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Topic Title: Changing CU's
Topic Summary: ESC advice
Created On: 26 April 2009 11:58 AM
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 27 April 2009 07:34 PM
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OMS

Posts: 19468
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I'll have to leave you to continue the debate BOD so all yours - I'm away for my supper

Regards

OMS

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Failure is always an option
 27 April 2009 07:47 PM
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spinlondon

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Originally posted by: OMS
Quite - thats why I disagree with this:

Having One RCD to cover the whole installation would mean that if there was a fault causing the operation of the RCD on a ring, the lights etc. would go off.


If you claim that a single RCD is not compliant I will argue that a single lighting circuit is also non complaint - go figure

Regards

OMS


That's your opinion.
IMHO an ill-founded and poorly argued opinion, In fact I would say not argued at all opinion.
Would you suggest that an installation consiting of one light and six sockets on one ring main should have two lighting circuits?
 27 April 2009 08:06 PM
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perspicacious

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"IMHO an ill-founded and poorly argued opinion, In fact I would say not argued at all opinion." spin

"The Regs now call for discrimination between circuits." spin

Could you please enlighten us with the 16th Reg number which didn't require discrimation and the 17th Reg number that now does?

Any chance?

Regards

BOD
 27 April 2009 08:22 PM
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spinlondon

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Originally posted by: perspicacious
"IMHO an ill-founded and poorly argued opinion, In fact I would say not argued at all opinion." spin

"The Regs now call for discrimination between circuits." spin

Could you please enlighten us with the 16th Reg number which didn't require discrimation and the 17th Reg number that now does?

Any chance?

Regards

BOD


Short answer Bod. No.
Go hassel the guys on the PIR coding query, Division of circuits Thread, maybe they'll answer you.

Edited: 27 April 2009 at 08:23 PM by spinlondon
 27 April 2009 08:34 PM
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perspicacious

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""The Regs now call for discrimination between circuits." spin
Could you please enlighten us with the 16th Reg number which didn't require discrimation and the 17th Reg number that now does?"

"Short answer Bod. No."

Never mind, I'm sure your honesty will be appreciated by the readers now.....

Regards

BOD
 27 April 2009 08:48 PM
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spinlondon

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Originally posted by: perspicacious
""The Regs now call for discrimination between circuits." spin
Could you please enlighten us with the 16th Reg number which didn't require discrimation and the 17th Reg number that now does?"

"Short answer Bod. No."

Never mind, I'm sure your honesty will be appreciated by the readers now.....

Regards

BOD


Allways honest. One of my few faults, that and modesty of course.
 27 April 2009 09:17 PM
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mark2spark

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Originally posted by: OMS

Is it just me:

Went to see a CU change job


Why a consumer unit change then - if all the existing circuits appear fit for reconnection what is actually wrong with the existing con unit that warrants replacement and reconnection to an existing system

Regards

OMS


We can, of course, spend several hours typing out reams of prose, much like a labour government does, or we can cut to the chase.

I'll indulge:
I went to see a job that was a reported fault of intermittent cutting out of the power sockets. I found at the back of a wylex 4 way rewireable fuse board, a broken 'rivet' that held the clasp of the fuse onto the busbar. There was intermittent touching and seperating of the copper pieces due to hot/cold/creaking floorboards/whatever, and there was evidence of burning.
I don't believe that this is 'fixable' in a manufacturers replacement part way.

Therefore I recommended a change to a modern Consumer Unit, as it was the most cost effective way of effecting a repair and providing RCD protection which the installation did not have.

That was a bit quick of you to condemn me ohms... tut tut

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 27 April 2009 09:18 PM
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mark2spark

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Originally posted by: perspicacious

Don't you know anything OMS?

You can do a CU change in a morning and walk away not only with £500+ (cash) for less than £100 of materials but also leaving the client believing that it is a panacea and very happy that you didn't have to damage any decoration or lift any floorboards......

Regards

BOD


Backed up by the usual suspect

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 27 April 2009 09:24 PM
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mark2spark

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Originally posted by: spinlondon

If it's a like for like change, does the Cu require an RCD at all?


For a long time, this was exactly my argument.

Is a certificate required if changing an analogue room stat for a digital programmable one?

However, the ESC have now stated the position as they see it, and, if the test is one of reasonableness, then it would be reasonable, methinks, to follow the advice/guidance given.

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 27 April 2009 09:27 PM
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mark2spark

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Originally posted by: perspicacious

"And of course, if it's cash then I guess no paperwork either"

Well OMS, the installers whine about Part P but conveniently forget that had they complied with the Wiring Regulations for not only the installation but for the issuing of certificates with test schedules, Part P would never have been introduced......

