How to Test & Tag an Iron
Main points to remember:
- Find out if it's Class I or Class II appliance
- An irons supply lead is made from cotton, as opposed to plastic
- It's especially important to check if this cotton is splitting
- Irons can be difficult to find any exposed metal, as newer irons are covered in a non-stick coating
- A good position for exposed metal is the gap behind the main heated face
- It's highly suggested that you also do a Leakage Test
The process of testing and tagging an iron is similar to other appliances, whereby we first need to confirm if it's a Class 1 or Class 2 appliance during the visual inspection.
However, before we get too far into testing the iron, we first need to closely inspect the supply lead much more carefully than usual. This is because the iron supply leads have an outer insulation made from cotton that provides not only electrical insulation, but also heat protection from the iron itself if rested on the supply lead.
Visual Inspection is Vital for Irons
A normal supply lead has plastic that would quickly melt if touched by an irons heated plate.
Unfortunately, this cotton insulation is not as mechanically strong as the normal plastic outer. If the lead is allowed to twist and knot, it can form a kink in the lead that splits the cotton threads apart exposing the primary insulation (coloured wires).
While it is a fail anytime we can see the coloured wires due to damage to the outer insulation, this is a particularly dangerous situation as the irons hot plate caneasily melt the primary insulation away, exposing the live copper conductors.
This is something that can be easily missed by the user, so we need to take out time to ensure the cotton is not showing signs of spreading and that there aren't kinks starting to form in the supply lead.
It's Time to Test & Tag the Iron
Based on the irons class we set up and prepare to test on our PAT tester.
Most irons are Class 1 and we therefore need a piece of exposed metal to have a successful earth continuity test. The challenge here is that the only exposed metal is likely to be the face of the iron that does all the work. Nowadays this is covered in a non-stick coating that prevents us from obtaining and good metal to metal connection, hence the earth continuity test fails.
We don't want to be scratching this non-stick surface, so we have to find somewhere else.
If you look at the design of the iron, there is a gap behind the main heated face that enables ironing of pockets and seams etc. This gap is usually large enough to get our test probe into. If the coating has extended into this gap, you can safely scratch a little of the coating to expose the metal beneath, without damaging the working face of the iron.
Important to note, if you don't have a probe you can use a stainless steel metal skewer, held in your crocodile clamp – it works really well!
Once you have successfully achieved a pass result for earth continuity, leave your probe in place and continue with the rest of the test sequence on your portable appliance tester. If the iron is a Class 1 and you can't find an earth even after scratching through the coating (in the gap) then the test is a fail and the iron must be removed from service.
As it is difficult to work out if the iron thermostat is open or closed, it is highly recommended that the appropriate leakage test is performed as part of the test. AS/NZS 3760 requires the leakage test to be performed if we can't [or aren't sure] test the entire circuit with the Insulation Resistance test.
Best practice is perform both tests and you can't go wrong.
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