Strange way to supply

Industrial EICR ongoing. Weird but interesting.
New single phase DB supply picked up from one way of old TP 3036 switch fuse left in ON position with isolator engagement removed. Presumably, to save isolating busbar chamber. A few points to question regarding EICR.
Wired in 6mm tails, for some reason. Domestic lads involved, it seems.

So they have taken a supply from the old board to the new board reusing the old enclosure for the cable run?

Having worked in a few schools, such things are not that unusual. The question is, is it safe?

Seen a lot worse, no worries. It's just additional IT stuff. Found seven CU's added to DB's already. All for the same reason. Guess what?
Seems safe enough. It was an unused switch fuse.
They just used it as a way to get round isolation of busbar chamber, using rewireable in line with cartridge fuse in the new box.
Switch assembly removed and isolator bar operated manually to switch on
then door screwed closed.
Just creating joints, so a good reason for thorough testing. I'll isolate at the rewireable, when possible and if it tests well, ok.
It might not be a rewireable fuse, the unused ones are wired in ordinary copper.
If so, not being used for protection.......but is cable of sufficient size?
Just interesting.

I don't get why they went to the trouble of disabling the mechanism - why? what does it acheive?

ipf said:

It might not be a rewireable fuse, the unused ones are wired in ordinary copper.
If so, not being used for protection.......but is cable of sufficient size?

Click to expand...

If thats the case, then asside from not being in line with manufacturer's instructions, then assuming there is a 60A fuse fitted to that new switchfuse then there is the potential to overload the 30A rated switch contacts in the MEM switchfuse, plus it looks like 6mm off the busbar to me.

You've got a piece of equipment that is modified from the manufacturers specification, resulting in a re-wireable carrier now without isolation and where one is working near live parts if removing / re-fiting it

Guessing its also got asbestos in it?

I think I'd probably be tending towards a C2 for that. Get a shutdown arranged, and you could have the new switchfuse properly supplied off the busbar and the old one off the wall and bagged up in not much more than an hour...

If they were going to come off it anyway, why not just come straight off it without the new switchfuse? BS3036 are still recognised, and if you wanted a BS88 you can order up a cartridge fuse carrier for that switchfuse. If it had been me I'd have probably put a 4 core in and a three phase DB in the server room as you are going to be limited to 30A/ph, gives a bit more scope for future.

Some good points there. Quite a big job with a lot of paperwork and prep to do for Test and Inspect. Defects fair enough, but remedials for the future. No more than 32 amp, by the way. Just one dado radial circuit with 4 d. sockets. Another story.
As said previously, probably domestic sparks involved. 6mm swa. Yet to see the socket looping.

I wonder where the certificate is for the previous work carried out including the modification to the switch fuse, they didn't even label the switch fuse to indicate the wilfull damage and potential danger they left, opening the cover gives immediate access to live parts where previously it required other actions to access the live parts

Found a fuse carrier with fuse removed but outgoer still connected. Old lighting replaced following alterations so had an idea what to look for and traced it to this hiding above a large sprinkler pipe.