Regards

BOD


Quite how the avoidance of the MP's daughter being electrocuted could have occured with your sweeping across the board condemnation of all your subjects my lord escapes me.

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 27 April 2009 09:30 PM
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mark2spark

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Originally posted by: sparkingchip

fit a dual RCD unit with lots of spare ways for future use,


Originally posted by: mark2spark
...a new main switch rcd CU will fit in the cupboard space just right, a doubled up rcd board won't fit at all...




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 27 April 2009 10:00 PM
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perspicacious

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"Quite how the avoidance of the MP's daughter being electrocuted could have occured with your sweeping across the board condemnation of all your subjects my lord escapes me."

Strange that no one has been willing to confirm that all their work was compliant and I&T&C......

If anything, there has been more confirmation of non-compliance on the forum if you carefully read the questions and posts....

Regards

BOD
 27 April 2009 10:06 PM
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mark2spark

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Originally posted by: perspicacious

"The Regs now call for discrimination between circuits." spin

Could you enlighten us with the 16th Reg number which didn't require discrimation and the 17th Reg number that now does?

Regards

BOD


I really don't see why you feel the need to 'contribute' to a thread when you don't provide anything productive.
Anyone with half a brain realises that Spin is commenting on the industry's interpretation of the 314.1 (i) requirement.

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 27 April 2009 10:11 PM
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mark2spark

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Originally posted by: spinlondon
Having one lighting circuit does not to my mind, or as far as I can see by my logic breach the regulations.


314.1 (iii) now asks one to take account of any danger that might arise from the failure of a single circuit such as a lighting circuit.

"Every installation SHALL be divided into circuits..."

So falling down the stairs in a one bedroom flat due to not being able to see cos of only one (failed) lighting circuit could be a problem (in a 17th install situation)
(IMO)

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 27 April 2009 10:13 PM
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mark2spark

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Originally posted by: deapea
How did a TT installation covered by a 100mA rcd ever comply?


I'm sure Bod could provide you with the getting on for 100 years old reg

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 27 April 2009 10:20 PM
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mark2spark

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Originally posted by: OMS
We are either applying 314.1 relating to division of an installation in to circuits to minimise inconvenience, avoid danger etc or we aren't.

OMS


Ah!!!

I'll go further.
It appears (IMO) that if you follow the logic through, the split 2 x rcd CU doesn't comply, and rcbo's are the only sure way.
Any faulty circuit causing an rcd that controls more than one circuit to trip causes some inconvienience.
If there's another way, (RCBO) and cost of course isn't an issue , then one hasn't completely minimised the inconvienience.

Just some of it.

Might as well just have one rcd then with the odd circuit non rcd (like an immersion or CH FCU)

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 27 April 2009 10:24 PM
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mark2spark

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Originally posted by: perspicacious

Come on OMS, let the poor guy answer my question about the Reg numbers before drawing and quartering him

Regards

BOD


It's simply NOT FAIR is it when people don't want to play your twisty the words around game, is it
time for bed sonny jim

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 27 April 2009 10:24 PM
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sparkiedave

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Interesting to see how varied the opinions can be on a subject I would have thought was fairly straight forward, I would go down the RCBO route with this, yes one lighting circuit isn't ideal but it's not unique, one lighting circuit on a full rewire I would look at as shoddy practice,
but a customer isn't going to go for a rewire of the lighting on the grounds of inconvenience, I usually encourage the fitting of a small emergency light if possible where there is only one lighting circuit, and push for low energy lamps too, gets round the "breaker trips every time a bulb goes" scenario, several NIC assesments of doing things this way have proved to be ok
 27 April 2009 10:25 PM
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perspicacious

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"314.1 (iii) now asks one to take account of any danger that might arise from the failure of a single circuit such as a lighting circuit.
"Every installation SHALL be divided into circuits..."
So falling down the stairs in a one bedroom flat due to not being able to see cos of only one (failed) lighting circuit could be a problem (in a 17th install situation)
(IMO)"
Mk2sp

"I'm sure Bod could provide you with the getting on for 100 years old reg"

You probably need to look no further than BS 7671:2008 for the definition of danger (p22).

I'm struggling to grasp how the use of electrical energy would cause your falling down the stairs scene and fulfill the definition of danger.

Regards

BOD
 27 April 2009 10:26 PM
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mark2spark

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Originally posted by: spinlondon

Originally posted by: perspicacious
Any chance?

BOD


Short answer Bod. No.

Go hassel the guys on the PIR coding query, Division of circuits Thread, maybe they'll answer you.


Wahhhh....!!!
The bigger boy shouted at me...

-------------------------
I am prone to talking complete bol***ks at times, please accept my apologies in advance.
IET » Wiring and the regulations » Changing CU's

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