Understanding this Henley Block

[qwertynb]

Hello all.

I am posting with the hope of understanding what is going on with this DNO cutout ( apologies in advance if I ramble a bit). I have just moved into a flat which I am renovating. I have a reasonable understanding of electrics after the electricity meter but do not know much about what happens before it. I will say in advance that I do not intend to mess about with anything related to the DNO, rather I want to understand what is happening and also be a bit more knowledgeable when speaking with the UK power networks.

So here is the setup:

There is a single supply that ultimately supplies 4 different Victoria Flats in a looped supply.

I need to upgrade to 100A which I suspect is not possible with the current setup and the supplies may need to be un-looped. I went to have a look in the flat with the main incoming supply and was a bit confused about how it was wired between the different properties.

I have attached a picture for reference. There are three connections leaving this cutout . One to the persons meter, where the cutout is installed. One to the upstairs flat. and one that goes into the wall to supply the two neighboring flats .

I was looking at the cutout and can see that all the neutrals are connected together on the right hand side.but it appears that only one live is actually going through the Henley Block fuse ( Is this correct ?). The other two lives appear to come out of the left side of the block which make me think they are not fused at all in this location. (i do not know how these cutouts are wired inside so i could be wrong.)

Should i be concerned about this setup? My worry was that this setup relies on all the secondary fuses in all the flats remaining being correctly sized as to not overload the main cable. So if one of the flats upgraded to a larger fuse the overall system would have no way of regulating over current.

The person who the main incoming supply did however say that on occasion the whole supply has tripped which would indicate more a shared fuse but i not entirely sure i understood him correctly.

Any clarification on how this system works would be much appreciated and thanks for your time.

Regards

Nick

 

[333rocky333]

I would guess thats likely a 3 phase head with three up to 100 amp outgoing ways, to prevent issues with fuses blowing in someone elses flat they likely linked straight through and put each fuse and meter in the relevant flat.
The electric board seem to make up there own cable ratings, if it is spread across three phases then its likely the supply is fused over 100 amp per phase each externally even ,if the cable cable appears small, relying on the fact the maximum fuse to fit in the consumers fuse carriers would be 100 amp even if there currently fitted with 60a or 80a.
A picture of your supply may be more help as i assume this is not it.
From the above i can not fathom out what flat is yours, upstairs flat maybe?
Hard to tell what that cable is leaving the henley blocks, is it cloth covered VIR or just dusty pvc

 

[ericmark]

It looks like a three phase block, but with only one fuse used. I see two wires lower down, I assume un-fused supply to other flats, as to if three phase or not, can't tell.

However the fuse box show is rated 60 amp, and it seems the tails to other flats not big enough to all 100 amp, so seems likely they are also 60 amp. I would guess to up-grade to 100 amp new cables will need to be run.

I know my house three floors, two kitchens, two electric showers, oil central heating has a 60 amp supply, likely because it also had the old Wylex fuse box and the isolator in them was rated at 60 amp, I now have 100 amp isolator, but also solar panels, so still could not have a 100 amp fuse without some alterations, but could fit an 80 amp I guess.

Not sure why you want a 100 amp, but I think it will cost a lot of money to get one.

 

[Murdochcat]

Why do you think you need 100A - sounds a lot for a flat?

 

[qwertynb]

Many Thanks for all the replies. I do hope that it is a three phase supply, and that would be the most logical explanation. I wonder if the black connection block in between the meter and the cutout confirm this?. Presumably the fact there are two cables coming out of the bottom left into that black connector box would mean there are two supplies out of phase that need to be isolated from each other. Otherwise why not just have a single bigger cable to that black connector block?

So For clarification my flat is one of the flats labeled in the " Next Door Flats" connection. The supply one sees going into the wall travels to my downstairs neighbors supply and is looped at his main fuses to then go up to my flat. The loop occurs before his fuse so we effectively have two of our own secondary fuses running in parrallel off these two cables. This again to my untrained self seems dangerous as it really only looks like a 10mm^2 cable supplying two flats and if both our fuses are say 60A's that seems dangerous.

As to the type of cable. from my memory. The cable in the picture which goes from the henley block to the meter and from the henley to the black connection box are all PVC cable.

The older cables which run to the respective flats are all cloth covered

As to needing a 100A supply. I intend to install an electric boiler and electric hob which by themselves appear around 70-80A.

I am aware the neighbour also has an electric shower so I am aware that the cable labeled next door flats will likely need to be upgraded if the main supply supports this.

I will post some more pictures today which might be helpful.

Many Thanks again for all the advise, it really helps to understand things.

 

[qwertynb]

Hi All. Well I think understand the setup better now and recognize that that i am probably limited to a single phase 100A supply for two flats which is not ideal. But will contact the DNO and see if there is any possibility of pulling more power from the cable.

I have attached some pictures of the rest of the runs. Pic one being my neighbors flat which appears to receive one of the phases from the DNO cutout and pic 2 my meter/ fuse which is fed from his flat.

It seems like the DNO does not see it their responsibility to replace anything past the initial cutout so i may be a bit stuck in that respect and have to do some form of load management. I don't know if anyone has ever been in a similar situation regarding who's responsibility it is?

Many Thanks Again.

 

[pcaouolte]

That lot would benefit from an update (understatement). Are these flats rented? Love the Danger Keep Away sticker on the meter and terminals exposed in various open enclosures which are hopefully not in use.

 

[Murdochcat]

How are you heating the property at the moment? Electric boilers are VERY expensive to run.

 

[SUNRAY]

I'm assuming those 2 reds in the bottom of the Henley do come come out of the DNO fuse but from the unfused point, otherwise theye'd come out of the top exits.

Personally I'd call in DNO and ask for a FOC update.

 

[flameport]

. I intend to install an electric boiler

Forget about that.

Worst heating option ever.

 

[flameport]

I am aware the neighbour also has an electric shower

Another fail.

 

[SUNRAY]

Another fail.

Why a fail?

Please don't mention feeble or expensive as neither are accurate.

 

[flameport]

Supply inadequate.
Should never have been installed.

 

[SUNRAY]

Supply inadequate.
Should never have been installed.

I believe that is correct.

We have a looped supply and I suspect a 60A fuse which has never let us down.
I'ts difficult to identify the size of that rubber/cotton wiring and certainly not the fuse rating. but in reality I don't think our service is all that far behind the pictures although we don't have long unprotected rubber tails.

 

[qwertynb]

Thanks again all for the many comments. It seems like the consensus is then that the single phase that supplies the two flats is probably direct from the feed cable and unfused in the dno box and potentially supporting two 60a fuses in parallel on that single line. I wouldn't be surprised if it was over-rating the line and maybe just luck because of the domestic habits of previous owners that things haven't happened? Some houses on the same road had reported potential overloading and fire risk according to one of residents and appeared to be related to the tails wiring.


I too find the danger electrical sticker quite hilarious. Apparently someone came to have a look at the fuses and cracked open the meter exposing the cables and thought a sticker was an appropriate fix


In regards to electric heating. I am aware of kwh cost penalty vs gas. I am doing this from more of an environmental perspective. I am aiming to radically change the thermal properties of the building and utilise tarrifs (not going for electric combi) to make the cost of electric heating somewhat similar to gas although I am aware there will be a financial penalty.


So all the flats are owned with the exception of one which is rented.


I will try and sell this setup to the dno as unsafe maybe citing potential unfused and overload problems on one of the phases, old cables with exposed conductor. I am hoping this might be enough to get them to do something rather than the cost falling all on us.


I will keep things updated so others who may have similar issues know how the dno deal with this.