Horiz Sliding Windows (Sensor Location)

Almost all of my windows are horizontal sliding windows (aluminum). Based on your experience can you tell me the best place to mount the sensors?

I was planning on using closed circuit contacts but maybe the plungers would work better for this?

i.e.
Upper right corner
Lower right corner

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Depends on where you have access to run the wires.
Ideally, as in for pre-wire, the magnet and switch should pull directly away from one another. So you would want the contact along the vertical jamb so the window opens directly away.
You could use plunger type contacts in this same position.
That's hard to do in a finished house unless you want to pull the trim.

I placed mine in the bottom track on the lower floor windows and in the upper track in the upper floor windows.
If you open the window all the way you should be able to lift out the sliding pane and frame and put the magnet on the window and the switch in the track.
You may be able to use roller plunger contact on the bottom of the track. But that may affect the way the window opens and slides.

NEVER use plungers or rollers on a window. That's a false alarm and maintenance woe waiting to happen. There's always some other way to install a magnetic contact on 99% of the windows.

It makes no difference if the magnet directly pulls away or if it moves in a parallel direction or not. The biggest thing is making sure it moves enough to generate an alarm, but should not be an issue on a slider window. Contacts and magnets work the same way irregardless of how they're oriented, as long as they're installed properly.

As I understand it (info gathered from this site), straight pull away is preferred for magnetic contacts because over time a sliding across motion will magnetize the switch (similar to drawing a srewdriver across a magnet several times will align the molecules and magnetize the screwdriver) and lead to problems.
However, sometimes you can't use the preferred method.

I did not want to remove the trim from my sliders so I did put the magnets and switches such that they slide across one another. They've been installed just a year and I haven't had any problems yet.

I wouldn't use plungers here either, I perfer the magnetic contacts.

I understand plunger problems in the lower track due to dirt getting into the switch.
What would cause switch failure of a plunger in the side casing?
I can't imagine much dirt flalling sideways into the switch.
No more than a door anyway.

Desert_AIP said:

As I understand it (info gathered from this site), straight pull away is preferred for magnetic contacts because over time a sliding across motion will magnetize the switch (similar to drawing a srewdriver across a magnet several times will align the molecules and magnetize the screwdriver) and lead to problems.

Click to expand...

I'm sure that's a rare occurrence, while technically possible. My last house was prewired when built 26 years ago with the magnets sliding away rather than pulling away - and they still worked flawlessly.

That's good to know (since I have several).

Probably depends on how often the window is opened.

Thanks

Reed switches are magnetized during manufacture, it's how the fingers of the reed switch stay separated when the magnet is removed. It's slight but it's there.