Class iii

[TALK]

Just tested for a new client about 90 appliances.My tester does Class 1/2 and IT.Class III for appliances under 50volts I came across 4 off.2 Laptops and 2 Telephones with transformers etc.The transformers don't have Class III symbols but are under 50 volts.So I always test as IT.

How would you safely test a Class III appliance.

The report came back with a note,Please complete CLASS III appliances.

Thanks in advance.

 

[i=p/u]

just say they need visual??? aint got my book to hand , if it even says much about class III

 

[TALK]

just say they need visual??? aint got my book to hand , if it even says much about class III

Your correct it does not say much,although insulation resistance reading says 250k omhs.I always consider CLASS III as IT,the person who sent back the report must have some experience to do this.

COP says 250k omhs,usually I test the leads only on the primary side of the transformer,230v.

My Megger tester has no CLASS III setting,and most Fail applainces like this because of surge protection.How do we get a 250k omh result downloadable on a pat tester for printing on to reports.



Thanks.

 

[i=p/u]

visual inspection , and depending on the type of equipment and location is retest dates, as you know as for testing it looks like just insulation resistance and if you cant test at the voltage required , cant you do touch current test or something, hand write the result

 

[xraytek]

The transformers don't have Class III symbols but are under 50 volts.So I always test as IT.

Are you referring to the output voltage when you say 50V?

Whats the input voltage, because if its 230V then the equipment is Class II?

 

[truckster]

.I always consider CLASS III as IT,the person who sent back the report must have some experience to do this.

Or not

From Parker Bell
"A Class III appliance operates at less than 50v and therefore does not need to be PAT Tested. However. The lead used to charge many low voltage electrical items (like mobile phones or laptop computers) is usually a Class II appliance and should be tested as such.
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How do I make a visual inspection?

Before you begin to carry out your PAT Testing it is vital that you carry out a thorough visual inspection. You should check for the following:

* There are no cracks, loose parts or screws.
* There is sign of damage to the outer casing, burn marks or stains.
* Cables are not damaged, crushed or grazed in any way.
* Check the plug to ensure there are no cracks in the casing and that the pins are not bent or damaged in any way.
* Check that wires are attached to the correct terminals and that no bare wires are visible other than at the terminals.
* Terminal screws must be tight.
* Check that the correct fuse is inserted.
* Check that the cable clamp is securely fitted over the outer insulation cable

It is good practice to put a fuse label on the plug detailing the correct fuse value that should be inserted."