All electrical appliances using mains current need to provide a minimum of 2 amounts of protection towards the user. This really is to make sure that if among the protection layers would fail, there’s the rear-from the 2nd layer still in position. This will make electrical equipment very dependable. Appliances could be Class 1 or Class 2.
When PAT testing, you should first find out the Type of the applying as Class 1 appliances are tested differently from Class 2 appliances.
For the way precisely the protection is supplied, electrical appliance they fit into 5 Classes of apparatus construction that are Class 1, 2, 3, , 01. Of those the most crucial are Class 1 & 2. For completeness all of the Courses are described below.
Here the security is supplied by a mix of insulation and utilisation of the mains Earth. It’s best proven by talking about an electrical fire that’s been separated.
On view plug the 3 wires connecting towards the LIVE, NEUTRAL and EARTH pins. Within the fire, the brown LIVE wire and also the blue NEUTRAL wire connect with a plastic connector. The eco-friendly/yellow Earth wire connects towards the metal situation from the fire.
The consumer is protected against electric shock through the plastic insulation from the connector. This supports the LIVE and NEUTRAL wires in position and prevents them from touching the metal situation of the electric fire. This plastic insulation from the connector is called fundamental insulation.
If the fundamental insulation would fail, say because of excessive movement from the cable where it touches the metal situation then your user from the fire will get an electrical shock otherwise for the truth that our planet wire exists.
By connecting towards the metal situation from the electric fire, our planet wire keeps all of this metal at EARTH potential. This means that it’s unattainable an electrical shock even if your metal situation from the fire is connected straight to the LIVE current. Used a fuse would blow in both the plug or even the primary fuse box to safeguard the consumer.