Absolutely Shocking...

[First-time-buyer]

Made an offer on a house, to find that it is a 5 bedroom house with the old Wylex insertable MCB type of consumer unit.

Its only 4 way, which seems quite weird. 1x Lighting, 1x Immersion Heater which shares itself with the Power Shower Pump, 2x Socket circuits.

The garage is run from a double socket, and so is the lighting.

To make it all worse, the consumer unit is in a kitchen cupboard, with no exactly the most easiest access.

Additionally, the Hob and Oven are both plugged into a Extension Lead, then into a Single Socket drilled through the worktop.

Nice...

Don't think the funds are in for a re-wire right now, however we will be able to stretch to a split load board, cooker socket, and a 6mm T&E ran to the garage SWA.. and a new board in the garage.

Awesome..

 

[Taylortwocities]

Its not unusual. In teh old days houses typically only had one socket per room.

Think again about a rewire. The absolutely best time is before you move in. You can plan the locations for new sockets and services now.
It is very difficult and expensive and messy to rewire a house when it is full of people and furniture.

Note that installing a new consumer unit can only be done if the EXISTING wiring is up to scratch, it sounds like yours may not be.

 

[winston1]

Made an offer on a house, to find that it is a 5 bedroom house with the old Wylex insertable MCB type of consumer unit.

Its only 4 way, which seems quite weird. 1x Lighting, 1x Immersion Heater which shares itself with the Power Shower Pump, 2x Socket circuits.

The garage is run from a double socket, and so is the lighting.

To make it all worse, the consumer unit is in a kitchen cupboard, with no exactly the most easiest access.

Additionally, the Hob and Oven are both plugged into a Extension Lead, then into a Single Socket drilled through the worktop.
Don't nee

Don't think the funds are in for a re-wire right now, however we will be able to stretch to a split load board, cooker socket, and a 6mm T&E ran to the garage SWA.. and a new board in the garage.

Awesome..

Don't need a board in the garage. Run off a 20A MCB in house direct to garage sockets, and lights through a FCU fused at 3 amp

 

[ericmark]

If I think back to my grand fathers house the fuse board had I think 3 fuses.
1) Lights
2) Upstairs socket
3) Down stairs socket
By 1954 when my dads house was built we had moved to using the ring main but also we had more uses for power so still 3 fuses.
1) Lights
2) Immersion heater
3) Sockets
By the time my house was built 1980 we had added one extra fuse.
1) Lights
2) Immersion heater
3) Sockets
4) Cooker
Since that time we have it would seem added a little more every couple of years.

The lights now often split into two circuits, the sockets into three circuits, shower added, garage added, cooker split into two oven and hob, and if we were to follow the IET/BSi regulations to letter we should also have dedicated circuits for any other fixed appliance over 2kW so washing machine, tumble drier, dish washer will also have their own supply.
However the house is still supplied with a 60 - 100 amp fuse and one does have to question if we really need 14 way consumer units?

The main advance is the RCD although in some form these have been around for 50 years only in 2008 did the rules change meaning nearly all circuits are now RCD protected.

This is all well and good with a re-wire or new house but with a older house to split just 4 fuses into two RCD's means lights on one and sockets, cooker, and immersion on the other. Safety means we don't want a fault on a socket, cooker, or immersion to trip lights.

But really the half way approach does not work.

 

[AndyPRK]

which is where RCBO's are useful.
An MCB and RCD in one, but they cost ~£30

 

[EFLImpudence]

If the electrical installation is so bad on a house purchase then the price should reflect this to allow rewiring.

It depends how badly you want the house.

 

[winston1]

and if we were to follow the IET/BSi regulations to letter we should also have dedicated circuits for any other fixed appliance over 2kW so washing machine, tumble drier, dish washer will also have their own supply.

There are no regulations that say that at all. Some people reccomend it but no such regulation. If there was these appliances would not come with a 13 amp plug and probably no mains lead either like a cooker.

 

[First-time-buyer]

Unfortunately there are bigger things that need attention than a full re-wire.

Basically, we are not too fussed about bring the house up to 17th edition, with multiple RCDs in a consumer unit.

