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#136026 - 03/05/03 07:45 AM Are these ring circuits?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
Do any of the British based electricians know if this is likely to be an Irish version of the UK ring circuit system or radial with fused plugs? Would just like to make an educated guess withouth dismantling the distribution panel.

Relatively modern installation (1970s/80s)

largeish 4 bedroom house

52 socket outlets (BS 1363 switched doubles)

10 X 20 amp MCBs and 2 X RCDs on Siemens board makred sockets.

7 X 5 amp MCBs marked Lighting
1 X 10amp marked low voltage lighting, phone sys, alarm.

1 X 20 amp marked Immersion
1 X 10 amp marked central heating & controls.
1 X 32 amp marked cooker.

There's also an Over-voltage Arrester (presumably lightening protection) and a 63amp Neozed fuse on the board.

Similar to UK specs?

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#136027 - 03/05/03 08:32 AM Re: Are these ring circuits?
Texas_Ranger Offline
Member

Registered: 12/17/01
Posts: 2343
Loc: Vienna, Austria
Anybody from the UK may correct me if I'm wrong, but I think that ring circuits are typically fused at 32A. This sounds more like 20A radial circuits wired with 2.5 mm2. It could also be a 1.5 mm2 ring, but I never heard of such a setup.

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#136028 - 03/05/03 11:06 AM Re: Are these ring circuits?
j a harrison Offline
Member

Registered: 05/22/02
Posts: 112
Loc: southampton, england
djk,

sounds like a radial circuit design with either 2.5mm or 4.00mm twin and earth (nm) cable.

the best way is to isolate each circuit and remove the socket outlets (receptacle) and find out which one only has one cable going to it.

the rest of the installation looks quite standard (in accordance with the IEE regs),

the surge arrester is a bit of an odd one as we only fit them on commercial,

A question,

is the dis board a split load, IE one main isolator for the whole board and one RCD controlled side or,
just one isolation switch (switch disconnector) and on board RCDs ??

the make of the dis board is a good one, having fitted a couple myself over the years.

John H

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#136029 - 03/05/03 01:13 PM Re: Are these ring circuits?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Yes, it sounds as though the house was wired with radial circuits throughout. The IEE Regs. only recognize a ring circuit which is fed by a 30 or 32A fuse/MCB.

The Regs. have always allowed BS1363 outlets to be wired on 20 or 30A radial circuits. The actual permissible number of outlets and floor area per circuit have changed regularly, however.

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#136030 - 03/05/03 04:35 PM Re: Are these ring circuits?
David UK Offline
Member

Registered: 10/03/02
Posts: 134
Loc: Inverness, Scotland
Certainly sounds like 20A radial circuits, considering the fact that 52 sockets are connected across 10 circuits.
Is it a lot of hassle to remove the cover & take a look at the outgoing cables from the breakers?

It would not be common UK practice to install 20A radials for all the socket circuits, however it would be quite acceptable and within IEE Regs (BS7671) to do so.

A 63A Neozed fuse would not be found in UK installations & the lightning arrestor would be very unlikely in domestic premises.

I would be interested to see how this board is laid out inside, because I understand Ireland has different (stricter) RCD protection requirements to the UK.

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#136031 - 03/05/03 05:44 PM Re: Are these ring circuits?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
the two RCDs are on the board but on different rows. I think the lightening protection may have been installed as the house is on an exposed hill and supplied overhead. Although at least the installer cared! I'd rather spend the extra few euro on the moduel than have my computers, tv, vcr etc wiped out by a lightening induced surge. Its not required by the regs though.

As far as I know RCDs have been a manditory requirement of the ETCI rules here since about 1980 on all socket circuits but they're generally found on all modern installations predating 1980 and have been normal good practice for as long as they've been available. The older ELCB switches are found on some older systems although generally get swapped for a modern RCD during any electrical work as they are not as fast-acting/reliable.

The second RCB in this system seems to be dealing with the water heater & cooker exclusively.


All modern irish boards would have one neozed or diazed fuse protecting the whole system. I've never seen any other type of fuse in use here.

Old boards would be completely Diazed usually 5, 10 and 16 amp (sockets) radials with a 32amp for the cooker or 32 amp rings. They tend to have be retrofitted with an RCD.

The power company's installation terminates on a heavy 80/100amp fuse and in more recent systems a sealed isolation switch demarkating the end of their part of the system after the meter allowing very safe isolation standardised by the ESB (powercompany).

