How to tell the difference between Class 1 and Class 2 Appliances
One issue which crops up frequently during PAT Testing is the requirement to tell the difference between a Class 1 and Class 2 appliance. Actually – telling them apart is very simple – a Class 2 appliance will bear this symbol:-
Note the that IET Code of Practice refers to the ‘Class’ of the appliance as the ‘Equipment Construction Type’
In very simple terms, a Class 1 appliance will have an earth connection, and a Class 2 appliance will not. If the appliance plugs into the mains, then it’s either Class 1 or Class 2 – the square box symbol tells you it’s Class 2 – if there’s no symbol then it’s Class 1.
There is NO SYMBOL for Class 1!
Of course, you could look inside the plug – a Class 2 appliance should only have 2 wires (brown and blue) whereas a Class 1 will have 3 wires (brown, blue and green/yellow) – however – it is not unusual to find appliances which have been rewired or modified (bodged) with the wrong cable, so the only way to be sure is look out for the Class 2 symbol.
Note that Class 1 and 2 applies to 110V appliances just as 230V appliances.
This picture shows the Class 2 symbol on a 110V drill.
This picture shows the rating plate from the underside of a toaster. We can see various symbols, but NOT the square box symbol, so we assume the appliance is Class 1.
Please note this is a slightly simplified document designed to provide guidance to people carrying out PAT Testing. For more advanced guidance, please refer to the appropriate appliance standards, as well as the IET Code of Practice.