Another home wiring puzzle

I did a circuit simulation model at the time:

Firstly that's unlikely in practice, and very unlikely for them to run for long.

The cable would run hot, but not hot enough to be a hazard.

NT

They might - but that is a bit optimistic - 5 mins sound more likely.

(and in a CU of that era a BS3036 rewireable would be more likely than a cartridge fuse I would have thought)

Yes. The open wire fuse links used in 1930s fuseboxes would have been the most common in the 40s - were they BS3036 compliant?

Ah - if BS 1361/2 came about in '47, 3036 was presumably much later.

Anyway, yes it would blow eventually, but the scenario would not be common & was still safe.

NT

Our House is late 40s Semi (ex local authority) and probably rewired 60s / 70s. We have a lot of circuits compared with most, and most sockets only have one T&E. Most crcuits cover a some or more sockets upstairs and downstairs. I decided as I wasn't sure of the topology of most of the circuits to have them fitted with 20A MCBs rather than 30A when we had a new CU. We've only tripped once tripped a circuit by pulling too much consecutively, and we just moved the cement mixer onto a different circuit for the day. I did do a continuity test in the CU on one of the suspect circuits the other day and it does appear to be some some sort of ring (at least in parts (but I realise this is simple test is no guarantee of anything). I found out the hard (amd painful) way that the circuit previously labelled upstairs Power wasn't! I now also test to make sure things are dead before I stick my screwdriver in!