Electric meter - meter tails etc etc..

[No skills]

A while ago I posted up about sorting out the electric supply that currently feeds the garage/workshop, some folks here were very helpful with some advise (thanks again). I couldn't face digging up the armoured cable and trying to find the buggered bit (100 foot or so) so I've left it till now and for the sake of £100 odd of cable I'll put a new run in that I know is good.

First things first though, the supply is fed from a 32a mcb that's on the rcd side of the household consumer unit - I want to change this so there's a separate mini consumer unit for the garage feed - as a bonus this will give me a spare slot in the main cu for adding another circuit come kitchen renovation time.

So I need a mini cu and a set of tails, no problem. Connecting the tails... Hmm...
After the main service fuse is the meter and then tails to a Henley block/connector then tails to the house cu. I understand that the meter is the electric suppliers property but what about the Henley block after that?
Could an electrician connect new tails to the Henley block without any permission from the suppliers?

A small detail.. The meter is of a key type (house is ex-rental), which I've never bothered to get changed. I spose when the meter runs out of credit the Henley block is no longer live..

Any thoughts folks?

 

[n0legs]

A competent person can connect into the Henley blocks on the consumer side of a meter without the permission of the electricity supplier or DNO.
The size of the meter tails and their future loading is something to be considered. Identification of the new tails, via the correct colour tape or other form of identifier should also be considered, but a good electrician should be up to speed with all of that.
The Henley blocks will be "dead" when the credit has run out on the meter.
Waiting for the meter to run down is an option but polarity checks can be a problem on a dead supply.

 

[Myfordman]

AFAIK you can connect to the henley block and you should change the meter as this must be putting you on a poor tariff. When the current credit runs out you will lose power.

 

[Phil Pascoe]

Any prepayment meter will cost you seriously.

 

[n0legs]

Just do away with the meter, it'll work fine without it :lol:

 

[No skills]

Ok, Henley block connection is ok - make sure new tails are marked and don't get the live and neutral mixed up

Length of new tails is approx 500mm feeding a 40a rcd so I was thinking 16mm rather than 25mm tails.

I'll make sure the err electrican is prepared.

Thanks all.

 

[mindthatwhatouch]

What size is the main fuse?
This protects the tails so these should be sized accordingly.
25mm tails with a 16mm earth is pretty much standard these days, sounds like you may as well upgrade the consumer unit whilst you are at it.

 

[OLD]

Just keep the existing arrangement then extend the ring main, cooker and the lighting circuits when you renovate the kitchen.

 

[No skills]

Right o garage cu and tails purchased from poofix, they have a 'BG' garage cu for £15 at the moment - I've used a couple of them before at work and the quality seems ok.

The current household cu is fine really, the current mcb space that is used for the garage is destined to be a new cooker feed for the kitchen revamp - I will be adding a second oven in the kitchen and the current arrangement isn't up to it. Also I don't want garage feed problems tripping out the house rcd.

I could move the garage mcb over to the non-rcd side of the board as I have a spare way but I'm not comfortable having all that live cable in the garden without rcd protection.

Thanks for the thoughts

 

[colinc]

Hi,

I am not a qualified electrician, but the plan mine has for the workshop (if he ever gets around to it) is subtlely different to what you describe. I thought it makes sense the way it is going to work.

First, I just had a man from NPower turn up and he fitted an isolator between the meter and the CU. This is a free service for NPower customers so take advantage if you buy from them or check with your supplier. Now the supply can be isolated simply and safely.

As described the supply will be split after the isolator into a henley block. The workshop feed will go to a new switch box which contains an isolator and a specialised RCD which needs a higher current to trigger than the normal ones. That protects the armoured cable. The workshop consumer unit is in the workshop (waiting patiently) and that has various circuits.

The idea is that a fault in the workshop will not trigger the RCD at the house end, instead the more sensitive devices at the workshop end react first. The fact that the house end rcd is a different standard means that the cable has to be armoured or in conduit in the house, so in my case the armoured cable runs all the way to the house CU cupboard. What it does mean though is that if say the workshop ring main is tripped, the lights stay on. The way you desrcibe it, it will be pretty random what blows.

