PAT Testing an Old Chandelier

[sillyphilly]

Hello, I am currently learning and have come across PAT testing an old chandelier.

On modern lamps I would use the plug and probe on the lampholder and wiring and put these straight into the PAT tester to test. But with this older chandelier, I am unsure and looking for advice. The insulation resistance is absolutely fine on the chandelier, checked lampholders and also the main wiring and wiring on the arms throughout. PAT tester comes back it is all ok and on inspection the wiring is all ok, no nicks or snags anywhere.

The one thing that concerns me is the earth. The earth continuity fails when testing the main 3 core wiring using the plug to the PAT tester and also fails when using the probe on each lampholder. The earth continuity does not fail when the probe is touching the base piece where the earth is attached on in the centre body piece of the chandelier with an earth tag (where all the wires are located).

Is there a reason this is the case? Or is using the probe on the centre body giving the pass for the earth continuity ok for this and you use the probe on the metal piece the earth is connected to? Rather than anywhere else on the chandelier?

I am currently training with using the PAT tester, and everything I am ok with apart from old antique chandeliers (This one is a typical french crystal and brass chandelier) This is a first for me, so was hoping for some advice and continue learning!

Thank you for any advice given or help, it is really appreciated!

 

[Lucien Nunes]

Hello and welcome to the forum.

You speak of 'pass' and 'fail' for the earth tests, but what are the actual resistance readings? Plug to canopy or bowl, bowl to arms / lamp holders? If we know how far the figures are adrift, we might be able to identify where the excessive resistance is coming from and what to do about it. Could it be corrosion and/or loose parts in the mechanical construction, so that there is no solid metallic path between them? A photo showing its construction would be helpful here.

Chandeliers are not often fed from plugs, and antique chandeliers were not usually earthed, so it sounds like the electrical parts may be newer / modified. E.g. someone might have attached a 3-core flex for demo purposes using a new earth tag on the bowl, on what had been a class 0 fitting, without regard to earth continuity from that point onwards. Certainly, one should be testing to all the points that require earthing and expect satisfactory results from them. E.g. if the lampholders need earthing but the resistance is only satisfactory as far as the bowl or arms, then the thing isn't safe. OTOH on a fitting with insulated lamp holders and sheathed internal wiring, it might not be necessary for all metal parts to be earthed, even though a terminal has been provided for the circuit cable.

Post pics and figures please...