PIR sensors and electrical safety

Almost a year ago, an electrician in Victoria received a shock while making adjustments to a passive infrared (PIR) sensor. The PIR was not isolated and after removing the cover the electrician touched metal parts that were live.

Energy Safety Victoria is reminding electricians to always double-check power has been turned off before conducting maintenance, repairs, alterations or adjustments to electrical equipment. “A safe system of work must be used to minimise the risk of electric shock. This includes considering what actions to take before removing the cover of any electrical equipment.

“The golden rule is — before any repairs, maintenance, alteration or adjustments on fixed wired equipment, you must isolate and lock out ahead of removing covers, and test before you touch.” The electrician received a shock while installing a PIR sensor of the type and construction identified below.

Example: External construction (left) and internal view (centre, right) highlighting areas of exposed live parts.

This type of unit is most commonly installed in commercial or industrial premises. To test the sensor and adjust the settings, a common practice for electricians is to remove the cover normally secured by a retaining screw and use their finger to cover the PIR sensor head to simulate darkness.

ESV has identified that there is a significant risk of electric shock from these PIR sensors during installation, service or maintenance work. When the cover of these PIR sensors is removed, the user is exposed to live parts including the mains terminals and PIR sensor head (240 V~). These parts are highlighted in red across the images above. Touching the PIR sensor head could result in severe injury or death. Maintenance and adjustments to settings must be carried out with the power isolated, and by licensed electricians only.

PIR sensor heads must never be touched. Sensors of this design or construction should feature a warning label. ESV has produced warning labels which may be attached to existing PIR sensors.

This label is to be used with the identified PIR sensors only. The label must be affixed on the side of the PIR sensor closest to the screw entry. To place an order for PIR sensor Warning labels, click here.