Getting power from one source to 2 wall sockets

EpiphoneSpecial

Hi All,

I have a bedroom with one set of cables coming into it.

I want to install 2 new wall sockets in the room.
Is a Terminal Junction Box the best way to split the power?
Like This One?

I'm guessing the function of this box is to take one source in and send 2 sources out?

Cheers

b318isp

You will have to loop them. See this picture:



AFAIK you can spur only one socket off a domestic ring main, but to get two you must loop.

EpiphoneSpecial

1. connect power source to junction box "in"
2. connect junction box to socket1
3. coonect socket1 and socket2 (plug 2 lives, 2 neutrals into each terminal?)
4. connect socket2 back into junction box

i'm a close?

brightspark

b318isp wrote: »

You will have to loop them. See this picture:



AFAIK you can spur only one socket off a domestic ring main, but to get two you must loop.

What makes you think he has a ring circuit?

Any spurs MUST be protected by an over current device (non-fused spurs are no longer allowed)

You used to be allowed the same number of spurs as outlets on a ring, the requirement to put in a fused spur outlet now means that it isn't really cost effective not to include most sockets within the ring.

brightspark

EpiphoneSpecial wrote: »

1. connect power source to junction box "in"
2. connect junction box to socket1
3. coonect socket1 and socket2 (plug 2 lives, 2 neutrals into each terminal?)
4. connect socket2 back into junction box

i'm a close?

Not sure you should be taking on this job. The junction box you linked to would be bad practice.

(Adding one outlet would be considered "minor works", but adding more is strictly speaking "controlled works")

2011

brightspark wrote: »

Not sure you should be taking on this job. The junction box you linked to would be bad practice.

(Adding one outlet would be considered "minor works", but adding more is strictly speaking "controlled works")

Agree on both counts.

Bruthal

brightspark wrote: »

Not sure you should be taking on this job. The junction box you linked to would be bad practice.

(Adding one outlet would be considered "minor works", but adding more is strictly speaking "controlled works")

Yea the worst junction boxes ever invented them yokes

Sir Arthur Daley

Bruthal wrote: »

Yea the worst junction boxes ever invented them yokes

+ 1 but the old school electricians might have different view on them

2011

Anyway, to assist you with your question.....

EpiphoneSpecial wrote: »

Hi All,

I have a bedroom with one set of cables coming into it.

By one set of cables do you mean two cables?

Generally sockets in a domestic installation are wired in 2.5mm sq. win & earth cable as shown in the picture below. Can you confirm that your cable is like this?

I want to install 2 new wall sockets in the room.
Is a Terminal Junction Box the best way to split the power?

No, although junction boxes are permitted it is generally considered bad practice to use one for a socket circuit.

Ideally the only joins on a socket circuit cable are at the sockets themselves.
Most electricians nowadays would say that is best to wire radial socket circuits such as this:



I am not a fan of ring socket circuits.

I'm guessing the function of this box is to take one source in and send 2 sources out?

It can be. But connecting 3 cables together in a single junction box can often be difficult as the terminals often only have enough space for two cables.

A few things to note:

1) A radial socket circuit should supply no more than 10 double socket outlets. You need to ensure that the addition of sockets will not push this circuit beyond this.

2) Typically a socket circuit in a domestic installation is supplied by a 20A B type MCB (but not always). You should identify what type MCB is protecting this circuit.

3) Socket circuits should also have supplementary protection from an RCD. Something this is achieved by installing an RCBO. You should ensure that your socket circuits are protected this way.

4) All connections should be throughly tightened.

5) The earth conductor should be sleeved with PVC green/yellow sleeving.

6) All additions to the installation should be properly tested as per the ETCI regulations.


I am hoping that this gives you a better insight.
My advice to you is to get a qualified electrician to do this work, preferably a registered electrical contractor.

Remember mains voltage can be lethal!

zega

Why do you reckon radial's are better than ring circuits?

brightspark

zega wrote: »

Why do you reckon radial's are better than ring circuits?

The problem with a ring circuit is it is if any point in the circuit breaks you effectively have a 2.5mm cable 'protected' by the 32A MCB :eek:
And there will be no indication of a break, i.e. all sockets work normally, if you had a break in a radial circuit the sockets beyond the fault won't work.

