Timeguard provide their advice on PIR selection

Timeguard advise picking a PIR Detector that is specifically tested with and rated for the LED loads you need to control

If you have invested in branded quality, but the lights still aren’t working as expected, you may have an incorrect installation, or the wrong PIR for the job. Their difficult to reach placement makes replacing a faulty device an awkward job, so it’s wise to invest in the correct PIR for your needs. We asked Timeguard what you should be asking yourself before you choose a motion or presence detector.

What type of lights and what load?
No need to do the maths yourself; the specification on the box should state what LED loading is acceptable. Timeguard thinks it’s wise to add at least 10%, since there is a huge difference between ratings for the same PIR detector for halogen and LED. For instance, while Timeguard’s mini linkable PIR for is rated for 1000W max, the LED rating for halogen is 250W max. That’s because the LED rating allows for the strong inrush current on switching, not the subsequent low running current. That said, 250W is usually enough for these PIRs with the option of up to five pre-wired RJ11 plug-in slave units per master, allowing for quick installation for corridor and multi- zone use.

Will there be lots of luminaries?
Take care if the total LED load is getting near the limit of the PIR’s specification, especially with small luminaries. Their size means lower wattage LED lamps (GU10 type lamps) commonly have very simple circuitry with no surge protection and power factor correction. That puts a massive strain on whatever is switching or controlling them. The Timeguard SLW360o ceiling- mounted and flush-mounted detectors have a maximum LED load of 150W but are rated for a maximum of 10 separate LED 10W lamps (100W). The firm rates and guarantees them for LED lamps above 10W, right up to the 150W limit.

PIR Location?
A ceiling height of 2.5m will generally provide optimum coverage. You also need to be aware that highly reflective surfaces and heat sources like extractor fans nearby can interfere with sensitivity. Most reputable PIRs now offer more sensitive presence detection as they need to be able to detect the difference between an empty room and people sitting quietly at a desk – this comes as standard on most Timeguard PIR detectors. The Tech Team at Timeguard are always happy to provide their free advice, in addition to the information available on the company website, product packaging or instruction leaflets. Timeguard offer customers branded quality assurance – reliable products, information and free tech desk support for installers.


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