I have a Client that will not provide a Risk Assessment to omit an RCD Commando Socket for a Data Cabinet. He wishes to employ a local isolator for the Cabinet, however he is concerned that the PDU Strip that arrived on site from the factory and pre-fitted within the data cabinet would still need an RCD. It is my opinion that the Factory built Data Rack is classed as a piece of equipment and as such does not form part of the Contractor's installation. If the Rack had arrived on site without the PDU strip fitted and it was installed by the Contractor then this would form part of the installation and therefore would require an RCD. Any advice/assistance would be appreciated.
I think that Andy has also made an error worrying about direct contact with damaged cables etc by anyone. Whilst that could happen given enough various circumstances, realistically it is very very unlikely. I would point out that a single RCD for a rack of servers (which might take 100A of mains, probably 3x32A supply) would be foolish, the idea of fitting one each is worse! We have an electrical system which depends on proper earthing of exposed conductive parts, and automatic disconnection of supply by CPDs, yet this regulation is determined to fit even more unnecessary RCDs! The scope for RCD protection is way too wide, it should only be for sockets where portable appliances are likely to be used by unskilled persons, and the servers in a rack should be out of scope for portable appliances separately, as you need tools to make them portable.
There is a serious problem with the standards making process, and that is that interactions between various ones from differing sources lead to foolish and unnecessary outcomes. The most obvious one is electric cars (chargers) not being class 2 because someone didn't see that they could not safely be earthed in the external environment, which we all know and have a lot of regulations to reduce risks to presumably acceptable levels. However street furniture using PME is considered entirely satisfactory and does not cause a significant number of accidents. We need to be consistent on the basis of real risk only, not on "what if" scenarios.
I think that Andy has also made an error worrying about direct contact with damaged cables etc by anyone. Whilst that could happen given enough various circumstances, realistically it is very very unlikely. I would point out that a single RCD for a rack of servers (which might take 100A of mains, probably 3x32A supply) would be foolish, the idea of fitting one each is worse! We have an electrical system which depends on proper earthing of exposed conductive parts, and automatic disconnection of supply by CPDs, yet this regulation is determined to fit even more unnecessary RCDs! The scope for RCD protection is way too wide, it should only be for sockets where portable appliances are likely to be used by unskilled persons, and the servers in a rack should be out of scope for portable appliances separately, as you need tools to make them portable.
There is a serious problem with the standards making process, and that is that interactions between various ones from differing sources lead to foolish and unnecessary outcomes. The most obvious one is electric cars (chargers) not being class 2 because someone didn't see that they could not safely be earthed in the external environment, which we all know and have a lot of regulations to reduce risks to presumably acceptable levels. However street furniture using PME is considered entirely satisfactory and does not cause a significant number of accidents. We need to be consistent on the basis of real risk only, not on "what if" scenarios.