Sir Arthur Daley

brightspark wrote: »

The problem with a ring circuit is it is if any point in the circuit breaks you effectively have a 2.5mm cable 'protected' by the 32A MCB :eek:
And there will be no indication of a break, i.e. all sockets work normally, if you had a break in a radial circuit the sockets beyond the fault won't work.

Any time i used ring circuits i protected them via a 20 amp mcb.

zega

brightspark wrote: »

The problem with a ring circuit is it is if any point in the circuit breaks you effectively have a 2.5mm cable 'protected' by the 32A MCB :eek:
And there will be no indication of a break, i.e. all sockets work normally, if you had a break in a radial circuit the sockets beyond the fault won't work.

Ah yeah fair enough.instructor in phase 2 said that radials were more popular now but never really went into why

thanks

2011

WikiHow wrote: »

Any time i used ring circuits i protected them via a 20 amp mcb.

Why?
This means that you have effectively lost the advantages if having a ring circuit.


This is also against the regulations (ET101:2008).
Have a look at Annex 55A section 5.
This is for "Ring Final Circuits in Domestic & Similar Installations".
Under this heading in section 5.1 it states that socket circuits wired in a ring must be protected by a "Fuse/MCB rating: 35A/32A".

Bruthal

zega wrote: »

Ah yeah fair enough.instructor in phase 2 said that radials were more popular now but never really went into why

thanks

Not a fan of them myself either in domestic setups.

Other problems include the ends of the ring being connected to different MCBs by mistake. A serious blunder but it does happen, although this is more a fault of the person rather than the ring itself.

Or the earth being broken somewhere, so 32 amp circuit with 1.5 or maybe even 1 square earth, although with the RCD, it should still be ok, but not great. A similar problem can happen to radial circuits too anyway.

Bruthal

2011 wrote: »

Why?
This means that you have effectively lost the advantages if having a ring circuit.

Some advantages might still exist such as better loop impedance on longer circuits.

frankmul

2011 wrote: »

Why?
This means that you have effectively lost the advantages if having a ring circuit.


This is also against the regulations (ET101:2008).
Have a look at Annex 55A section 5.
This is for "Ring Final Circuits in Domestic & Similar Installations".
Under this heading in section 5.1 it states that socket circuits wired in a ring must be protected by a "Fuse/MCB rating: 35A/32A".

That 32amp would just be a recommendation. The max size allowed. Anything small would be safer but prone to nuisance tripping.

tomdempsey200

is it a rule or a recommendation?

i was told to change them from 20 to 32 on a reci inspection a few years back

EpiphoneSpecial

Thanks for all info. Didn't get a chance to do any work in house over weekend. Will post pics during week when I'm painting room.

2011

frankmul wrote: »

That 32amp would just be a recommendation. The max size allowed. Anything small would be safer but prone to nuisance tripping.

Where does it say that this is a recommendation?
I took a direct quotation from the ET101:2008

I was told that this was a regulation.
When I checked the regulations it confirmed what I was told.
That is the whole point of a ring circuit, a larger protective device can be installed.
Otherwise why bother?

Bruthal

2011 wrote: »

Where does it say that this is a recommendation?
I took a direct quotation from the ET101:2008

I was told that this was a regulation.


Otherwise why bother?

Bit strange that downgrading an MCB would be against regs. Where`s the danger?

2011

Bruthal wrote: »

Bit strange that downgrading an MCB would be against regs. Where`s the danger?

Nuisance tripping is more likely with say a 20A MCB. Remember a ring socket circuit typically has far more sockets on it than a radial.

My guess:
Nuisance tripping of RCDs and MCBs frequently leads to guntering such as bypassing the device altogether. Kind of like the old wrap the fuse in tinfoil trick.

brightspark

2011 wrote: »

Where does it say that this is a recommendation?
I took a direct quotation from the ET101:2008

I was told that this was a regulation.
When I checked the regulations it confirmed what I was told.
That is the whole point of a ring circuit, a larger protective device can be installed.
Otherwise why bother?

