Sorry to bump this , i been working on the Subs for 10 years heres the deal.
You need both a BESC and persons card to work on the subs. You have to do the persons training before you can do the besc assessment
The persons card comes in 3 different types. Person, competent person and Senior authorised person. This training is classroom based and carried out by the natinal grid. It is simply a course that goes over all there safety rules ect
Persons card is the very basic one for any trade working on a sub. You work under the supervision of a Competent person. Card is valid for 3 years about ÂŁ180
Competent person card is for those that need to hold national grid safety documents. They are in charge of all other persons working under the safety document. Theres all sorts of other authorisations you can get on this card like live working ect.
To get this card you have to have previously held a persons card and provide proof of at least 9 days working on site.This card is valid for 1 year only. Cost ÂŁ275
Authorised person. Dont worry about getting this, unless you've worked for national grid you wont get it. This is the main guy that does the switching on the substaion. Always a NGC employee. This is the main man the guy that issues the safety docs ect
Besc.
This is an on site assessment. Half day course. You get asked questions you learnt on your persons course and asked to identify equipment ect. Cost ÂŁ175 valid for 3 years
Couple of links
Energy & Utility Skills Register
Energy & Utility Skills Register
Thought it might be of use as i know there's a few that are interested in this side of the trade