@Intoelectrics
If my reply has come across somewhat 'judgemental' etc then this was not the intent, the forum is normally based around the BS7671 but where we have members including myself that are experienced in other areas where separate and/or additional regulations exist then we have to make sure that members are aware of the implications of undertaking such work as it may not only effect the work one undertakes but also the insurance they carry.
I do not always post in the manner that I did here as it is a case by case call, in this case it was simply the nature of the question.
This is in no way a judgement against you or your competence, it may be the case this is just a little out of your usual request and you're used to working on other machinery so just asking for available options out there, all I was ensuring was that before advice is offered that you are aware that this is a sector of the industry that is heavily regulated, has additional insurance requirements and requires additional paperwork as there is nothing in your profile to suggest you do this kind of work.
I did say that if you were on ball with all I said then no issue but just have to make sure if you appreciate that sometimes we need to make sure.
The actual job sounds a simply alteration but one needs to ensure that implicating this small alteration is done in accordance to the relevant regulations and in this case I would suggest the BS60204-1 would cover this although I cannot comment as I am waiting for the new 2018 edition to land on my doorstep as it only came out about a month ago but I am aware there are a lot of additional regulations and changes to existing so as it stands I could only advise under the 2006 edition + A1 (2009).
PS just seen your last post #24... Yes we do get people getting beat up over a simple request and we do try to curb it where possible but sometimes we need to establish the OP's position before advise is handed out to ensure we are not giving out unsafe advise, this field of electrical work just like fire detection system design and install is one such area we need to make sure we are happy the OP is aware of what they are taking on... I have seen this first hand when people don't realise there insurance simply doesn't allow them to undertake this work regardless of their competence to do so as it is moving away from standard insurance that your average sparks would have, my insurance is probably 4X that of your average cover because I work on machinery and 3ph systems.