strain on the flex). You'll have to secure the flex to the gate and the post. Then it's up to you how you want to run it to the side of the main building and interface it with the buildings security system.

GE Security makes a bracket to mount their wide gap contacts to a chain link fence or similar gate. It's called a 1963-L. They run about $9 or $10 retail; less if you have an ADI account.

"Steve" wrote in news:OUFLm.134774$la3.122929@attbi_s22:

How bout this:

Part Number 8450-2 Gate Mounting Kit Consists of:

1 S4402-A SPDT Switch 1 M-4400 Magnet 2 S-202 Brackets 4 #6-32 x 5/16 Zinc Hex Nuts 4 #6 External Lock Washers 4 #6-32 x 3/4 Phillips Machine Screws 2 #8 x 1 Self Tap Combo Panhead Type A Screws

GRI contact for gates.

ones?

There is one complaint I've had regarding these gate contacts... changing seasons is not kind to them.

Every six months or so we get calls from whereever we have these installed to come out and fix them. Turns out that the gates and fences move so much that the contacts won't line up to the magnets anymore. Eventually the fence post has dozens of extra holes in it.

Also, do not use the supplied bolts to secure anything to anything. They will break halfway through installation.

The pull apart switch may be a good solution for you...

I haven't installed one of these yet, but have built something similar with good success. We've had one floating around in the office for at least the past five years (the 4704-A by the looks of it), mixed in with a random assortment of odd contacts and switches. Looking at how it's designed though, it looks like it would work very well. In case someone's thinking of just unscrewing it off the post, it has that covered already. Remove the four obvious screws and you'll find that you need to disconnect the switch in order to remove the hidden screw. Too late though, the zone is already open.

- Chris

CH®IS wrote in news:nUKLm.52035$Db2.33041@edtnps83:

Amen to that

I'm not the OP, but you might bet right, especially if it is a walk thru gate.

I have used unistrut channel to mount the contacts. If adjustments are necessary later, you can usually move the channel without re drilling. It also gives you a more stable mounting surface for the contact and magnet, and facillitates allignment.

I have only one objection to pull apart sensors. You have to remember to reconnect them every time you use the gate. Homeowners may be good at remembering but the mailman, newspaper carrier, UPS drivers, etc., are not likely to do it. That means every time someone other than a family member leaves the property it's necessary to go out and fix the thing again. My guess is that after a while they'll stop using it and just bypass the zone.

The problem with gates becoming misaligned is true with older fences. Newer ones may hold up better for some years. I've used GE Security's wide gap sensors for gates on a number of sites with fairly good results. The sensors have a 3" gap. During installation I try to get them no more than 1/2" apart. That way if they move out an inch or two over time the zone is still good.

I used GE's overhead door contacts for the same reason. In Connecticut winters there were frequent snow storms. When snow and ice would build up the doors didn't always close completely. By placing the magnet on top of the door where it had to pass by the contact I got almost 5-inches of play before the sensor would trip. With a gate contact you don't have a way to extend the coverage like that but the 3" gap is often enough.

Finally, if you use a clamp method to hold the magnet to the gate, you can avoid drilling lots of holes. If the client is in the least bit handy, show him how to adjust the set screws once a year. Otherwise make it part of your annual inspection and service visit. Some things just always need attention. :(

This is a gate to an RV pad. I don't think the mailman, newspaper carrier, or the UPS driver will be using it. Particularly if it's got a sign on it that says it's "alarmed". The best suggestion was the use of a camera and DVR combination. You can set up the camera to switch the alarm output when movement of the gate is detected. Then you'll have an image of the perp for the cops to see as well.

Thanks. I missed that.

Probably not.

That depends on what is being done once the zone is tripped. If the output is wired to a burglar alarm zone, I'd hesitatate to rely exclusively on video motion. Too many false alarms. OTOH, if the video is going to be remotely monitored, that would be fine. Otherwise, I'd prefer there be at least one other sensor ANDed to the output.

Nice, as long as you're doing something "else" to limit false alarms. Your thoughts?

ing to be remotely

In my case it was a fenced storage yard for a company. Locked at night, six days a week and all day Sundays and holidays. An occasional cat or other animal would trip it but with remote viewing, it could be determined what had tripped it. I hooked a speaker and a Visonic audio board with a "You have been detected" message and turned on lights.to the alarm output of the DVR.

The company would pre-load their delivery trucks for next day deliveries. With ( illegal) barbed wire on the tops of the fence, the crooks had busted the chain on the gate and emptied the trucks. The client didn't want to go for the CCTV as first recommended because of the cost but when the gate contacts became too much of a maintinence problem and failed in the closed condition once (which went undetected for who knows how long)

They apparently made more attempts which we believed to have been considered false alarms at the time and apparently after discovering that the gate was protected, they cut the barbed wire, jumped the fence and raided the trucks.

Only one more (failed) attempt was made after the cameras were installed.

So the crooks learned and the client learned the hard way.

That's the key. You're verifying before dispatch.

After a few false alarms and a robbery or two, the cost of a CCTV system starts to sound very reasonable, no?

As long as they're paying you for the tuition... school is in.

Very true. It comes down to a matter of getting them to get their staff into the habit of using them. Other people aren't a concern, these are always gates that are only closed when the business is closed... and are locked.

Do you have a link for these contacts? It's been awhile since I've had to play with one of these gate contacts but I don't believe they get close to

3" of a reliable gap.

Connecticut winters? I spent a couple minutes on google trying to figure out if those exist. I'm quite sure they don't.

Speaking of winters though, the other problem we have is with beam systems. The posts are always moving around with the weather. Turns out the best way to protect something is to remove the fence and build a wall.

- Chris

There are several GE contacts you can use. The 2315AL is normally used for track mounting on overhead doors. It has a 3" operating gap. Another is the 2515AL with a stated gap of up to 6". The 2747A-L has a gap of up to 2". I've used that one on a few sites as well.

Heh, heh, heh... :^)

Yep. It's almost impossible to keep them aligned more than a few years.