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Conduit and trunking

Posted: Sat May 30, 2009 8:59 am
by AjayK46
I am going to place all the mini trunking required to add some additional sockets to existing ring mains prior to getting an electrician in to do the cabling and appropriate certification.

Where a cable runs horizontally through an internal wall (Lounge to bedroom) does it have to be in a coduit at the point where it passes through the wall?

Thank you.

Posted: Sat May 30, 2009 4:38 pm
by kbrownie
HI AjayK46,
Really I'd expect your electrician to help you with this, I assume you are taking a feed from another socket then taking the cable through the wall.
If that is the case you need to ideal protect the circuit with an RCD or at least the additional sockets.
But the answer is, no need to run conduit through wall, it could help at a later date if you needed to replace the cable but as the rest of the additional circuit is in mini trunking a bit pointless.
KB

Posted: Sat May 30, 2009 8:04 pm
by AjayK46
Thanks kbrownie

Yes all the ring mains are protected by rcd on the consumer unit. The electrician will simply be extending the size of each of 2 rings slightly within applicable constraints.

Out of interest I have storage radiator heating which run off a separate fuseboard which is not rcd protected. These are circuits that were installed at least 10 years ago. Would it be a good idea to have that fuseboard changed to have rcd protection and if so would the existing white twin and earth need to be changed to grey by the electrician?

Cheers

Posted: Sun May 31, 2009 2:59 pm
by kbrownie
AjayK46,
The fuse box/consumer unit does not need to be changed uness becomes dangerous or unsuitable for use. Unless you want to upgrade?
If your current set up allows RCBOs to be installed on the side that is not being protected by RCD that could be an option. No need to change cable either as long it is safe and not a potential hazard.
ie condition of cable is good and insulation resitance above 1 mega ohm. Grey or white cables not an issue.
KB

Posted: Mon Jun 01, 2009 7:45 am
by AjayK46
If I did decide to take the opportunity of getting the consumer unit used for the storage radiators upgraded while the electrician is on site, would it be of any benefit to have my immersion heater dedicated circuit (used daily as no gas) moved to the same consumer unit? I am on an Economy 7 tariff.

Thank you for your help.

Posted: Mon Jun 01, 2009 12:08 pm
by kbrownie
AjayK46,
I would recommend storage heaters always are on seperate circuits. The guidelines are that storage heaters with vessels holding above 15 litres, should be on own circuit. even though your may not be, one day it may be upgraded to a higher capacity.
KB

Posted: Thu Jun 04, 2009 7:19 pm
by AjayK46
Hi kbrownie,

Apologies but a little confused about your reply. My storage radiators are already on their own consumer unit with a dedicated cable and fuse for each radiator. This consumer unit only has power going to it during the off peak night time economy 7 tariff. What I was wondering is if it would be sensible to move my dedicated immersion heater circuit onto the same consumer unit as the storage radiators. I know this would mean that it would only be possible to heat the immersion during the off peak power, but as the accumulated 7 hour period can vary as to when it occurs during the night it would at least guarantee that when my immersion was heating it was at the cheap rate.

Posted: Fri Jun 05, 2009 7:52 am
by kbrownie
Sorry AjaxK46,
missed your point!
I have no doubt that your electrician will be able to offer you sensible advise.
I don't see why not, of course it will then become a new circuit and will need RCD protection, your alternatives as mentioned before are RCD protected CU/Fuse Box or every circuit(s) being protected by a RCBO.
Hope this helps
KB

Posted: Fri Jun 05, 2009 11:16 pm
by bd3cc
Previously E7 systems had 2 feeds to the immersion, 1 from the E7 cu, which would only operate during off peak hours and heat the whole cylinder, and one from the main cu which was available at any time, and was used as a daytime top up, and would only heat half a tank. this was done either through having 2 elements in the cylinder, or a dual element.
It is worth noting that any electricity used during off peak hours, id at the cheaper rate, so worth putting timers on washing machines/etc to operate overnight.