fitting an electric cooker

[tjmartin]

can anyone help? I am fitting an electric cooker and am fine with most of the wiring but am unsure about wiring into the consumer unit. I have read previous posts about how to get there with a control unit etc. I have a relatively old consumer unit which has removable fuses as opposed to switches. I am hoping to wire into a spare fuse - how do I know if there is a spare? if not, can I add an extra fuse to the unit - is this a job for an electrician or is it a feasible job once I know all the facts - any help is appreciated

cheers,

tom

 

[plugwash]

you could wire into your present cu if there is a sapre fuseway

but you should not use fusewire/fuses of a rating other than that maked in the carrier in a carreir so you will need to get a new carrier or a plug in mcb which may be easier said than done

also there is the possibility of overloading the cus main isolator by putting in such a large breaker

looks like a cu replacement is in order there is nothing impossible about doing this for a diyer but you must be carefull to make all connections well. Remember there is a lot of current flowing through those cables

your earthing arangement is probablly a TN-S unless you live in the countryside you can recgnise this by the main earth going to either the sheath of the armoured cable or to a terminal attached to the body of the service cable termination.
A TT means a rod and theese require special rcd provisions
A TN-C-S (also known as PME)means your main earth joins to the neutral main equipotential bonding needs to be done to the board provided ome terminal in this case and suplementry equipotential bonding needs to be much stronger

normal practice now is to use a split load cu with a main switch covering everything and a 30ma RCD covering some cuircuits in the case of a TT supply you have a 100ma type S rcd in place of the main switch

sockets that could reasonablly supply outdoor equipment must be on rcd
showers should be on rcd though regs don't require it
lights and alarams (an possiblly freezers too) should not be on rcd

what you do with the rest of the cuircuits depends on wether you belive in rcd on everything unless there is a reason not to or rcd only on things there is a reason to have it on

lights should be on 6A breakers

rings should be on 32A breakers (but make sure they are rings with a meter first if not then you need to find out what is going on and decide wether to replair the ring or split into 2 radials)

2.5mm radials should be on 20A breakers
4mm radials on 32A breakers

cookers and showers should be on breakers sized to match the device and cableing

when changeing the cu you will need to pull the service fuse don't worry about breaking seals on this to do it

the output tails from the meter may need to be replaced if the tails will have to reach accross the cu and they didn't in the old install replace with 25mm double insulated meter tail in this case

and get a board with at least 25% free posiblly even 50% is not overkill

get a mk sentry cu so you can easilly get new breakers later

if this is to daunting by all means get a sparky to do it but explicitly request a mk cu or a size that gives you enough space free

finally if you find rubber or worse lead sheathed cable your house really is desperate for a rewire

 

[mildmanneredjanitor]

Tom,

just my (unqualified) opinion, but if you inexperienced with electrics, the fusebox is not a nice place to start. Big nasty bangs can occur there!

However, IF and ONLY IF, you can isolate the power prior to the fusebox - turn off the power and remove the cover.

A copper strip (called a bus bar) will connect the fusebox isolator switch to all the fuse holders. Are there any spare prongs? Or are there any populated fuses with no wires connected to the 'output side' of the fuses?

If there is a spare way on the bus bar or populated fuse holder (unused), then this answers your initial question.

If you do have a spare slot then post again and I'm sure one of the proper leccies will advice you further. I'd hate to give you a bump steer!

You may have to rearrange the fuses on the busbar in descending 'amp' rating from the incomer, fuse rating, cable size etc... I won't even mention diversity - I thought that it was some new higher learning establishment!

Personally, I would just get a few quotes!

Hope that helps.

 

[mildmanneredjanitor]

Sorry Plugwash

by the time I'd finished typing, you must have replied!

Must learn to type f a s t e r !

 

[plugwash]

generally the only way to isolate power to the fusebox is to pull the service fuse (breaking the sleals on it) most recs don't care if this happens once or twice on a property but may get suspicious if it happens a lot

the incomeing cable conenctions to the cu should be seperately covered inside the cu (or in moer moden cus have the screws down deep finger proof holes so it should be safe in there with the main switch off and the lid removed nonetheless however you should still take great care the first time you open it in case the incomer cover is missing

i think the most sensible option if you are not eletrically confident enough to do a cu replacement is to put in the cooker cuircuit but don't conenct it

then call a sparky and tell him you wan't your cu replaceing with a mk split load one with plenty of space spare

 

[mildmanneredjanitor]

generally the only way to isolate power to the fusebox is to pull the service fuse (breaking the sleals on it) most recs don't care if this happens once or twice on a property but may get suspicious if it happens a lot

I thought breaking seals was illegal???

Last time I did, I was severely repremanded by IFAW!

Or was that for a blowing a seal...

'No, honestly it's just frost on my upper lip!'

 

[plugwash]

technically you are not mean to break them

in practice sparkys do it all the time and the recs don't care
generally if they notice at all they just say to the householder had some work done hace you (or words to the effect) and replace the seals

 

[mildmanneredjanitor]

I believe that the idea of a 'user' not being able to completely isolate a fusebox is absurd and flawed. But I suppose it prevents many people from carrying out their own work.

I suppose this may be the logic?

Be interesting to see if there are any tag crimpers on ebay!

 

[securespark]

Ask nicely, some recs may charge, but you can fit a 100A DP switch upstream of the CU.

If you ever do break a seal (not advocating it) you should ask the rec for a completion cert and fill it out and then make an appointment for them to reseal. They do not charge, unlike an angry rhino.

Well, MMJ mentioned seals, although to admit that in public takes b*lls....

 

[dingbat]

If you ever do break a seal (not advocating it) you should ask the rec for a completion cert and fill it out and then make an appointment for them to reseal. They do not charge...

EME charge about £23 for a call out to either cut or replace seals, or about £30 if they cut and replace on the same visit. But as the majority of installations I see are due for an update I usually get the householder to ask for a fuse and tail upgrade with an isolator, which they will generally do for free. (If your meter needs upgrading the isolator may well be built into the new meter.)

 

[mildmanneredjanitor]

That reminds me, haven't been out clubbing for ages...

 

[Big_Spark]

Hey MMJ, that diet is working mate, your looking a lot slimmer than a few weeks ago

 

[mildmanneredjanitor]

Hey MMJ, that diet is working mate, your looking a lot slimmer than a few weeks ago

I'm not fat, just vertically challenged!