Electric to outdoor utility room

[trojanhawrs]

How difficult would it be to do things properly and run a new circuit from your main CU?
Is your utility room completely separate from the house?

 

[securespark]

It's not an assumption. It's based on what he said he was doing and based on that I advised limiting the load on that cable to 13A.

 

[JohnW2]

It's not an assumption. It's based on what he said he was doing and based on that

I presume that is a response to comments I made earlier.

When I made those comments, all the OP had told us was that he proposed to use 2.5mm cable - and to extrapolate from that to the fact that he intended to include an FCU was surely not only 'an assumption', but I somewhat unwise one (given that questions the OP is asking suggest that he might not have realised the need for an FCU).

I advised limiting the load on that cable to 13A.

I would personally not call what you said 'advising'. Rather, you assumed (at a time when this hadn't been mentioned) that the proposed cable size meant that it would be a fused spur and, based on that assumption, made the statement ....

I would not bother with a CU. You are limited to 13A anyway,...

However, none of that matters any more, since the OP has subsequently, after I made my comment, said that he would be "happy to come out of the ring in the house into a FCU" - but we still don't know whether or not that was his original intention/proposal

 

[briwire]

If you are taking a spur off the ring main, you would need to go through a 13amp spur unit, so your load would have to be limited to 13amp. 2.5mm will do for that unless the distance is great enough to bring volt drop into it.
It's quite possible that 3 of the 4 could be consuming current.
On a side issue, I know from experience that you will need a small heater for your washer and an old quilt to throw over it in cold weather.

 

[Jupiter01]

given that questions the OP is asking suggest that he might not have realised the need for an FCU).

I didn’t…

 

[Jupiter01]

How difficult would it be to do things properly and run a new circuit from your main CU?
Is your utility room completely separate from the house?

This would indeed be quite difficult. The CU is in the centre of the house and it will mean considerable upheaval to thread a cable through the house.

On the subject of a separate Consumer Unit on the utility room, wouldn’t this be beneficial from an isolation point of view? It could have 3 ways: sockets, internal lighting and outdoor lighting. If the outdoor lights developed a fault, would it trip at this CU? Also, if I am doing work on one of these 3 circuits, I can isolate that individual circuit. Might be flogging a dead horse but thought it would make for a neater install.

 

[trojanhawrs]

On the subject of a separate Consumer Unit on the utility room, wouldn’t this be beneficial from an isolation point of view? It could have 3 ways: sockets, internal lighting and outdoor lighting. If the outdoor lights developed a fault, would it trip at this CU? Also, if I am doing work on one of these 3 circuits, I can isolate that individual circuit. Might be flogging a dead horse but thought it would make for a neater install.

It's not neater, it's just more stuff on the wall. Realistically what you want is a double socket or 2 and a switched fused spur for your lights. The most likely common faults with outdoor lights are caused by water ingress which will trip the RCD at your main CU anyway.
A better option than spurring would be to extend the ring, I'll ask again though is the utility room a part of the house? I noticed you mentioned running a cable outside to it.

 

[JohnW2]

I didn’t…

Does that mean that, from the very start, the spur you have been talking about was always going to be a 'fused' one (i.e. supplied via an FCU), hence with a maximum 'permissible' total load of 13A ?

 

[JohnW2]

On the subject of a separate Consumer Unit on the utility room, wouldn’t this be beneficial from an isolation point of view? It could have 3 ways: sockets, internal lighting and outdoor lighting. If the outdoor lights developed a fault, would it trip at this CU? Also, if I am doing work on one of these 3 circuits, I can isolate that individual circuit. Might be flogging a dead horse but thought it would make for a neater install.

There would be no harm in installing a small CU if you really wanted to (although some might argue that it would then become notifiable work, even though you were not literally 'replacing' a CU), but it would serve little purpose.

If there were a CU and if, as it has been discussed, it was fed via a 13A FCU, then the protective devices in the CU would not really achieve anything.
Furthermore, attempting to 'isolate' the outside lighting circuit if it were suffering from water ingress by switching off a standard (single-pole) MCB in the CU would not prevent an upstream RCD (in the house) tripping if there were a N-E fault on that circuit - so that, even if you had a CU you would be advised to also have a double-pole switch on that circuit (which would make the CU even more redundant).

If you really wanted to be able to isolate the sockets and interior lighting circuits individually and 'locally' if/when you wanted "to work on those circuits", that could also just be done with switches (but how often are you likely to want to work on those circuits?!)