Isolation switch wiring convention

Hi
Quick question: whenever I've seen DP isolation switches in consumer units the supply wires invariably enter the switch from the top, obviously because the busbar is connected to the bottom. However, I'm just about to add an isolation switch between the meter and a connection block and was wondering whether I should maintain this convention, i.e. that the meter tails are connected to the uppermost contacts of the switch?
I only ask because the meter tails are quite short and it will determine the position of the isolation switch enclosure.
Many thanks
Ross
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Don't do it upside down. The electricity might fall out.
Christian.
P.S. Just make sure you don't swap the "load" and "supply" terminals, if they are marked as such.
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Whoops I think I spilled some but I quickly mopped it up!
;-)

Well it does have the typical isolation switch symbol printed on the front
| | 0 0 \ \ | |
so does the direction have any significance, i.e. does it indicate which is the load?
Many thanks
Ross
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I guess the switch might specify which are the Feed and Load terminals, in which case I used them even if they were at the top. Nor reason though why you couldn't feed the tails in from below and then run up inside to the other terminals. Assuming there is enough space.

--
Chris French, Leeds

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writes

You could buy some new tails. Only a few quid.
Adam
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wrote:

connect them.
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I think this group has been down this road many times. At the end of the road the tails do belong to the owner of the house not the leccy co. Adam
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It is far better to take any steps that are necessary to do a job properly. If this means removing the seals on the meter, then remove the seals and do the work correctly and safely. If you're already taking the seal off the mains fuse holder, then why not take the seal off the meter as well and replace the tails with properly measured and tidy ones and make the job look the way it should.
The electricity supplier will be more grateful to you, if you ask them to check the work and allow them to make sure that the installation is safe and secure, bot just for them, but for your own safety also. A test request is sent easily by postcard, obtainable from any electrical wholesaler, and they send you enough notice of appointment to be there and have them carry out, what is only about an hours work, and then when the seals are replaced, it at least shows that the work is up to some sort of safe standard, or it won't get connected and sealed until it is put right.
All new builds and refurbs' must go through this procedure, so it is not an uncommon occurance for any of the electricity suppliers.
Do the job correctly first time, and save yourself problems in the future.
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Yup, more than a few posts about that in the past!
Leccy companies don't appear to give two hoots about the seals on the company fuse being broken to do work, but are seals on the meter a different matter? ISTR that according to some posts it seems that some meters have a modular approach that enables you to change the load tails without breaking the seal.
Incidentally, a quick look at my meter tails reveals that although the tails between the fuse and meter are coloured black and red the meter tails are both grey - only being identified with a 1" bit of coloured electricians tape wrapped around them. Is this acceptable? I'm planning to change the CU soon, and will use the opportunity to chnage the tails for properly coloured ones if the current grey ones are not compliant.
cheers Richard
-- Richard Sampson
email me at richard at olifant d-ot co do-t uk
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It is quite normal. 25mm cable usually comes with grey sheaving. Under the sheaf, a layer of insulation can be found, which is colour coded (still black and red, if you're quick!)
Christian.
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The tails are sheathed and you are looking at the sheath. If you look inside the CU, you will likely see the sheath is stripped off to reveal red and black insulation.
--
Andrew Gabriel

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The red and grey wires are not your property. They may be smaller than 25mm and it is not uncommon to see 10mm cables between the meter and 100A fuse
I'm planning to change the

The grey wires are about as compliant as you can get.
Adam
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the *main fuse* being broken - safety gains of doing so when replacing a CU far outweigh chance of objection from supplier. (Anyone tapping in to their supply through the fuse carrier is a prime candidate for a Darwin award, right? No, I won't repeat the allegedly-true story of a colleague in his roadie days performing an impromptu in-situ copper-weld to connect up the lighting rig to the main supply panel at a continental gig location wot had no convenient place to make a Proper connection and the minutes to first soundcheck ticking away...) Supply companies are a lot *less* relaxed about the meter seals themselves, as breaking that seal allows a "safer" bypass of the meter (an illicit use for a Henley block!) and possible fiddling with the meter adjustment. Thus-and-therefore, many of us d-i-y'ers are reluctant to fool with the meter tails, even though they indeed belong to us...
Stefek
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But we mean the seals on the terminal cover, not the seals on the actual meter. The terminal cover is meant to be removed if you're working on the consumer side of the supply, so it is normal to remove the seals of the terminal cover if you're replacing the tails to a new consumer unit, say. If you were to remove the manufacturers seals on the working part of the meter, then you're in line for some sort of "being illegal" action.
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