I agree why bother with a ring if you are only going to use a 20A MCB.

However, Annex 55A is listed as "Informative" meaning it's not mandatory but contains useful information that is necessary for an understanding of the Rules.

Tuco88

I recently replaced a pump in a house, and I noticed that all the MCBs were of the C type, I tested the impedance all fine (Sockets only) and noted it to my employer. Id sleep better if they were B types for the tripping current 3-5. My question is are these fine or allowed?

Id find ring circuits very practical in kitchens, They can supply a great area, reduce overload tripping, better impedance value. Reduce the amount of MCBs in the board. If the cable does break/cut the what are the odds of it not tripping? I agree worst case if it cant be repairs 2 circuits possible greater than 10 sockets on each... Granted I don't wire too many houses so maybe there not practical give the risks.

Regards OP if the joint is in the attic/crawl space might be handy to just place a double socket there if practical, Acts as a joint and my come in handy.

tomdempsey200

Tuco88 wrote: »

I recently replaced a pump in a house, and I noticed that all the MCBs were of the C type, I tested the impedance all fine (Sockets only) and noted it to my employer. Id sleep better if they were B types for the tripping current 3-5. My question is are these fine or allowed?

Id find ring circuits very practical in kitchens, They can supply a great area, reduce overload tripping, better impedance value. Reduce the amount of MCBs in the board. If the cable does break/cut the what are the odds of it not tripping? I agree worst case if it cant be repairs 2 circuits possible greater than 10 sockets on each... Granted I don't wire too many houses so maybe there not practical give the risks.

Regards OP if the joint is in the attic/crawl space might be handy to just place a double socket there if practical, Acts as a joint and my come in handy.

in the section on overcurrent protective devices it seems to state that type B 'must be used' unless there's need for C or D

if i'm reading it correctly

brightspark

Tuco88 wrote: »

I recently replaced a pump in a house, and I noticed that all the MCBs were of the C type, I tested the impedance all fine (Sockets only) and noted it to my employer. Id sleep better if they were B types for the tripping current 3-5. My question is are these fine or allowed?

Regulation 533.3.4

MCBs and RBBOs shall be selected so as to be suitable for the duty intended.
For final circuits MCBs and RCBOs shall have Type B characteristics.

For circuits where high inrush currents of the order 5-10 In May occur shall have type C.

In other words only if you expect high inrush currents should you use other than type B.

Tuco88 wrote: »

Id find ring circuits very practical in kitchens, They can supply a great area, reduce overload tripping, better impedance value. Reduce the amount of MCBs in the board. If the cable does break/cut the what are the odds of it not tripping? I agree worst case if it cant be repairs 2 circuits possible greater than 10 sockets on each... Granted I don't wire too many houses so maybe there not practical give the risks.

Annex 55A 5.1 says that ring circuits should not be used in kitchens, but you could argue that the Annex is only informative and therefore not mandatory but recommended?

Worst case is two circuits more than 10 outlets each, supplied with 2.5sq which isn't protected by a 32A MCB!

2011

brightspark wrote: »

In other words only if you expect high inrush currents should you use other than type B.

+1

but you could argue that the Annex is only informative and therefore not mandatory but recommended?

Under Annex 55A it the wording used is "normative", not "informative".
Either way at the very least it should be read as a recommendation.
In my view recommendations should only be ignored if there is a very good reason for doing so.

Worst case is two circuits more than 10 outlets each, supplied with 2.5sq which isn't protected by a 32A MCB!

Or someone takes the p!ss and installs a ridiculous number of sockets on a single circuit as I hav eseen done.

2011

Tuco88 wrote: »

Id find ring circuits very practical in kitchens

As already stated this is not permitted.

They can supply a great area

So can radial circuits.
I have seen very large rooms, homes, offices and large plants served with radial socket circuits without any issue.

reduce overload tripping

In my opinion if 20A socket circuits are tripping that is down to bad design or installation issues.

better impedance value

If you desire a lower impedance valve my advice is to use a larger cable.
Sockets such as MK logic plus can be used to terminate 4sq. mm cables without any issue.

