Looking for a large (wide) Amd 3 CU

[Iggifer]

Seems reasonable enough, but:

You don't need a dedicated circuit for the dryer
Just put all outside lights on one circuit, unless there's a valid reason you don't want to
You could also just put the outside sockets on one circuit too.

 

[Doggit]

I assume the sockets front and rear are for using outside equipment, and if so, there's nothing wrong in running a switched spur from the ring mains, as the CU's RCD is going to cut in anyway. I'd first run a separate circuit for the kitchen, and then the dryer and freezer and boiler would also be switched fused spurs coming off the kitchen ring main. The external lights both front and rear should be leds nowadays, so unless you're using something more powerful, these too could be switched fused spurs off the ring circuit - or possibly the lighting circuit - but I'd be interested to get others opinions on this. If you are determined to use an MCB, then both front and rear external sockets can go on the same switch, as can both the external lights.

The burglar alarm can also be a switched fused spur off of the cellar ring, as can the cctv system.

Although you've said you're using a paneled fire alarm, I can't see why you don't use a mains interlinked set of smoke and heat detectors with an isolating switch; this switches of all the detectors when pushed, except the one that set the system off. But I'd put this on a separate circuit to stop any interference from other circuits hiccuping.

 

[Doggit]

With the recent controversy over tumble dryers and washing machine catching fire, it turns out that manufactures have already been stating in the instructions they should be switched off when not in use, hence part of the reason for having a switched spur on the wall above the appliance. But who reads instruction manuals.

 

[newconnection]

Thanks, the suggestions make sense so i've updated the circuit arrangement as follows:

Note: The property may be used as HMO or a family home (TBD) - my understanding is that this requires mains interlinked smoke alarms with a heat detector in the kitchen and a panel in a communal area to help identify where the fire is - i.e. zone. Are you suggesting that a panel isn't required?

1. Sockets - cellar - including fused spurs for burglar alarm and CCTV.
2. Sockets - ground - including fused spurs for front and rear external sockets.
3. Sockets - kitchen - including fused spurs for boiler, washing machine and tumble drier
4. Sockets - first floor
5. Sockets - second floor
6. Lights - cellar
7. Lights - ground - including kitchen and front and rear external lights - should the external lights be on a ring main instead?
8. Lights - first floor
9. Lights - second floor
10. Shower
11. Fire/smoke alarm
12. Utility - freezer and/or dryer - fused spurs? What about preventing the freezer defrosting?
13-18 Spare

 

[Iggifer]

I'd definitely have a dedicated circuit for outside stuff, you just don't need two of each.

What do you mean re: freezer defrosting? I'd also have a dedicated circuit for the boiler/CH. I assume you're going all RCBO?

 

[JohnW2]

I'd prefer to keep to one CU if I can.

Fair enough, but I must say I would not have attempted that in my house - apart from anything else, some of the final circuits would have been very long!

Having integrated the cellar with burglar alarm and cctv, I was thinking of:

A few thoughts ...
Do you really need separate front/rear circuits for both external lights and external sockets?
Indeed, do you really need external lights circuits at all - could they not be taken of the external sockets circuit(s)?
Could you not have just one lighting circuit (and maybe even sockets circuit, given that only bedrooms are being supplied) for the two upper floors?
Couldn't the cellar lights come from either one of the other lighting circuits, or even the cellar sockets circuit?

Edit: I had somehow missed a number of posts when I wrote this one, particularly the revised list of the circuits and the mention of possible use as an HMO. Everything I wrote here was on the assumption that it was to be used as a family home. As has been said, use as an HMO would put the exercise into a whole different ballpark.

Kind Regards, John

 

[Doggit]

Using it as an HMO is another ball game altogether, and you'd need to talk to your local council to check the regs. You'll definitely need a panel, and a heat detector in each room, and a smoke detector on each floor - and loads of no smoking signs. Without seeing the property, it's difficult to determine whether you're better off with a CU on each floor, or in the basement. If one tenant sets off the RCD, then everyone suffers, so a bit of isolation on each floor might be a better way to go. It also depends on whether you make a service charge for their electricity, or put a coin meter in each room, which then means that you've got to have a CU in each room as well.

As a home, there's only one owner, but in an HMO, you need to separate communal areas from living areas, so external lights and sockets and internal hall lights would be communal, and each floor or room would then have their own CU.

You need to decide on it's use, and check on the councils requirements before you go much further.

 

[newconnection]

I mean if it's a separate freezer to prevent it tripping and defrosting?
What are the advantages of going RCBO?

1. Sockets - cellar - including fused spurs for burglar alarm and CCTV.
2. Sockets - external (front and rear) - including fused spur for external front and rear lights
3. Sockets - ground
4. Sockets - kitchen - including fused spurs for boiler, washing machine and tumble drier
5. Sockets - first floor
6. Sockets - second floor
7. Lights - cellar
8. Lights - ground - including kitchen
9. Lights - first floor
10. Lights - second floor
11. Shower
12. Fire/smoke alarm
13. Utility - freezer and/or dryer
14-16 Spare

 

[JohnW2]

What are the advantages of going RCBO?

With an RCBO protecting a circuit, it will not usually lose power due to a fault on another circuit. On the other hand, if several circuits (with just MCBs) are protected by the same RCD, then a fault on any of those circuits will 'take out' all of them.

Kind Regards, John

 

[ban-all-sheds]

What are the advantages of going RCBO?

It's worrying that you should have to ask a question like that if you are working as an electrician.

 

[ban-all-sheds]

Ah.

http://www.diynot.com/diy/threads/conversion-from-2-to-5-flats-water-connection-s.442142/

http://www.diynot.com/diy/threads/what-kind-of-incoming-electrical-connections-are-these.443785/

Why do I get the feeling that you have no intention of using an electrician?

 

[newconnection]

I'm not an electrician. I never said I was. I already have an electrician in doing one side (the flats). I am now doing my homework for the other side (the house) - and yes, I will of course consult/talk to the electrician.

 

[ban-all-sheds]

If you have an electrician, why are you deciding on the schedule of circuits?

If you have an electrician, why are you searching for and choosing the CU?

If you have an electrician, why are you making the decision between MCBs sharing an RCD and individual RCBOs?

 

[newconnection]

I am paying him labour only.

Often, contractors (including electricians) want to do things that are easier for them as opposed to being the best for me.

Without being rude, some of you are not the brightest sparks (no pun intended) so I like to be clued up as best as possible and as the proposed building manager, I think that's good practice too.

Hopefully this is clear enough for you so I'd be grateful for any relevant input but otherwise, please do not respond to my threads.

 

[ban-all-sheds]

I am paying him labour only.

And thereby paying more for materials that he would.

Often, contractors (including electricians) want to do things that are easier for them as opposed to being the best for me.

Not if they are any good.

But given your attitude I would not be surprised to learn that you can never find any good ones.

Hopefully this is clear enough for you.

Perfectly. Although not the clarity you wanted to achieve.