I get the impression that things are done in a slightly more European way here than in the UK though. Lots of siemens gear, very standardised 220V 50Hz supply (since the 1930s) and schuko recessed recepticles were the original standard despite the odd BS 546 system sneaking in here and there although where it was used generally only the 15 amp sockets were installed on 16 amp radials. I've never seen a 10 amp receptical and the two amps were/are used very occasionally for lighting only. They're used for wall-switch controlled lamps even today but are not officially recognised as an irish standard. I've seen MK "keyed" BS1363 plugs used for lighting although i'd guess the 2amp round pin plugs are easier to come by.

BS1363 is the officially accepted standard now though as IS 401 & IS 401/A

Radial circuits seem to be much more commonly used here than in the UK however, not quite sure why. Lots of homes seem to have very large distribution boards in comparison to British systems at least. Usually see at least 3 rows of MCBs on hager/siemens boards.
The ETCI specifies 32 amp rings as suitable for socket outlets accepting fused plugs (IS 401) just like in the UK. Perhaps Irish sparkies frown/ed on their use? or suspect that they may need to switch to schuko someday and want to make life easy I'll we'd have to do is swap the 20 amp breakers for 16 amp and replace the wallplates.

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#136032 - 03/06/03 04:43 PM Re: Are these ring circuits?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
It does indeed sound as though Ireland is much more "Europeanized" than the U.K. in its installations.

You mentioned that the system probably dates from the 1970s era, so I thought I'd post some relevant IEE rules for radial circuits for that period that might let you work out if the electrician followed IEE Guidelines(see how useful it is to keep old code books? ).

Here are some extracts from the 14th edition (1970):

 Quote:
A.30 In domestic installations either radial or ring final sub-circuits conforming with Table A.3M may be installed to serve socket-outlets complying with B.S.1363 and stationary appliances of rating not exceeding 13 amperes.......

A.31 Each socket-outlet of a twin or multiple socket-outlet unit shall be counted as one socket-outlet for the purposes of Regulation A.30 and Table A.3M.


[img]http://members.aol.com/paulcoxwell/a3m.bmp[/img]


[This message has been edited by pauluk (edited 03-06-2003).]

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#136033 - 03/07/03 09:51 AM Re: Are these ring circuits?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
Occasionally in Ireland very heavy appliences like dryers, dishwashers and the odd washing machine that draws a steady 3KW during heating cycles or that might peak more than that will have to be wired with a 16 amp plug or BS 546 on a 16 amp spur as 13 amp plugs won't quite cover 3KW at 220V especially if the voltage is dipping lower occasionally. Generally because of lack of polarisation with schuko and availability of schuko sockets on a standard box being difficult. BS 546 gets used although i've seen schuko and i've seen heavy industrial plugs used out of sight behind the machine and a heavy switch above the counter which is prob. the safest sollution considering they're near plumbing

E.g. we had a 3KW fan heater plugged-in in Cork city centre area and it burnt out 4 plug fuses in a day!

Some older british 240 V rated central heating systems can have occasional spark problems too. 230 V gear all seems fine.

The supply is generally very close to 220V and tends to dip lower rather than being higher. Considering that the ESB has been using standardised 220V since the 1930s it's unlikely that they'll really adjust things up to 230 V even in new installations.


I wonder if newly installed distribution systems really 230 V or are they still 220 (IRL/EU) and 240 in UK as they always have been?

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#136034 - 03/07/03 10:16 AM Re: Are these ring circuits?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
a lot of older 220V stuff was rated 3000 W as it shipped with a 16 amp schuko plug.. things have changed a bit since the standardisation on 230 V though. 2850 W seems to be the upper design limit.

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#136035 - 03/07/03 10:38 AM Re: Are these ring circuits?
C-H Offline

Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
 Quote:

I wonder if newly installed distribution systems really 230 V or are they still 220 (IRL/EU) and 240 in UK as they always have been?


The Brits are said not to care. In fact, I think the UK standards still says 240V +/-6%. In law it has changed to 230V +10/-6%, though. There was concern among lighting manufacturers when this was passed that the 230V stuff wouldn't handle actual voltage encountered in the UK. (I.e. it would be above the official 253V)

I don't think it was the purpose of the EU to spread the 'who gives a damn anyhow'-attitude to all of Europe, but it has suceeded.

 Quote:

a lot of older 220V stuff was rated 3000 W as it shipped with a 16 amp schuko plug.. things have changed a bit since the standardisation on 230 V though. 2850 W seems to be the upper design limit.


Or 2200W @ 230V. Can you guess why these wattages have been chosen?

If the load is resistive (reasonable for a kettle, space heater, drier or washing machine) this means that current will be exactly 10A or 13A when used on 240V.

A bit ironic, isn't it?

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