by ericmark »
Sun Nov 09, 2008 5:56 pm
Competent person. A person who possesses sufficient technical knowledge, relevant practical skills and experience for the nature of the electrical work undertaken and is able at all times to prevent danger and, where appropriate, injury to him/herself and others. This is the highest level and is above skilled so as a competent person you can make out your own installation certificate!
So as I am sure you realise we only know what you tell us. So first I would follow links in the projects section and down load the Part P document. This gives you a sample of the forms required. Although the forms available on the IET web site have not got “On Line Version” printed all over them, so I would use forms from IET site if you do DIY.
The form is split into three sections or it can be and allows three signatures for design, Installation, and testing. So you can get an electrician to test for you but he will need to sign combined form not issue his own.
The meters can be hired and so you could do it yourself but remember must be traceable record so sneaking a meter out of work for the day is no good.
The planning man is ultimately responsible for site safety and if he does not like the readings he is authorised to either test himself or get someone in to test at the councils expense.
So in theory you could get all the readings by calculations and not use a meter at all. Just a martindale tester to check polarity. Under normal circumstances I would say this is a bad idea as you can miss errors but at end of day it’s not your call it’s down to man from council to ensure all is correct.
So if you use a new role of cable to do ring main then measure what is left you can easy work out length. And the tables tell us how many mV/A/m each type of cable is.
The only thing one can’t calculate is Ze with a TT supply and tripping time and current for the RCD. Also the insulation really needs measuring.
So do you already know what Ze, Zs, R1 + R2, R1 + Rn, etc means.
I assume you are not a “Competent person” as BS7671:2008 defines but I don’t know how much you really know. Are you aware that there are new rules about cables buried in walls? Have you considered Ali-tube cable? Etc. I am uncertain about what happens if the installation does not comply. Maybe you just have to correct, but maybe the council can charge again if it fails? I have never had anything fail so I don’t know.
Eric