ok, I read this with some interest. I'm not an electrician, but I do have a fairly good understanding of things. 

The title of the thread almost sounds like something I would put in place, but not as a fixed rule. I don't use the words 'banned' or 'forbidden' I tend to say 'the company standard is'.

Having consistency is a big benefit, and making rules that reduce the amount of ongoing maintenance or inspection is always good, as is reducing the amount of confusion.  

Making it a company standard, rather than banning things also means you can have non-standard things where economics or circumstances get in the way, such as an area served with a BS3036 board, an SRCD is an appropriate solution, sometimes. 

I made our standard preclude the use of SRCDs, as they are expensive, unreliable, easily damaged and don't protect the cable supplying the socket if someone was to damage it. The cost of replacing two SRCDs is higher than fitting a single RCBO to a modern board. 

One of our sites has bought plug in RCDs and has put them on every appliance, I shudder to think about the cost of that, or the practicalities of it, plus the PAT test that will be added and then, of course, the RCD part wont be getting tested.

I was a bit concerned about the type A and AC RCDs, but having just checked my stores, all the Schneider RCBOs are type A, but I have a Dorman Smith RCBO, and that is type AC, slightly bizarrely, the Dorman Smith RCBOs fitted to the board some 15 years ago are type A. 

I think I just need to check that they are type A when I purchase them in the future. 

I just thought it might provide a bit of insight as to where these rules come from

ok, I read this with some interest. I'm not an electrician, but I do have a fairly good understanding of things. 

The title of the thread almost sounds like something I would put in place, but not as a fixed rule. I don't use the words 'banned' or 'forbidden' I tend to say 'the company standard is'.

Having consistency is a big benefit, and making rules that reduce the amount of ongoing maintenance or inspection is always good, as is reducing the amount of confusion.  

Making it a company standard, rather than banning things also means you can have non-standard things where economics or circumstances get in the way, such as an area served with a BS3036 board, an SRCD is an appropriate solution, sometimes. 

I made our standard preclude the use of SRCDs, as they are expensive, unreliable, easily damaged and don't protect the cable supplying the socket if someone was to damage it. The cost of replacing two SRCDs is higher than fitting a single RCBO to a modern board. 

One of our sites has bought plug in RCDs and has put them on every appliance, I shudder to think about the cost of that, or the practicalities of it, plus the PAT test that will be added and then, of course, the RCD part wont be getting tested.

I was a bit concerned about the type A and AC RCDs, but having just checked my stores, all the Schneider RCBOs are type A, but I have a Dorman Smith RCBO, and that is type AC, slightly bizarrely, the Dorman Smith RCBOs fitted to the board some 15 years ago are type A. 

I think I just need to check that they are type A when I purchase them in the future. 

I just thought it might provide a bit of insight as to where these rules come from