Alarm question: Leave Walk test LED on or off?

[Dog80]

Most PIR detectors I've seen have a jumper for enabling or disabling the walk test LED, ie. the (usually) red light that flashes whenever the detector is activated.

Is there any reason to disable the walk test LED?

[gotpasswords]

About all I can think of is stealth. If someone peeking in through a window doesn't see a light, they may not think there's an alarm sensor in the area, but that defeats the whole point of having the alarm system.

Stickers in the windows, red lights and other things that say "There's an alarm system" are "preventive" controls - ideally, a crook will see them and leave your house alone. If the alarm doesn't make its existence obvious, it then becomes a "detective" control and only makes its presence known after a crook trips a sensor.

Of course, you might want that - a silent and non-obvious alarm can become a "corrective" control if the police are able to respond and apprehend the crook.

[The_Raven]

Stealth is irrelevant. The light won't come on until the motion detector is triggered. By then, it's too late for the intruder.

In a commercial application, it may not be a bad idea to disable the LED if you are worried about employees with free time on their hands discovering a unprotected path or area.

At home, it is useful to leave it on to give an indication that the detector has power and is actively detecting. As for whether the alarm control panel is seeing the relay on the device trigger, that is another story, and should be tested separately by watching the keypad to see if the zone is triggered when the area is traversed.

[BigT]

Is it very bright? If not, I can't see any reason not to leave it on.