All electrical appliances using mains voltage have to deliver at the very least two degrees of safety to the consumer. This is to assure that if a single of the protection levels were being to are unsuccessful, there is the back again-up of the next layer however in location. This tends to make electrical equipment pretty safe and sound to use. Appliances can be Course 1 or Class 2.When PAT testing, it is important to initially detect the Class of the equipment as Class 1 appliances are tested differently from Course 2 appliances.Based on how specifically the security is furnished, electrical equipment are put into 5 Lessons of gear design which are Course one, 2, 3, , 01. Of these the most vital are Course one & two. For completeness all the Courses are described under.Course oneRight here the protection is delivered by a blend of insulation and use of the mains Earth. It is very best proven by referring to an electric fire that has been taken aside.In the open plug the 3 wires connecting to the Live, NEUTRAL and EARTH pins. Inside of the fireplace, the brown Are living wire and the blue NEUTRAL wire hook up to a plastic connector. The inexperienced/yellow Earth wire connects to the steel case of the hearth.The user is safeguarded from electric shock by the plastic insulation of the connector. This retains the Live and NEUTRAL wires in area and stops them from touching the steel circumstance of this electrical hearth. This plastic insulation of the connector is recognised as standard insulation.If this essential insulation have been to fall short, say due to extreme movement of the cable wherever it touches the steel scenario then the user of the fireplace can receive an electrical shock if not for the reality that the EARTH wire is present.By connecting to the steel case of the electric fireplace, the EARTH wire keeps all this metallic at EARTH opportunity. What this means is that it is unattainable to get an electric shock even when the metallic case of the hearth is related immediately to the Stay voltage. In apply a fuse would blow both in the plug or the major fuse box to guard the person.In summary, in Course one appliances the consumer is safeguarded by a mix of simple insulation and the provision of an EARTH link, hence supplying two concentrations of protection.When PAT Testing Course 1 appliances, the Earth Continuity and Insulation Resistance assessments are carried out.Class 2In a Class two equipment, the person is shielded by at least two layers of insulation. For this reason, Course two appliances are also recognized as Double Insulated. They do not call for an Earth connection.This is greatest proven by on the lookout inside a Course 2 electric powered drill which has been opened up. Within a person can see that as properly as the plastic connector delivering essential insulation, there is additional insulation delivered by the plastic enclosure of the drill.The consumer is for that reason protected by two individual levels of insulation. When PAT testing Class 2 appliances, just the Insulation Resistance check is carried out.Course 2 appliances are constantly indicated by the double box image on the rating plate.Course threeMachines created to Course 3 common are intended to be equipped from a distinctive security isolating transformer whose output is identified as Safety Extra-Small Voltage or SELV. This will have to not exceed fifty V AC and is ordinarily is underneath 24V or 12V. All Class three appliances are marked by a special symbol. There is no use of an Earth in Class III equipmentThe electrical safety of Course 3 appliances are taken treatment of in the protection isolating transformer structure exactly where the separation concerning the windings is equivalent to double insulation. The transformer is marked as remaining suited for use with Class III appliances.Class & 01This style of tools is not for normal use in company or residential environments. It is just presented below for completeness.Course appliances rely only on primary insulation for defense from electric shock. For this explanation, they do not have 2 concentrations of safety created in and are not authorized for sale. The brass lamp demonstrated listed here is an example of a two wire, steel cased equipment with only simple insulation. There is no provision for link of an earth to the bulb holder.In Course 01 appliances, there is provision for an Earth relationship, but it is wired with either twin main cable or only has a 2-pin plug, so an Earth are not able to be related. AS in Class tools, 1 is dependent only on basic insulation for safety from electric shock. As they only have 1 degree of security, Course 01 appliances are not authorized for sale.If all through PAT screening one particular will come throughout a Course or Class 01 appliance these can be unsuccessful.Determining Class I & Course II ApplianceAs the PAT tests carried on Class 1 and Class 2 appliances vary, it is vital to discover 1 from the other. There is no other space of PAT screening that results in much more confusion than this and there are several myths bordering this. Villanyszerelés Budapest It will be instructive to record some of these.If there is a fuse in the plug, then it will have to be Course one.It is built of steel so it have to be Class 1The circumstance is plastic so it need to be Class 2It has a a few core cable so it have to be Class oneThe plug has a steel Earth pin so it will have to be Course 1None of the over statements is a idiot-evidence way to determine Class I and Class II appliances and some are fairly deceptive.The best rule to utilize is the a person down below.If the ranking plate has a double box then the equipment is Class 2. If it does not then it is Class one.Case in point - KettleThe ranking plate on this kettle clearly has no "double-box" symbol, so utilizing our rule, it should be Class 1. The Earth relationship from the plug is terminated on the outside the house metallic casing of the heating component. When PAT testing this kettle the Earth Continuity and Insulation Resistance take a look at has to be carried out.Illustration - Plug-prime ability sourceThe rating plate on this Plug-best transformer evidently displays the "double box" image, so this is a Course 2 equipment. Notice that it has a plastic Earth pin, as this is not essential for Course II. (Not all Class 2 appliances have a plastic earth pin). Just the Insulation Resistance examination has to be carried out for the duration of PAT tests.Instance - Mains extensionThe score plate on this extension is moulded in the plastic. It evidently does not have a "double-box" image, so it ought to be a Class 1. When PAT tests this extension guide the Earth Continuity and Insulation Resistance check has to be carried out.Case in point - Desk lampThe rating plate on this table lamp plainly demonstrates the "double-box" so it is a Class 2 equipment. (Observe that this is a Course 2 equipment that is mainly in a metallic enclosure). The bulb holder is made of plastic and delivers the required double insulation. Just the Insulation Resistance examination has to be carried out in the course of PAT testing.