Advice needed on new home wiring

johnmah

Hi Guys,

First thread but have been around for awhile.

I am about to wire my own home (new semi-d) and looking for advice on the regulation side of things.

I am wondering what needs to done regarding the meterbox. There is a 16sq t+e from the meterbox into the house when been built but I seen that there is something in the regs regarding a MCB in the meterbox?

Regarding the bathrooms, whats allowed in regarding lighting, zones, protection etc? Ive picked out IP65 spot lights for the main and en-suite.

Are ring circuits still allowed regarding sockets?

Im thinking of running a 6sq t+e upstairs into the hot press for a sub board so I dont have to run everything back downstairs. Good or bad idea?

Im including plenty of sockets, tv and phone points throughout the house. Running all heating/stats etc back to the hot press,

All help and advice would be greatly apprecited as I haven wired a house in years as been in away.

Thanks in advance

M cebee

mcb for meter tails in cabinet-prob isolator in consumer unit


bathroom rcd for lights i think

no rings in kitchen

off top of my head i think DBs not allowed in hot press

johnmah

cheers for the quick reply


By "mcb for meter tails in cabinet-prob isolator in consumer unit" is that connected to the ESB side or the consumer side i.e replacing the esb fuse in the meterbox

Prob move the DB to one of the bedrooms just to avoid problems with RECI.

maxamillius

board is not allowed in hotpress,

i thought rings were not allowed anywhere anymore could be wrong though??!

M cebee

would be

esb cutout-meter-mcb in that order

maxamillius

why is it there not allowed in kitchen?

M cebee

jeez what was the reason again

maybe either the number of spurs/unfused spurs being added on later

else maybe the high risk of overcurrent if the ring breaks in kitchen

i could be missing the obvious - i heard the reasoning before

maxamillius

ah ye they seem like good enough reasons to me,would you still install rings elsewhere? do many still do it do they?just seem like best practice to keep to radials even though there not without fault either!

M cebee

i prefer rings -no unfused spurs

and some radials

meercat

If you can get a house sparks to help you on the first fix it may save you hastle in the long term.
Bathroom circuits need rcd protection
ring circuits are allowed (but not in kitchens)
sub board is bad idea(no wiring allowed in hot press,not even immersion switch)
heat detector kitchen, smokes hall landing livingroom
switch heights max1.2 metres
distribution board ,to top max 2.25 metres

Bruthal

M cebee wrote: »

jeez what was the reason again

maybe either the number of spurs/unfused spurs being added on later

else maybe the high risk of overcurrent if the ring breaks in kitchen

i could be missing the obvious - i heard the reasoning before

Here`s a couple i can think of at the moment

Break in ring goes un-noticed, so a radial circuit self monitors better,
If there is a break in the ring now we have in effect 2 radial circuits of 2.5 but a 32amp breaker supplying both
If earth is open in ring then the earth is now too small on each side for the 32amp circuit,

I never really seen much advantage in ring circuits. Radials probably need bit more planning in kitchen areas but one ring into kitchen is like 2 radials with one link removed, just an extra MCB so the need for ring circuits is non existant really.

M cebee

the higher capacity on domestic rings isn't needed really with the kitchen rings barred

but they're still handy for VD and Zl on the longer runs even if they were derated down to 20amp


and of course they can be split if a t+e gets damaged

Bruthal

M cebee wrote: »

the higher capacity on domestic rings isn't needed really with the kitchen rings barred

but they're still handy for VD and Zl on the longer runs even if they were derated down to 20amp


and of course they can be split if a t+e gets damaged

True but the damaged t&e could go un-noticed. Even if breakers trip, a fella after drilling through it will reset and it might well stay on, and all sockets still working, so no damage done "apparently".

I never liked the idea of ring mains myself from day one and said before on boards that im surprised with all the regulations out now that they were still allowed.

De rating down to 20 amp would eliminate some of the bad points alright. And keep the VD and loop better.

M cebee

for big work as well-they're an efficient way of delivering power

large ring main instead of smaller radial sub-mains depending on the application

johnmah

Hi guys

An update to see if everything that Ive done is ok.

4-5 double sockets per circuit.
2 circuits in the Kitchen for sockets.
10 Sq Earth in the hot press for bonding and also under the sink
All heating stats wired in PVC Brown Brown and all heating ran back to central point.
Smoke and Heat Det, wired in 1.5 T&E with a 1.5 Pvc Brown linked around
Two Cat 5E and 4 Tv Points to every point.
Bathroom llighting circuits on seperate circuits and fans isolated

Alarm yo every window and door downstairs and PIR on other two floors.

M cebee

you dont need a main bond for sink

i wouldv'e ran 5-core for stats but twin will work

johnmah

cheers

Why would ya need 5 core for the stats?

Regarding the bonding I wasn too sure so ran it to be covered

M cebee

supply + contact = 5-core usually safer

usually run a 5*.75

you can fire the boiler via mvs or close a relay for volt-free contact

maxamillius

agree with m ceebee 5*.75 from manifolds to stats thats the way the last underfloor heating job i did was wired,as m ceebee stated usually a wiring diagram is supplied as systems can differ!

johnmah

Just a quick question.

In the ESB cabinet what do I need to put in?

Do the ESB will bring their cable in straight to the meter and then to Isolator where I connect my tails or have I heard somewhere that I have to put an 80A fuse after the Isolator and then connect the tails from the consumer board to this MCB.

Thanks lads

M cebee

cut-out>meter>mcb

and prob just 'main isolating switch' in the consumer unit then

it's in the wiring rules

Davy

They will pull in the cable, then a cut out bottom left, meter on top of it, and then probably mount an isolator beside it. With the new meters their isnt a built in isolater so they will mount one to the rightof the meter.

So just have the duct finished to bottom left hole, rope in it, and then your tails ready on the left.

ricman

so is where does the timer unit,or switch go for the immersion cylinder, in the kitchen , or front room?

M cebee

outside within 2metre for switch


the timer can go anywhere

does anyone here have a copy of the wiring rules:pac:

i usually find i'm not complying with the rules -if i don't check them

that's what they're there for-to save us gombeens trying to figure out what's right

sparcocars

johnmah wrote: »

Hi guys

An update to see if everything that Ive done is ok.

4-5 double sockets per circuit.
2 circuits in the Kitchen for sockets.
10 Sq Earth in the hot press for bonding and also under the sink

2 ring circuits : 1 for downstairs(excluding kitchen)
1 for upstairs.
Ring circuits can have an unlimited amount of sockets as long as the area they cover is not more than 100m squared. So a regular sized house would be okay. These circuits to be protected by 1 32 amp b-type mcb each.

2 radial circuits for kitchen protected by 1 20 amp mcb each. A radial circuit is limited to 10 double sockets.

All sockets to be done in 2.5 T&E.
2.5 T&E for immersion.
All the above protected by an RCD also.
10 square is only for the main bonding (to earth rod, main gas incomer and main water incomer if its copper)
2.5 square is okay for local bonding of pipes in house.

M cebee

metallic services(water) within the building need a main bond