Reduce the amount of MCBs in the board

Yes it may be possible to have less MCBs by installing ring socket circuits.
However I would rather have more MCBs.
That way the loss of a circuit will have a reduced impact on the overall installation.

If the cable does break/cut the what are the odds of it not tripping?

Quite low.
Generally the errors are made during installation and are not picked up due to little or no testing taking place.
I have seen two ring circuits "crossed" so that they are fed from two MCBs :eek:

Regards OP if the joint is in the attic/crawl space might be handy to just place a double socket there if practical, Acts as a joint and my come in handy.

Agreed

Tuco88

Annex 55A 5.1 says that ring circuits should not be used in kitchens, but you could argue that the Annex is only informative and therefore not mandatory but recommended?

Worst case is two circuits more than 10 outlets each, supplied with 2.5sq which isn't protected by a 32A MCB![/QUOTE]

Thanks for the info, This forum is very handy top lads here. I was worried about that myself, I just wanted to know how did it pass RECI inspection? the house is 7 years old at best. I didn't believe you there for a sec on the ring not being allowed in the kitchen, I never noticed that change from the Third edition noted now, last ring I put in was back in Fas . Sorry I was looking from the previous comment on the 20 Amp, Radial all the way I guess Just to note in the case stated, 32 amp over the 2.5mm² I agree its poor, But a 2.5mm² will take much greater current than 32Amps before it starts to break down, I know not relevant but from a tested point.

The one thing I very much dislike about the Regs is the grey areas in it, for example 63amp MCB covering the Tails to the consumer unit is not needed if the tails are less than 3m unless it has changed? Same with the Bathroom light on an RCD depending which zone it is. Things can be made very easy like all bathroom lights on an RCD/all tails on a 63A MCB etc...

2011

Tuco88 wrote: »

I was worried about that myself, I just wanted to know how did it pass RECI inspection?

These inspections are very hit and miss in my opinion.
A search here will confirm that.
Perhaps the threat of a inspection from CER will change the attitude of some of the RECI inspectors.

But a 2.5mm² will take much greater current than 32Amps before it starts to break down

Yes, you are correct, but only under test conditions.
We try to ensure through good design that a 2.5 would never be carrying 32A.
If you were to look at the fusing curve for a 32A B Type MCB you would see that it would operate at 36A without tripping indefenitley.
I would be quite confident that 36A going through a 2.5mm sq. cable for hours on end would cause serious damage to the cable.

brightspark

2011 wrote: »

+1


Under Annex 55A it the wording used is "normative", not "informative".
Either way at the very least it should be read as a recommendation.
In my view recommendations should only be ignored if there is a very good reason for doing so.

Not in my print (2013?) it's definitely "informative", which print version are you using?

But as you said, you would want to have a good reason for ignoring it.

EDIT... It's in the errata

http://www.etci.ie/docs/et101a12011.pdf

(The 2013 print is supposed to have the Ammendment Incorporated!)

Annex 55A, Title: Delete “Normative”, insert “Informative”.

2011

brightspark wrote: »

Not in my print (2013?) it's definitely "informative", which print version are you using?

Guess! :rolleyes:

But as you said, you would want to have a good reason for ignoring it.

That is it in a nutshell

.G.

Ok I'm confused.

If Annex 55A is informative does that mean everything in it is advice only and not a definite "rule" that must be obeyed?

For example the requirement to have isolating switches on inaccessible sockets is stated in Annex 55a but not anywhere else as far as I can see.

brightspark

superg wrote: »

Ok I'm confused.


For example the requirement to have isolating switches on inaccessible sockets is stated in Annex 55a but not anywhere else as far as I can see.

554.3.5

.G.

Freezer units on their own RCD then,appears not to be mandatory.*awaits correction*:D

brightspark

superg wrote: »

Freezer units on their own RCD then,appears not to be mandatory.*awaits correction*:D

531.2.5.4

not mandatory, can also be wired as a fixed appliance with no RCD.

You need to consider how to maintain continuity of service for any essential items.

tomdempsey200

no rcd is best imo for deep freeze


non-standard socket/no rcd should be ok too i think..customer can move appliance for cleaning etc.

i don't think they can do you for cutting off the moulded plug if ti went to court?

