wiring shed

[robcatty]

Thank you PrenticeBoyDerry, The main consumer unit has a 0.03amp ( which I take to be 30 milli amps) protection on it. I intenr to use 2.5 armoured cable overground which will be clipped to the garage wall at a height of 7 or 8 feet and will see no traffic underneath, either by foot or any other means. Again thanks so much one and all for your input.

 

[PrenticeBoyofDerry]

I would reconsider by design the CSA of your SWA, 2.5mm my well not be adequate once load and voltage drop are taken in to consideration.
But this would need calculating and also the existing device size and existing distribution cable CSA from house to garage to obtained.
It could be that 4.00mm could be better suited, providing the cable is securely fixed to walls along it's route, using the recommended clipping distance, your proposed project seems fine with regards to routing of cable.
As the distribution cable is SWA, it does not require RCD protection as it is mechanically protected. Often it is best to omit RCD at distribution side from CU and then introduce it at the Garage/Shed CU. This would help prevent any nuisance trips to the power and lighting circuits within the house caused by external/out building circuits and equipment.

If your intention is still to extend circuit from garage, a little further investigation would be required in to the distribution side from main house CU. (cable and device size are important) Normal procedure would be to calculate load then work out fuse rating and cable size. But in this instance it maybe that you are restricted by what is existing, to what load can be safely applied.

 

[robcatty]

Thank you so much again for your advice, I will certainly take on board what you say. One question you could poss answer: To calculate amperage of an electrical apparatus, say a washing machine, I believe this to be: Wattage/ Voltage. EG 2400/240 giving 10 amps drawn. Am I correct? Sorry to be a pain. Thanks yet again.

 

[EFLImpudence]

Yes that is correct for simple resistive loads - like heating elements.

 

[robcatty]

Thanks again.The existing feed to garage is from a 32A breaker on my consumer unit using 4 mm Armoured cable. There is then a 2 way CU with a 30A and 5A in garage from which is run 1 single and 1 double socket and 3 lights. It is my intention to then continue this run to shed using 4mm armoured as already used and fit 2 double sockets and tap off for 2 strip lights. The reason that I asked how to derive amperage is because the existing setup has my kitchen on a 32A breaker running cooker, dishwasher , microwave and kettle, all of which, using the formula stated amount to 24.6A drawn. Then a large fridge freezer which I don't know the rating of. I guess about 2000 Watts?. That being the case it exceeds 32A. On top of that the electrician who did work for me a few years ago has 'doubled up' and put the garage supply onto the same breaker and as I already said there is a washer and a drier in there which I guess draw 12A minimum each, although we don't run both at same time. The potential is therefore there to draw 60A. Am I paranoid or am I correct? If correct I will split the two off because there is spare capacity in the CU. I know I'm going on somewhat but I of course want to get safety first. Thanks so very much yet again and I promise you will soon be rid of me.

 

[riveralt]

Thanks again.The existing feed to garage is from a 32A breaker on my consumer unit using 4 mm Armoured cable. There is then a 2 way CU with a 30A and 5A in garage from which is run 1 single and 1 double socket and 3 lights. It is my intention to then continue this run to shed using 4mm armoured as already used and fit 2 double sockets and tap off for 2 strip lights. The reason that I asked how to derive amperage is because the existing setup has my kitchen on a 32A breaker running cooker, dishwasher , microwave and kettle, all of which, using the formula stated amount to 24.6A drawn. Then a large fridge freezer which I don't know the rating of. I guess about 2000 Watts?. That being the case it exceeds 32A. On top of that the electrician who did work for me a few years ago has 'doubled up' and put the garage supply onto the same breaker and as I already said there is a washer and a drier in there which I guess draw 12A minimum each, although we don't run both at same time. The potential is therefore there to draw 60A. Am I paranoid or am I correct? If correct I will split the two off because there is spare capacity in the CU. I know I'm going on somewhat but I of course want to get safety first. Thanks so very much yet again and I promise you will soon be rid of me.

And Breathe!!!!! And Paragraph!!!!!!

