Anyone want a 100A ammeter?

You might find they run off current transformers.

Probably ebayable if no-one takes them.

NT

Those kind of things are always going at our local auction house. Make yourself a few bob. Take the phase meters, too.

Taking them is still theft!

They still belong to someone regardless of the apparent "lack of ownership" of the building.

Is it f*ck and nor is selling them or giving them away. They will be going into the skip or Ebay next week unless anyone wants them. And now I have got some lights on in the basement it turns out that they are maximum load indicators not ammeters.

As someone has already pointed out, at 100A these will probably be CT operated (100:5A at a guess). You'll need to either remove the CTs as well (probably rings round the mains cables) or short out the wires to them BEFORE DISCONNECTING FROM THE INSTRUMENTS. An open-circuit CT can produce a high voltage on the secondary if there is any load on the primary.

Quite often on an old max demand indicator there is a secondary pointer that is pushed up by the main one and needs to be released with a key or something similar, although there are manual reset ones.

Direct in line 25mm copper tails. And the power was disconnected 12 months ago.

I thought that you had meant something like that when you said: "that are no longer in use" in your OP!

Designed to be 'tamper proof' then. Well, that shoiuld end the speculation about the use of current transformers.