EpiphoneSpecial

EpiphoneSpecial wrote: »

Thanks for all info. Didn't get a chance to do any work in house over weekend. Will post pics during week when I'm painting room.

Power Coming Into Room


Cable Joiner



Socket1 (2 LIVE, 2 NEUTRAL, 2 EARTH cables)


Socket2 (need to put dry wall box in)

brightspark

So many errors!

1st pic: That unscreened earth wire is dangerously close to the exposed red live wire!
Not sure what that box is. Is it a twin socket that you are now joining the new cable into?

2nd pic: no sleeve on earth wire, neutral wire over stripped, no copper should be exposed! Not sure what you plan on doing with it?

3rd pic: Socket is too low, should be a minimum of 400mm from floor.

4th pic: again obviously too low, also no sleeve on earth wire. At a guess I'd say it's missing from the socket in pic 3.

EpiphoneSpecial

brightspark wrote: »

So many errors!

1st pic: That unscreened earth wire is dangerously close to the exposed red live wire!
Not sure what that box is. Is it a twin socket that you are now joining the new cable into?

2nd pic: no sleeve on earth wire, neutral wire over stripped, no copper should be exposed! Not sure what you plan on doing with it?

3rd pic: Socket is too low, should be a minimum of 400mm from floor.

4th pic: again obviously too low, also no sleeve on earth wire. At a guess I'd say it's missing from the socket in pic 3.

1st pic is how the previous owners did it. they put wall boxes onto skirting boards all over the house. the double socket is being removed and cables will be tidied before joining to 2nd pic.

2nd not finished job yet

3rd socket too low.. personal preference??

4th not finished yet, i cabled it so i could measure cable needed to run around room.

OP was about general concept of how to do the job.

2011

EpiphoneSpecial, if the pictures posted are representative of the standard of work in this premises the entire electrical installation urgently requires a thorough inspection followed by a written report.
This is something that should only be tackled by an experienced qualified electrician.

By adding sockets to the existing wiring you could make an already dangerous situation worse.

Ignore my advice at you own peril!

EpiphoneSpecial

2011 wrote: »

EpiphoneSpecial, if the pictures posted are representative of the rest standard of work in this premises the entire electrical installation urgently requires a thorough inspection followed by a written report.
This is something that should only be tackled by an experienced qualified electrician.

By adding sockets to the existing wiring you could make an already dangerous situation worse.

Ignore my advice at you own peril!

Cheers 2011.. I've been told that already by builder who did some work for us. But it comes down to money, new house and all, just don't have the money to get it rewired. It was built in 1970s, only upgrades done was a modern fuse board by previous owners.

In this particular room, there was 3 doubles (2 removed already, 1st pic to be removed) and I'm putting 2 new ones in. Compared to my cabling job, the cabling I took out looked liked a child did it.

2011

EpiphoneSpecial wrote: »

But it comes down to money, new house and all, just don't have the money to get it rewired.

I know that this sounds mellow dramatic but:
Have you considered what it would cost if the house were to go on fire?
Have you though about the consequences of someone being electrocuted?

Besides it this home may not need a rewire.
An inspection and report would not cost that much.

It was built in 1970s, only upgrades done was a modern fuse board by previous owners.

There is one cost saving straight away

Compared to my cabling job, the cabling I took out looked liked a child did it.

Did it occur to you that there may be far more serious wiring issues that you can’t see?

EpiphoneSpecial

yeah i get what ya mean. the oil boiler in 20/30 years old, the pipes are gun barrel, the walls aren't insulated. the list on things that could destroy the house are endless and expensive.

i'll look into getting my builders electrician out to take a look and recommend any work.

my thinking is, if i'm doing a better cabling job on sockets than what was there and the previous owners didn't burn the house down, then i'm making it better but not perfect. (not fooling myself, saying i'm as good as an electrician)

2011

EpiphoneSpecial wrote: »

the list on things that could destroy the house are endless and expensive.

Dad is that you?:D:D

i'll look into getting my builders electrician out to take a look and recommend any work.

If you get a written report then you can shop around.

EpiphoneSpecial

i'm turning into the man that me and my brothers took the piss out of for years