This one is a freaking beauty... For a long time one of my 5750WPLs would not work at night... All the programming was correct and it was on the network but the IR wouldn't detect movement when the Light Level pot was set to Full Darkness... The original 5750 installed 20 years ago worked without a hitch, never missed a beat until the seals failed and it filled with water, so I replaced it... I programmed up the new, unit walk tested it, and then set the pot to full darkness as per the previous unit. I walked away and didn't think another thing of it until one night I went out to area where the 5750 should be sensing my movement, and, nothing... WTF... I checked the programming and all was good and the PIR Enable function via the Touch Screen was set to Enable. So why TF wasn't it working?! I re-checked the programming and even the terminations and all was good. I spent a considerable time frigging around with no success... I even walk tested and it worked... WTF!! In the end I gave up and decided at some point I should invest in another 5750 because the sensing level pot was faulty. Eventually I did, and since my house was recently going through renos that required scaffolding I decided I'd wait for the scaffold to come down and then replace the "faulty" unit... I replaced the unit together with the exterior lights a week ago, I programmed the new 5750 up, did the walk test, and life was good, so I set the unit to full darkness. Last night I went out to check if the unit would pick me up... Nope - Lots of expletives were heard by the neighbours... Today I set the unit to daylight and did a walk test. WTF the unit is working... Now, there is a camera monitoring the area where the sensor is located. The camera is 5m above the sensor under an eave. This camera has been replaced 4 times over the years due to failure. The original cameras were Day/Night and used a Jaycar Long Range Bullet Type IR illuminator to illuminate the area monitored by the camera because the camera was not provided with built in IR because is was varifocal. The 3rd camera was a Ness Eyeball with built in illuminator and the current camera is a Dahwa unit also with built in illuminator. Late his afternoon as the light levels were dropping I decided to undertake a little experiment whereby I adjused the Light Level Pot a small amount towards full darkness and when the light level dropped below the hysteresis point of the sensor the light under it's control would come on, until I got to full darness and the units would not come on... More expletives. I knocked the pot back to Daylight and Bingo! The unit was sensing... Hmm... I wonder... I set the pot to full darkness and no more sensing. At that point the light bulb above my head exploded... It's the F@$king Camera. The IR emitted by the camera was providing enough (IR) illumination to stop the sensor activating. I tweaked the pot abot 5 degress back towards daylight and 5750 was sensing again. Well f@$k me! So, I figure that the problem commenced around about the time I installed the 3rd camera and removed the Jaycar illuminators, but because the I don't spend much time in this area where the camera is located I didn't notice the problem until well after. Also the electronics in the 5750s was updated to full surface mount technology in the early 2000s so Clipsal most likely tweaked the sensitivity of the IR detector when they updated the design and, modern cameras have much brighter and a wider IR spread than the Jaycar Illuminator. A trap for younger players and an older one too. Hopefully this will save others who experience this problem some time... I suggest Schneider to add this into the 5750WPL Trouble Shooting Procedures in the Installation Instructions.
