How much to replace old consumer unit

[JohnD]

Ask round friends and neighbours to see if they recommend someone local.

Have a look at work he has recently done and ask the homeowner how satisfied they are. Contact two or three.

Phone and ask if he is a member of a self-certification scheme, and which one

Confirm that you will want an Installation Certificate at finish.

Most of the cost will not be in the supply and fit of new CU, but in testing (and probably rectification) of all the old circuits connected to it.

 

[securespark]

Post us a piccy of your supply cable....

As others say round here, "We like pictures!"

 

[JamesHughes]

I've only been in 3 weeks, so don't know anyone yet, but partner takes sprog to toddler group which is good for meeting people so hopefully that will help.

For the supply cable pic - is that the cable as it goes in to the meter etc?

James

 

[securespark]

Yes. Include the meter and the main fuse cutout & as much of the supply cable as your picture will allow.

 

[JamesHughes]

Here is piccy of outside supply box

http://i175.photobucket.com/albums/w143/JamesHughes_photos/DSCF2237-1.jpg

James

 

[JohnD]

Is that all for your house? Have you got an unusually large installation, swimming pool, smelting furnace, X-Ray machine, milking parlour, pottery kiln or something?

 

[Steve]

I think!!!! You have a 3 phase supply. Never a bad thing (apart from normally higher costs for wiring)

So your electrician might want to put in a 3ph DB to make it easier to balance the phases. At the moment, We cant tell you much, but it doesn't looks like the phases are very well balanced due to there being 2 single phase CUs.

The electrician may simply use one phase for the whole lot, it may depend on how its been wired before. If you dont take advantage of the night rate metering you have (storage heaters), consider changing to single rate as it might work out cheaper for you.

 

[JamesHughes]

Blimey - if I have a three phase supply that would be good - got a couple of bits of machinary in the garage that I have to use a single -> three phase convertor for (Lathe and Mill). So, if in place that would be good!!!

No idea why it would be three phase already - unless something to do with fact its an old village police house, although hasn't been for at least 12 years.

I've been in less than 1 month, but previous owner didnt seem to have anything requiring a huge amount of power. No pool or anything like that.

All heating is gas fired, no storage heaters.

James

 

[JohnD]

yes, it is.

You have a 3 phase supply and meter.

I think you could do with a cheap clamp meter, then you can see which phases are in use.

Each of those grey fuseholders is for a different phase. The Neutral is common. You have PME. You also have an off-peak supply but this may not be on the domestic E7 tariff.

You will need an electrician who is used to both commercial/industrial work and domestic. One who works in agriculture wouold probably have the right experience.

Beware, voltage between phases is about 400v which is more often fatal than the common 230v, so it is safer only to use one phase in any one room or any one floor of the house.

Since retiring from the Brinks-Mat warehouse at Heathrow, I have been using my smelting furnace concealed in a walled-off cellar. Maybe you have one hidden away too.

 

[JamesHughes]

Getting abbreviation overload here!!

3ph DB ??
PME ??

Don't worry about voltage - I don't touch this end of stuff with a barge pole, even an insulated one.

Haven't checked for a cellar.....

James

 

[JohnD]

3 phase distribution board. Generally bigger and a lot more expensive than a domestic Consumer Unit. Generally also much sturdier and better quality. Usually grey-painted metal. If you only have a domestic installation in the house I might go for an ordinary domestic CU fed from a submain in the DB, and a small DB in the garage/workshop. If the supply from the meter enters through the garage this would be easier to arrange.

Protective Multiple Earth. A modern and reliable method of earthing provided from the network.

 

[JamesHughes]

I presume that the PME would explain why the earth stake in the ground doesn't appear to have anything attached to it...??? Safe to dig it up?

House is purely domestic, so I would prefer the CU route through cost reasons. Would need some sort of 3ph DB (see, using those abbreviations already!) in the garage I guess. Unfortunately, garage is to side of house, so need to put in a 3ph line from supply box on front of house round house to garage. Are these usually underground? Garage is not attached to house so would need to go over/under path to get there.

James

 

[Adam_151]

Getting abbreviation overload here!!
3ph DB ??

Three phase distrubution board (a consumer unit is just a basic kind of distrubution board for single phase and reasonably light usage), a 3ph db is almost always metal and has the breakers mounted round the other way http://www.tlc-direct.co.uk/Images/Products/size_3/WYPSTN81.JPG

PME ??

TNC-S earthing (the earth is derived from the neutral in the meter cabinet - http://wiki.diynot.com/electrics:earthing_supply_types_and_bonding:earthing_arrangements) Often called PME (protective multiple earthing) as the neutral has to be tied down to earth (metal spike or tape in the ground) much more often than it would normally for the DNO (distrubution network operator - the people who look after the cables in the ground, the actual company varies from area to area) to be able to provide a TNC-S earth safely

That meter cabinet looks pretty new tbh, just trying to work out why it should be three phase because by the look at your consumer units, they probably pre-date the meter cabinet and I see nothing really requireing three phase (although I admit the storage heaters when they were in would've probably be on a separate phase) - do you have connection points around the place where heaters were once connected?

Oh, and have a look at that meter closely, see if it says whether it is a Kwh or a Kva meter

 

[JohnD]

Try to find out what cables already go between the meter and the cluster of CUs, and into the garage. Big cable is expensive. Burying it is expensive.

edited: Hee hee!

It's a watt-hour meter.

 

[securespark]

It is indeed.

And it looks like it WAS TT but has been converted to TN-C-S.