http://www.electriciansforums.co.uk/ en Tue, 07 Sep 2010 17:42:20 GMT vBulletin 60 http://www.electriciansforums.co.uk/images/misc/rss.png http://www.electriciansforums.co.uk/ http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21890-help-row-lights.html Tue, 07 Sep 2010 00:25:31 GMT Hello everyone im NVQ level2 but has never done strobe lights that will turn on/off in rows.

I am working in an old ice house & its my next job but I have no real idea if each row will come from the same CB in the CU then split to make rows or each row on its own CB in the CU (circuit braker/CB) (consumer unit/CU).

also as NVQ level 2 can I rewire on my own without an electrician (just rewire only) or does one need to be on site as the labour boss of the ice house seems to think its ok to rewire & change how the 4floor house is to be wired? just a question as im ok with so much work but some feels like im not allowed yet untill I have part-p

Thanks...

Graham Blackburn (unemployed Grimsby) ]]> Electrical Wiring, Theories and Electrical Regulations gram http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21890-help-row-lights.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21884-changing-2-way-lighting-intermediate.html Mon, 06 Sep 2010 20:59:18 GMT To change a 2 way lighting circuit to an intermediate circuit, do I just replace the two way switch with an intermediate switch, then use a 3 core... To change a 2 way lighting circuit to an intermediate circuit, do I just replace the two way switch with an intermediate switch, then use a 3 core twin an earth from the intermediate switch to the additionally two way switch? ]]> Electrical Wiring, Theories and Electrical Regulations whazza22 http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21884-changing-2-way-lighting-intermediate.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21874-pat-test-50mtr-2-5-mm-ext-reels.html Mon, 06 Sep 2010 19:53:04 GMT Pat testing of110v 50meter 2.5mm extension reels they are brand new can I pass them or do I have to cut them in half so they are 25 meters long ???... Pat testing of110v 50meter 2.5mm extension reels they are brand new can I pass them or do I have to cut them in half so they are 25 meters long ??? Help ]]> Electrical Wiring, Theories and Electrical Regulations stumas http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21874-pat-test-50mtr-2-5-mm-ext-reels.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21866-electrical-distribution-help.html Mon, 06 Sep 2010 17:42:43 GMT Well i'm a building services engineer but im not very experienced and have come across a problem.
As a ring main is generally only allowed to supply 100 sq m. I have a building that is about 70m long and the bottom 2 rooms are roundly about 50 sq m each. The DB board is at the top end of the building, the current wiring is a 2.5mm ring main from the DB board.

The Current wiring provides me with a voltage drop of roughly 30v. Which is very excessive for a final circuit not to mention the extrememly high earth fault impedance.

To solve this problem i have estiamted in a 40A MCb and the DB then a 16 sq mm cable running up to the end of the building and maybe a mini DB board or even just a fused 32A switch then the 2 rings coming off that.

I need to try and keep as much of the exisiting 2.5mm cable in as i can.

Thank you in advance for your help. ]]> Electrical Wiring, Theories and Electrical Regulations Ben Revell http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21866-electrical-distribution-help.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21864-bathroom-not-rcd-protected.html Mon, 06 Sep 2010 17:35:41 GMT Hi, I have been asked to replace a bathroom light, the current circuit is not RCD protected and is connected to rewireable fuses. Do I need to... Hi,
I have been asked to replace a bathroom light, the current circuit is not RCD protected and is connected to rewireable fuses. Do I need to install a new CU with RCDs or can I replace the light and connect it to the existing CU and issue a minor works cert. ]]> Electrical Wiring, Theories and Electrical Regulations geezza http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21864-bathroom-not-rcd-protected.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21859-kmf-switch-isolator-problems-please-help.html Mon, 06 Sep 2010 16:04:34 GMT Hi I am unsure on the regs with this I have a 100a main fuse but need to run tails outside in armoured cable into loft of extension I know that... Hi I am unsure on the regs with this I have a 100a main fuse but need to run tails outside
in armoured cable into loft of extension I know that I need a kmf switch but I'm struggling to find a small 100 amp one (not enough room for the big wylex ones) can I use a Switch Fuse Moulded Single Pole & Neutral, with 80A HRC Fuse or does it need to be equal to the main service fuse ?

