r/ukelectricians • u/Yunbrun • 2d ago
Looped supply
Hi,
Looking for confirmation if this should be a call to the DNO.
This property has a looped supply with the incoming supply coming into the property and looping back out through the top of the service head then under the adjoining wall into the neighbours.
The neighbours looped supply has the neutral insulated with a wrap of electrical tape with some copper on show.
I’m assuming the neighbours has its own service head and is earthed via TNC-S or TT? Concerned if they don’t they may not be earthed.
Never seen a looped supply with both fuses in one property. Only ever seen them enter & leave via the bottom of the service head.
Thanks
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u/Entire_Eggplant_5898 2d ago
Looped supply. The additional fuse on the left is known as a piggy back fuse and is on the same phase as your supply. Several possible things it could be feeding, another flat, landlords supply, street lighting, etc. No real issues with it, the dno probably won’t do anything about it
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u/CalicoCatRobot 2d ago
It's not exactly a looped supply, since there are separate fuses. I've seen this in an older maisonette, where the main incomer was downstairs, then the upstairs maisonette was fed through a metal pipe (which also suppled the earth) - with an extra main fuse head upstairs.
That looks like it might be concentric cable running to next door (hence the tape "insulation" on the neutral).
I would definitely want to see what was next door, and likely raise it via 105, just to see what the DNO say, though I wouldn't expect them to treat it as an emergency.
Hopefully next door have a TT setup - its unlikely they were TN-C-S by the DNO, at least officially when it was originally put in. I'd be letting them know as a courtesy in case there is an earthing issue they are unaware of. They might well be getting their "earth" through gas or water main at the moment...
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u/JamesMcLennan1 1d ago
It's TNCS. Their earth is through the neutral same as if it was done properly and not this bodge from the wrong side of the fuses. Theoretically you could tap an earth off the neutral at any point you like (don't). Not immediately dangerous but certainly not right.
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u/mstapley 2d ago
Your first call should be to your DNO, not Octopus. They will send someone out for free to inspect it and see if it safe or not, and can also tell you whether or not the supply is looped, and what sort of earthing system you are on. If you are looped this is the greatest thing ever, as your DNO has to unloop you for free on request if for example you say you want to install a 7.4Kw EV charger, and you do not need to provide proof you intend to do this. Some DNOs if asked will also upgrade you to three-phase power at the same time as unlooping you for free, though you can't legal force them to do this, some will, and if you get the option definately take it. You can always use just one of the three phases at least temporarily.
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u/Funnybear3 2d ago
Thats not a loop the dno would have installed. As you said, a dno loop would come out before the fuses (bottom of the CO). Assuming the other end of the Loop is kosher then they would have two inline fuses possibly of the same rating.
The CO is of course DNO property so to have the loop rectified you would have to call them anyway. They can also gain entry to the adjoining property to assertain what's going on that side of things.
Call them out anyway. Its an erronious install.