In the first post, pic 5, the W.C. area, look at the junction on the left. Looks like some fire has already happened there.
I'm not sure if that dark patch is overheating or just shadows when I took the picture or an unpainted part. I'll check when I get the chance.
pity the fire brigade that has to respond when this wiring lights the place up for real
Well, the good news is that the local fire station is only about 200 yards away!
(That is, if I understand "WC" correctly.)
I think you do!
Good luck if you plan to re-wire.
Yep, the tenant asked me about "doing something" with the wiring after his insurance agent became rather unhappy. Of course, given the present state of the wiring the only sensible option is to rip it all out and start over.
It must be a little confusing when you're not used to seeing this stuff, so let's see if I can explain it all!
In the first picture, is the large grey box in the lower right the service entrance?
Yes, the large black cable entering that service head from the right is the underground supply from the street. This is our standard 4-wire 415Y/240V system.
What are the 3 smaller boxes on top and why does one have three grey cables coming out of it?
These are part of the service head and are pull-outs which contain cartridge fuses (60A each phase in this case). There are always
PoCo-owned (and sealed) fuses between the supply and the meter here, whether a 3-phase commercial service like this one or a 1-phase residential.
The connections to the right of the fuses, still part of the service head, are to the neutral.
There are actually only two cables going to the right-hand fuse: Click for closer view
One of these loops down to the small black fuse holder on the right, and from there a smaller cable (along with a similar-size cable from the neutral) runs to the black box to the left of the meter, which is a timeclock. This is used to turn on the power to the storage heaters at night via the contactor which is the other black box at the bottom.
The cables bringing power out from the meter (you can see the three phases taped red, yellow, and blue) are looped behind the board and are the four gray cables you can see emerging in a bunch on the right, along with the two earth conductors which are connected to the neutral.
On the latter point, this is a PME or TN-C-S system, which is similar to the usual American grounding system except that this is the only point at which the the bond is made. Neutral and ground are kept strictly separate from this point onward, even in the main distribution panel.
The second picture with the unused 3 phase disconnect and the two distribution panels, what are the black things?
They are just heavy-duty junctions, commonly called "Henley blocks" for the name of a common make. There are two separate block in each unit, so the one on the left is being used to join one phase plus neutral (the one on the right is unused).
So, two of the phases coming from the meter run directly to the now-unused 3-ph disco. The third phase and the neutral are then tapped at the Henley block to go to both the 3-ph unit and the 1-ph main panel on the right.
Are there two cables cut off just below the storage heaters distribution panel?
No; it's not too clear from the photo but they actually turn and go into the heating panel.
One runs directly to the Henley block to pick up the neutral. The other (just about visible in the dirt at the bottom of the wall) runs back to the contactor, and of course the other cable from the contactor is the remaining cable you can see here which is tapped onto the phase.
Unfortunately, this sort of messy service equipment is all too common.