Another little twist is that at 50m it was felt neccesary to install earth rod(s) at the wokshop end so the armoured cable sheath is not connected to the workshop, it stops where the cable is terminated.

Hope that's useful.

Regards,

Colin

 

[No skills]

Sounds like you are having a 100ma trip rcd at the house end, a good idea. It is quite correct that both the garage rcd and the garage feed rcd (once installed, not done it yet) could both trip in my situation as both of the Rcds are 30ma, this is something I'm happy to live with (I have a similar situation at work, but that's another story) - the main point of this is to stop the garage tripping the house in the case of a fault.

Interesting to know some suppliers will do the isolator install for free.

Thanks.

 

[RogerS]

.....What it does mean though is that if say the workshop ring main is tripped, the lights stay on. .

Do you mean the house lights or the workshop lights?

Another little twist is that at 50m it was felt neccesary to install earth rod(s) at the wokshop end so the armoured cable sheath is not connected to the workshop, it stops where the cable is terminated.
....
Colin

Does that mean that you have no earth in your workshop wiring?

 

[colinc]

Hi,

Yes, the worshop has individual breakers for different circuits, i.e. inside and outside lights, 13a sockets, 16a sockets etc. if a socket RCD trips the workshop lights stay on. Nothing in the workshop affects the house.

The earth rods at the workshop end provide the earth connected to the Workshop CU, it doesn't rely on exporting the house earth over that distance, although the house earth does protect the armoured cable to the workshop.

I checked and the parts at the house end include a 100ma breaker.

Hopefully that clarifies it?

Regards,

Colin

 

[RogerS]

Yes, it does, thanks, Colin and if I was redoing my workshop then I'd do something similar.

As it is, I have a CU protected by a single RCD and individual breakers. I occasionally get a trip fault on start-up on my drum sander and it takes out the breaker which kills everything in the workshop including the lights. More annoyingly the CU is elsewhere in a locked up part in the third bay and stores all SWMBO's gardening stuff. But it's right in the far corner and so without lights a right old How's Yer Father to clamber over all her stuff just so I can reset the RCD! :?

I'll be getting one of those emergency torches that automatically come on when there is a power cut. Very handy when you get a cut and the table saw sharp spinny thing is whizzing around!

 

[bussy]

Hi,


First, I just had a man from NPower turn up and he fitted an isolator between the meter and the CU. This is a free service for NPower customers so take advantage if you buy from them or check with your supplier. Now the supply can be isolated simply and safely.

Regards,

Colin

Hi
You must have been lucky because isolators from Npower are definitely not free, can't remember the exact cost but it is over £100, think it's around £130.

Marty

 

[colinc]

Hi,

Not lucky, the deal is that Meterplus do the work, but if you buy your electricity from NPower then they do it for free. Otherwise it's about £131

Call them if you are an NPower customer before they change their policy.

Regards

Colin

 

[bussy]

Hi Colin
Meterplus is Npower, it's just the vans haven't been re-branded yet. The guy that fitted your isolator should have been wearing an Npower uniform and ID. It may be different in your part of the country but up here everybody pays Npower customer or not. As it happens I work for Meterplus/Npower installations.

Marty

 

[colinc]

Hi Marty,

I did know the connection between the two organisations but the lady was very clear about no charge for it.

It would be interesting to see if any other NPower customer wants to give them a call and see what they say?

Regards,

Colin

 

[bussy]

Hi Colin
I stand corrected, as you say they are free to Npower customers. It's bad crack when the employees aren't aware of things like this.
Marty

 

[colinc]

Hi,

The guy who fitted mine didn't know either but after I told him he was booking to have his own done!

Communications don't seem To be MeterPlus's forte all of the time, it took 4 or 5 visits to fit a new gas meter as they kept turning up without suitably large earth clamps, one guy turned on several occasions just to apologise for not having them again!

Still, no one's perfect!

What I need now is an electrician to finish the workshop wiring, mine seems to have emigrated! Is there anyone here qualified and willing to do the job?

Regards,

Colin