Thank you. ]]> Electrical Wiring, Theories and Electrical Regulations jaybhill http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21859-kmf-switch-isolator-problems-please-help.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21855-tail-lengths.html Mon, 06 Sep 2010 12:16:52 GMT Hi All I'm moving a DB about 5m from the head, what is the requiremnt for tails this long, an isolator, Switch fuse or does it depend on the supplier and their requirements? ]]> Electrical Wiring, Theories and Electrical Regulations EddieB http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21855-tail-lengths.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21850-criticism-installation.html Mon, 06 Sep 2010 09:49:32 GMT hello fellow sparks i was hoping that there would be another electrician using these forums who could help me in handling a situation that i will... hello fellow sparks
i was hoping that there would be another electrician using these forums who could help me in handling a situation that i will describe below.
I am a self employed sparky with my two sons working as apprentices, over the last twelve months i have worked very hard to obtain new clients, i try to keep away from domestic work, and i have no intention of taking part p, i am far more at home working in industrial premises and on machinery.
While not deliberately attempting to snatch work away from another contractor, i have sent hundreds of letters out to prospective customers, one of whom, a joinery manufacturer, asked for a quotation to disconnect 30 machines from their old premises and relocate at a new premises.
Upon disconnecting at the old premises i found that there were multiple machines fed from one circuit breaker, in one case there were five three phase machines fed from one circuit breaker, in some cases earth rings were not fitted and in all cases there was no earth link from the earth ring to earth terminal in the distribution board, the client was aware that they could not use certain machines whilst others were working.
The client has been using an electrician for years, there are two directors of the joinery who are quite happy with him but a manager who is not.
We completed the machine move in time and machine downtime was minimal, i have been back on a couple of occaisions for breakdown cover which proved to be starter or isolator breakdown on the machines themselves, i did not charge for this, we completed the move in may this year.
last week the manager phoned me up asking to see me, i immediately attended whereupon i was given a copy of a letter from the other contractor with three pages of "faults" that he claims we are guilty of, it also claims that if health and safety were to visit the premises they would shut them down, closer inspection of the "faults" mostly revolve around socket outlets not being rcd protected, i am aware that in industrial premises where rcd can cause nuisance tripping they can be omitted so we did, the other contractor also claims we have mixed neutrals with earths, work untidy, left holes in distribution bards, and have not put identification on old red/yellow/blue phases in an old distribution board, as far as i can tell that is our only crime, the contractor is using words that can only be described as scare mongering.
This contractor in four years has never issued a completion certificate or minor works certificate, i am sure he has not attended a 17th regs course, as described earlier he has fed multiple machines from one supply, has never fitted earth links, and has not used new colour identification himself.
I do not wish to get as petty as himself, but our standard of work has basically shown up his work, he is now attempting to scare the client by using the regulations and blind them with science.
what can be done in situations like this, i am confident enough that our work is of a higher standard than the criticiser, however the client is worried.
any suggestions please
many thanks ]]> Electrical Wiring, Theories and Electrical Regulations dragonspark http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21850-criticism-installation.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21846-switchroom-signage-legislation.html Mon, 06 Sep 2010 08:51:19 GMT Hello All, Looking for some advice here. I am in the proccess of writing a report at my work highlighting the need for all of our electric shock... Hello All,

Looking for some advice here. I am in the proccess of writing a report at my work highlighting the need for all of our electric shock first aid signage to be replaced in our switchrooms etc. In most cases it is up to 25 years out of date.

Looking for some legislation or regulations that state the requirment to have this signage.

All i can find at the moment is within the electricity at work regs,
though the section the signage is mentioned in only appears to be relevant to mines.

Any advice would be much appreciated.

John ]]> Electrical Wiring, Theories and Electrical Regulations john86uk http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21846-switchroom-signage-legislation.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21844-farm-supplies.html Mon, 06 Sep 2010 08:16:16 GMT having read on other posts about people having split phase farm supplies, id like to be educated as to what they are, and why they exist. :D having read on other posts about people having split phase farm supplies, id like to be educated as to what they are, and why they exist.