Instead, sockets, cooker on the RCD side, lights on the unprotected side. If we went with no board in the garage, then a unprotected side RCBO. In addition, all supplementary bonding.

The other options is... do nothing... which isn't really an option.

 

[bernardgreen]

If there was these appliances would not come with a 13 amp plug and probably no mains lead either like a cooker.

A dedicated supply to a 2 kW appliance can be a single 13 amp socket on a 20 amp radial.......

 

[ban-all-sheds]

Unfortunately there are bigger things that need attention than a full re-wire.

You may not need a full rewire, but if some of the wiring needs replacing then it needs replacing, and that's all there is to it.

The point that TTC was making is that doing electrical wiring is disruptive - cables are buried in walls, in ceilings, under floors etc, and you don't want to be hacking into walls and ceilings and floors after you've decorated and furnished the place.

Basically, we are not too fussed about bring the house up to 17th edition, with multiple RCDs in a consumer unit.

If you have a new CU installed then you have absolutely no choice - the work must be done to the current standards.

 

[JohnW2]

A dedicated supply to a 2 kW appliance can be a single 13 amp socket on a 20 amp radial.......

If it truly were 'dedicated', it might as well be a 10A radial, wired in 1.5mm² cable!

Kind Regards, John

 

[First-time-buyer]

Unfortunately there are bigger things that need attention than a full re-wire.

You may not need a full rewire, but if some of the wiring needs replacing then it needs replacing, and that's all there is to it.

The point that TTC was making is that doing electrical wiring is disruptive - cables are buried in walls, in ceilings, under floors etc, and you don't want to be hacking into walls and ceilings and floors after you've decorated and furnished the place.

Basically, we are not too fussed about bring the house up to 17th edition, with multiple RCDs in a consumer unit.

If you have a new CU installed then you have absolutely no choice - the work must be done to the current standards.

Of course,

All the way up to the separate 2way consumer unit they fit, splitting the tails etc.

oven - Hob. Cooker switch in cupboard with a socket. Oven plugged in. Hob on 6mm t&e

 

[ban-all-sheds]

All the way up to the separate 2way consumer unit they fit, splitting the tails etc.

If you have the space, have a full-sized one put in, then it can be populated during later rewiring.

Cooker switch in cupboard

No - not accessible enough.

6mm T&E ran to the garage SWA.. and a new board in the garage.

Leave the garage for now - just get the electrician to put an FCU in if there's too much spurred from the existing socket.

 

[ericmark]

As an electrician we have a problem. We have to issue either a minor works or an installation certificate to say we have done work which complies with the regulations.

We are allowed to replace or repair items complying with previous edition but not to add anything new.

So if we for example want to add extra wiring buried at less than 50 mm in the wall either we must use special cable like Ali-tube or use a RCD where it starts. Again a new socket also needs RCD protection.

So with an old installation every small job becomes a big one until a new consumer unit is fitted.

However fitting a new consumer unit must also comply with regulations and what is required is a little vague and down to interpretation. The main problem is:-

314.1 Every installation shall be divided into circuits, as necessary, to:
(iii) take account of danger that may arise from the failure of a single circuit such as a lighting circuit.
(iv) reduce the possibility of unwanted tripping of RCDs due to excessive protective conductor currents produced by equipment in normal operation.

The question is although using a MCB is always considered as the origin of a circuit also using a RCD can also be considered as the origin of a circuit. The easy way is the RCBO if the installation is TN with TT not quite so easy. To have lights and sockets on the same RCD is down to a risk assessment and it is considered having both the lights and sockets split into two circuits and the area controlled by one RCD will not include both the lights and sockets of that area. So if you have a problem and the socket supply trips it will not also plunge you into darkness.

However there are other methods of ensuring your not plunged into darkness and one could fit emergency lights which would also ensure safety.

This is in fact exactly what is done in the case of a caravan.

 

[JohnW2]

The question is although using a MCB is always considered as the origin of a circuit also using a RCD can also be considered as the origin of a circuit.

Not, seemingly, according to the BS7671 definition. It defines 'a circuit' as having a common overcurrent protective device - so if several MCBs are supplied by one RCD, they create separate 'circuits', despite the common RCD - which, as you say, is what most of us would say/think, anyway.

Kind Regards, John