We often find Class 1 equipment with no obvious exposed metalwork to connect the earth bond clip

We often find Class 1 equipment with no obvious exposed metalwork to connect the earth bond clip and get asked how to PAT test such equipment. It’s probably best to split this type of equipment into three groups

The first group are mainly plastic encased and difficult to find a place to get an earth connection. Typically items such as fans, flat screen monitors and shredders fall into this category. The most useful piece of test equipment in this case is a long reach probe. Most modern test instruments use a standard 4mm test lead with a crocodile clip. These can easily be replaced with a 4mm probe. It may take a bit of practice at first, but you can quickly learn where to find an earth connection using a probe. An earth connection can usually be found on flat screen monitors and TVs by using a probe on the threads on one of the four mounting holes on the back. Obviously you need to be careful that you don’t put the probe too far into the hole and risk damaging the monitor.An earth reading can usually be found on the motor casing of a Class 1 fan. You will need a long reach probe to access it through a vent on the back.An earth probe is also useful for items like this coffee percolator. The earthed metal hotplate is cover by a thin paint or non-stick coating. Use a sharp probe in a discrete area to pierce through the coating.