help with the existing wiring of a 2 bed house

[Zehroni]

Just acquired 2 bed property which has the old fuses with wire consumer unit. My electrician will replace the consumer unit with new one and issue DOMESTIC ELECTRICAL INSTALLATION CONDITION REPORT. However, I have inspected the wiring of the property today so that I can sort out/ rectify any issues before his visit. The below has been found and would be very grateful if I can get help;

1. All the house power sockets (including the kitchen) are on one ring circuit. However, there are 2 sockets in the second bedroom are connected to one wire. All others are connected to 25mm twin wire with earth. How would that be possible? Does this mean that there is a junction box somewhere under the floor broad where one wire was branched out to those sockets. If so, is that legal? The total number of socket are 10

2. There is 6mm wire connected to consumer unit at one end (30am fuse) and terminated in a single socket in the kitchen for the extractor. Another single socket connected to this single socket (below it) to operate the oven (2.5mm wire). And the oven socket is also connected to another single socket via 2.5mm wire to operate the washing machine. In other word, 3 single sockets are connected in series the first one is fed by 6mm wire and the other 2 via 2.5mm. is this allowed?

3. I am hoping to separate the kitchen, upstairs bedrooms, dining and sitting room each on different power circuits. Do I need to rewire the whole house or can I modify the exiting wiring?

 

[Murdochcat]

Impossible to say - i would recommend you talk your findings through with your spark and then make decisions

Saying that there is a very big estate near me l with single socket circuits and circuit breaker failures are quite common

The spark shouldn’t be issuing an EICR - if you are in England or wales they must issue you with an EIC and a part p notification

 

[securespark]

I would rip it all out and start again.

You have only one power circuit.

You have issues on that circuit and the radial in the kitchen.

 

[pete01]

Get it tested first, maybe not necessary to rip it all out.

My house had an old rewireable fusebox but the wiring was perfect untouched since installed probably, so I kept it.

 

[flameport]

Do I need to rewire the whole house or can I modify the exiting wiring?

Unlikely to need to rewiring - but with only 10 existing sockets and multiple alterations/additions required it will probably be just as quick to start again and forget about whatever problems may exist with the old wiring.

 

[ebee]

Flameport is correct.
It might not actually need rewiring, however it might do depending upon whatever remedial works are required.
It gets to the point where a rewire is sometimes the most prudent course of action.
Personally I would do an EICR first and then advise on the most prudent course of action to consider.

 

[ericmark]

I would add, if you are going to have two ring finals, better if split side to side rather than up/down, as then should any fault mean you can't use one ring final, an extension lead to keep things running would not need to run up/downstairs, and the two ring finals would be more even loaded. The idea of up/down split was when we only used two RCD's and did not want the lights and sockets in the same room on the same RCD. Today with all RCBO's that is not longer a problem.

 

[ebee]

There is something in what Eric says there.
Also, traditionally it was more convenient to lay circuits, say lighting radials on a per floor basis and sometimes power too, whether rings or radials ( or both) but sometimes the kitchen might be better on one power circuit and the rest of the house on the other (or yet another ring or radial) . Another consideration might have been if
Then we started adding RCDs, firstly as a front end on the whole installation, then as a split for A/ Lights and B/Power (including on TT systems) then taking RCDs off lighting and then traditionally the dual RCD scenario and lastly separate RCBOs for each circuit.
Some of these might include if some sockets were "drop fed" along with others that were "up fed" it would all depend upon the layout of the house and likely power requirements too and circuits lengths considerations and cables costs.
There is no one size fits all scenarios but often there were bog standard ways you might go about common layouts and layouts could differ a bit depending on fusewires/MCBs/RCDs/RCBOs/Split/Dual RCDs,/costs/layouts etc. You might find that in a local Area or in a certain Era there were lots of common thoughts and practices too.

 

[Ragnar_AT]

1) You mean all sockets have two T&E cables and those two only have one each? That would likely suggest that they‘re unfused spurs and there’s junction boxes under the floor. They should be replaced with maintenance-free junction boxes.
2) This could probably be rectified by running 6 mm2 from the extractor socket to the oven, so only the washing machine socket is on 2.5.

 

[Zehroni]

I managed take off the floor board and chase the wires for the power circuit and to my surprise it is all radial on 2.5. wires, see attached pictures. It is not what i initially thought (on ring circus).

what is the best solution to create as much ring circuits as I can? all the wires are in very good conditions.

 

[Murdochcat]

If that sketch is correct it’s a bodge

Best you get it tested properly to confirm this first before you do anything

 

[Zehroni]

This could probably be rectified by running 6 mm2 from the extractor socket to the oven, so only the washing machine socket is on 2.5.

I was thinking to run 4 mm2 from the extractor socked to the oven (it is 13 am oven) and another 4mm2 from the oven socked to the washing Machine

 

[Zehroni]

If that sketch is correct it’s a bodge

It is very accurate, I chases every wire and did continuity test to make sure the correct wire going from one socket to another.