# Search results

1. ### Power socket on motorcyle

Is the existing wiring able to handle another 15A circuit?
2. ### Power socket on motorcyle

Its easier to light cigarettes at high speed :lol:
3. ### Max Z's for 32A Type C MCB

Its very easy to calculate Zs yourself. You dont need a reference book. Type C breaker requires X10 rated current to meet 0.4 & 5 second disconnect time, voltage is 230. You have current and voltage so just use Ohms law to calculate impedance: 230V / 320A = 0.718 Ohms rounded to 0.72...
4. ### Upgrading CU

I apologies for creating confusion, and as you have pointed out 543.1.1 refers to earthing and not bonding. The OP did not make it clear if we were talking about earthing or bonding. I decided to comment on both & point out that earth conductors less than 16mm are not always non compliant to...
5. ### Upgrading CU

543.1.1 basically says you can do 1 of 2 things. 1- Either select the earth from table 54.7 which means 16mm earth for line conductors up to 16mm. 2- Use the equation from 543.1.3 to caculate the earth size based on fault current and the time it takes the protective device to operate. If...
6. ### Upgrading CU

As already said 10mm is fine for main bond (up to 25M in length) 16mm for earth conductor is preferred but smaller is not necessarily non compliant. Use the Adiabatic equation
7. ### fitting new rangemarster cooker

What does the manual say? If you dont have one tou can get it here: http://www.rangemaster.co.uk/index_Rangemaster_Manuals.htm hope that helps
8. ### Cable drilled but didn't blow any CU fuses

, The 3A fuse would only blow of the load side was shorted. If the supply to the fuse is shorted a fuse will go further upstream
9. ### on/off switch for an electric oven

:shock: Surely if you provide a switch it must be accessible?
10. ### Basic visual checks

While you look around pay attention to location and positions of electrical equipment. The cooker isolator switch should be near the cooker but without leaning over it to switch off. Check light positions in the bathroom ie if its directly over the bath, or that the light is suitable for the...
11. ### Changing light from plug to mains

Unusual for a light circuit to be 16A :? How is the existing light operated? Is it by a seperate switch? When you say wire into a 3A box I assume you mean one of these with a surface mount box...
12. ### house rewire under floorboards

I agree. Earthed metal conduit will also be a better solution instead of using safeplates As long as you don't assume you know what is correct, and seek advise at every stage then im sure you are on the right track. Whoever is going to sign the electrical installation certificate will need...
13. ### TT System - RCD protection

17th requires RCD protection on all circuits now, unless your house is wired in earthed metal conduit.
14. ### house rewire under floorboards

Hi, I agree with Pensdown. You will find "The Electricians guide to the building regulations" to be a very informative book, and I would recommend reading it before you get stuck in. Regards
15. ### rcd operation calcs

Its Ohms law :D V=IR therefore R=V/I V= 50 as metalwork cannot rise above this figure I= 30mA RCD trip current therefore R=50/0.03 which comes to 1666.66666666
16. ### Spur to garage, what to expect from quotes ?

It would have to be a fused spur The existing circuit will need to comply with current regs so I think you will need an RCD at the consumer unit It might need to be 3.5M, but im sure someone else can confirm this Steel wire armour. Whatever cable is used must be suitable for outdoors &...
17. ### radial fuse question

I would personally be suspicious as to why a 16A has been fitted, and would check the circuit thoroughly before changing anything. If you confirm that its 2.5 throughout and radial length does not exceed 27 metres, then you could probably upgrade to a B20 MCB. If there is no RCD fitted then a...
18. ### The usual shed installation question

If its a TN-C-S system you shouldnt export the earth to the shed if there are extraneous parts (metalwork that offers earth potential). Instead you should put an earth rod in, and make the shed TT
19. ### 2391

Take a look at the chief examiners reports. They will give you an insight into why people fail and the pass rate. http://www.city-and-guilds.com/cps/rde/xchg/SID-0AC0478C-B054AD3C/cgonline/hs.xsl/17381.html As far as books are concerned you will need GN3 as the exam is based on this...
20. ### how to isolate fuse box power

Why did your friend ask you to do it?? Your obviously as clueless as they are :?