 

[JohnW2]

On top of that the electrician who did work for me a few years ago has 'doubled up' and put the garage supply onto the same breaker [as the kitchen supply]...

That seems rather bizarre and unnecessary, given that...

...If correct I will split the two off because there is spare capacity in the CU.

It certainly would be desirable for the kitchen and garage to be (and to always have been) on separate MCBs.

However, whilst extending the garage circuit into the shed would probably be 'non-notifiable', some might argue that shifting the garage (and shed) supply onto a new breaker constituted creating 'a new circuit', which would make it notifiable work. That does seem/feel a little odd to me, so I'd be interested to hear what others think.

Kind Regards, John

 

[riveralt]

Thanks again.The existing feed to garage is from a 32A breaker on my consumer unit using 4 mm Armoured cable. There is then a 2 way CU with a 30A and 5A in garage from which is run 1 single and 1 double socket and 3 lights.

It is my intention to then continue this run to shed using 4mm armoured as already used and fit 2 double sockets and tap off for 2 strip lights.

Are you going to have a garage unit in the shed? How do you intend to connect things if not.

The reason that I asked how to derive amperage is because the existing setup has my kitchen on a 32A breaker running cooker, dishwasher , microwave and kettle, all of which, using the formula stated amount to 24.6A drawn.
Then a large fridge freezer which I don't know the rating of. I guess about 2000 Watts?. That being the case it exceeds 32A.

As long as the ring (assuming it is a ring final circuit) is balanced it shouldn't be a problem - Diversity will apply for some of the appliances and common sense for the others.

On top of that the electrician who did work for me a few years ago has 'doubled up' and put the garage supply onto the same breaker and as I already said there is a washer and a drier in there which I guess draw 12A minimum each, although we don't run both at same time.

Okay you lost me here. Are you saying that the garage supply is using the same 32Amp MCB as the Kitchen?
If so not good - and not good to add any more load to this single circuit.

The potential is therefore there to draw 60A. Am I paranoid or am I correct?

Both!!!

If correct I will split the two off because there is spare capacity in the CU. I know I'm going on somewhat but I of course want to get safety first. Thanks so very much yet again and I promise you will soon be rid of me.

Which is something I think you will have to do - and this will be notifiable.

 

[EFLImpudence]

Thanks again.The existing feed to garage is from a 32A breaker on my consumer unit using 4 mm Armoured cable. There is then a 2 way CU with a 30A and 5A in garage from which is run 1 single and 1 double socket and 3 lights.

You don't really need the 30A in the garage.
If I have read correctly and everything is protected by the same RCD. that is not ideal.

It is my intention to then continue this run to shed using 4mm armoured as already used and fit 2 double sockets and tap off for 2 strip lights.

You could connect it to the supply side (i.e.the incoming SWA (armour).

The reason that I asked how to derive amperage is because the existing setup has my kitchen on a 32A breaker running cooker, dishwasher , microwave and kettle, all of which, using the formula stated amount to 24.6A drawn. Then a large fridge freezer which I don't know the rating of. I guess about 2000 Watts?. That being the case it exceeds 32A.

They won't all be on at once.
Fridges don't use much.

On top of that the electrician who did work for me a few years ago has 'doubled up' and put the garage supply onto the same breaker and as

That's not a good idea.

I already said there is a washer and a drier in there which I guess draw 12A minimum each, although we don't run both at same time. The potential is therefore there to draw 60A.

That won't be a problem when on a different MCB and, as said, everything is not on at once.

Am I paranoid or am I correct? If correct I will split the two off because there is spare capacity in the CU.

Yes, do that.

I know I'm going on somewhat but I of course want to get safety first.

Quite but there is more to safety than just the actual electric side.

For instance all the circuits on the same RCD could switch off because a bulb in the shed has blown and plunge you into darkness while doing something hazardous in the house.

There are a number of things you could do to alleviate this but an internet forum is not really the place.

You really do need another electrician on site and that will save the LA fee.