:D ]]> Electrical Wiring, Theories and Electrical Regulations johnboy6083 http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21844-farm-supplies.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21817-sunbed-house.html Sun, 05 Sep 2010 19:06:45 GMT A customer has asked me to put in a supply for a sunbed in his house. He says it needs a 50amp single phase supply. So i was thinking putting in a... A customer has asked me to put in a supply for a sunbed in his house. He says it needs a 50amp single phase supply. So i was thinking putting in a 50amp c curve mcb from the fuse board which has a spare way fed in 10mm t+ e 10meters then into a rotary switch to the sunbed. The bed has not got an industrial plug. iv never wired a sunbed before, any thoughts? anyone dismantled one to get through the doorway?
thanks peeps ]]> Electrical Wiring, Theories and Electrical Regulations mattyevz http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21817-sunbed-house.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21792-zs-readings.html Sun, 05 Sep 2010 10:37:47 GMT Three reasons why the direct measurment Zs reading of a circuit is smaller than the callculated Zs = Ze + (R1+ R2) Three reasons why the direct measurment Zs reading of a circuit is smaller than the callculated Zs = Ze + (R1+ R2) ]]> Electrical Wiring, Theories and Electrical Regulations john h owen http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21792-zs-readings.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21791-ir-test-luminaires-explosive-atmosphere.html Sun, 05 Sep 2010 10:19:02 GMT As part of a Peridic Inspection test, on a 230v circuit having luninaires in a Explosive Atmophere area - the reason why the switch controlling the... As part of a Peridic Inspection test, on a 230v circuit having luninaires in a Explosive Atmophere area - the reason why the switch controlling the luninaires has been left in the off position? ]]> Electrical Wiring, Theories and Electrical Regulations john h owen http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21791-ir-test-luminaires-explosive-atmosphere.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21775-recording-studio-wiring.html Sat, 04 Sep 2010 19:40:54 GMT Hi Guys

I've been asked by a neighbour to wire his new recording studio. He is operating out of his garage at the moment and is complaining about small electric shocks and major 'noise'. As he is looking to go semi-pro he is converting an old barn and has asked for me to do my best to kep the noise down. I am a fully qualified sparky ( before anyone asks).

Anyway the studio will consist of 4 rooms, a lounge area, a mixing room, a sound room for the band and another small room for the drummer.

What I am thinking of proposing after a good bit of research on the net is the folowing:

A new 16mm supply from the origin (16mm required only for low impedance levels)
A new dedicated earth placed outside the building with as low impedance as I can reasonably get.
A consumer unit for supplies to the oil boiler, lighting and general power.
A consumer unit fed from a 20 or 32A UPS (load unknown), which then feeds power outlets to the soundroom, recording equipment and computers.
All circuits will be wired in SY cable with the screen earthed at the consumer unit including lighting. All cabling will run as straight as possible with minimal crossings. Any crossings would be at right angles.
A ring main wired in Data trunking will be put in the sound room. The cable will be 4mm.
The same with the mixing room only all sockets will be kept as close together as possible. The cabling for the ring main would be run side by side instead of in a loop around the room to prevent equipment being placed inside the 'loop'.

Another method is to forget about the UPS and run 20A radials to a socket in each the mixing room and the sound room. From that a Power conditioner would be plugged in allowing a perfectly clean supply along with ground loop separation to each component. The only problem with this is that all sockets would be in the one area instead of being around the room.

Does anyone here have any experience of wiring a recording studio?

Any advise or help would really be appreciated.

thanks

Jonny ]]> Electrical Wiring, Theories and Electrical Regulations JonAW http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21775-recording-studio-wiring.html http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21757-can-two-dwellings-upstairs-downstairs-flat-share-pme-main-earth.html Sat, 04 Sep 2010 07:57:00 GMT Just been to a subdivided house - now up+downstairs flats. There are two earth rods which go to a single earth block under the floor, then leave the... Just been to a subdivided house - now up+downstairs flats. There are two earth rods which go to a single earth block under the floor, then leave the block as two earths up to the C/Us. (Effectively each flat is connected to the two spikes). There is a single mains head with 100A BS1361 fuse which then loops up to another single 100A main fuse (for one flat) and then loops on to another such fuse for the other flat (DNO fitted).

Question: can this supply be converted to PME?
Issues: can a single earthing conductor feed two separate dwellings? I've got distant voices saying in my head that this isn't allowed.

Thanks for any advice. ]]> Electrical Wiring, Theories and Electrical Regulations acvc http://www.electriciansforums.co.uk/electrical-wiring-theories-electrical-regulations/21757-can-two-dwellings-upstairs-downstairs-flat-share-pme-main-earth.html