From covers on lamp posts to cases on power cut-outs, it’s not uncommon to hear stories of external panels becoming live due to an internal short. A quick search on Google will bring up several incidents reported over the years where casings from lamp posts and other street furniture have caused incidents due to internal shorts.

Find out more about how to safely detect live panel casings

This problem can also occur with distribution panels, resulting in a shock for anyone not wearing protective clothing coming into contact with it. More recently live voltages have been found on some older style domestic fuse cut-outs in residential properties due to the degradation of the insulation material.

The question is, what tools can you use to easily and safely identify this type of hazard? Non-contact voltage indicators won’t work safely in this scenario, as they can be susceptible to the signals from the cables and switches in the panel. The standard electrical screwdriver wouldn’t be ideal either, as they require you to act as the ground. This method means you need to make potentially unsafe direct contact. If you are wearing safety gloves then the electrical screwdriver would be of no use either.

Martindale VT7

The Martindale VT7 voltage tester solves the problem. It’s a single pole, contact voltage indicator that can be used to detect voltages from 50V to 600V AC safely. It’s safe because the unique design gives a clear indication of live voltages even when wearing safety gauntlets. The VT7 is the ideal tool for safe testing of casings prior to maintenance avoiding potentially unsafe direct contact with a finger or hand.

The advanced design features a built-in self-test function and can also be proved using a conventional proving device, such as the Martindale PD690. Indication of live voltage is clearly visible with the bright LED and an IP54 rating makes it suitable for indoor and outdoor use.

It should be noted that whilst the VT7 can be used to detect live hazards, it should not be used for proving dead. This procedure requires the use of a two pole voltage indicator, such as the Martindale VI13800 or VT25.