 

[robcatty]

Yes, rather odd both kitchen and garage are on same breaker considering the spare capacity in CU. They were separate on the old wire fused unit up till two 'electricians' wired my downstairs power and light circuits., leaving behind other issues too numerous to bore everyone on this site with.
They wired a new 10 way CU into my property and I suspect did the job as conveniently as poss for themselves and without the fuss of supplying a new 32A breaker
I will split off and put garage on non protected side of panel and then seek out another electrician to continue and to protect at garage side. It seems more trouble than it's worth if I have to notify LA , and of course I assume I will need it to be certified as well.
Thanks to all.

 

[JohnW2]

I will split off and put garage on non protected side of panel and then seek out another electrician to continue and to protect at garage side. It seems more trouble than it's worth if I have to notify LA ...

I would have thought that it would make sense to get the electrician to do that 'splitting off' as well.

Kind Regards, John

 

[ericmark]

It certainly would be desirable for the kitchen and garage to be (and to always have been) on separate MCBs.

However, whilst extending the garage circuit into the shed would probably be 'non-notifiable', some might argue that shifting the garage (and shed) supply onto a new breaker constituted creating 'a new circuit', which would make it notifiable work. That does seem/feel a little odd to me, so I'd be interested to hear what others think.

Kind Regards, John

This comes back to the post on what is a circuit and although as you say some would consider it as being a new circuit and for a scheme member electrician likely he would play safe and consider as a new circuit.

For some one who has to pay £200 plus if they think it's a new circuit I would consider it was an existing circuit and not pay the LABC.

What has to be considered is what happens if some one disagrees with one and tries to say it is a new circuit? The only time when it will come up for scrutiny is if:-
A) Something goes drastically wrong. i.e. a death as a result of workmanship.
B) Selling the property where the solicitor requests the installation certificate and completion or compliance certificate.

Wording may make all the difference. Moving part of the circuit to its own dedicated MCB may mean the same as splitting the circuit into two but a solicitor may consider the latter as new circuit and former as existing circuits. Clearly Minor Works not Installation Certificate should be filled in as filling in an Installation Certificate would show it as being new circuit.

However I would question if most DIY people could fill in a minor works certificate best one could ask for is and Electrical Installation Condition Report when the house is sold.

 

[JohnW2]

What has to be considered is what happens if some one disagrees with one and tries to say it is a new circuit? The only time when it will come up for scrutiny is if:-
A) Something goes drastically wrong. i.e. a death as a result of workmanship.
B) Selling the property where the solicitor requests the installation certificate and completion or compliance certificate.
Wording may make all the difference. Moving part of the circuit to its own dedicated MCB may mean the same as splitting the circuit into two but a solicitor may consider the latter as new circuit and former as existing circuits.

No-one is going to argue with (A). As for (B), as I often say, I think people get too excited about this, assuming they are not being dishonest. It would seem very unlikely that a solicitor would express an opinion as to what constitutes a 'new circuit' and, even if (s)he did, their 'lay' view could easily be challenged, given that even electricians cannot agree on the answer. If the seller simply indicates that it was DIY work which was not notified because it was not consdiered to be a 'new circuit', then I very much doubt that there would be any problems. If a buyer wants to know about the state/safety of the electrical installation, they should commission an EICR, just as they would a structural survey - even if immaculate paperwork were in place, the installation could still be unsafe!

I have already hinted at an approach which we can/should not really discuss here, but which would you most suspect was the subsequent work of a DIYer (rather than the work of an electrician who originally installed the circuits) - a kitchen and garage circuit both fed from the same MCB, or each circuit having its own MCB?

In any event, as I've just written, if the OP is going to use an electrician anyway, he might just as well get that electrician to 'regularise the MCB situation'.

Kind Regards, John

 

[robcatty]

Thanks all. Yes I feel now that I would be best to employ someone rather than get what may be hassle later. I always prefer the DIY route, espescially given the probs caused by the electricians who worked for me before, but I also don't want an unsafe and poss problematic installation for the maybe £300 cost.
Thanks finally to all.