Possibly. Ex'n' is usually used as the cheapest way of complying with Zone 2 requirements. Intrinsically safe installations being their own set of requirements and skills. What does your client say?
We are replacing some old equipment, client simply requested Exn suitable for zone 2 IIB T3.
We have plenty of stock of intrinsically safe instruments, it was suggested this is good for zones 0,1,2 so would be OK but I thought there may be more to it than that.
IS installations require a dedicated earth, segregation, barriers, and so on. Does your client have any other IS gear on site? It has benefits, but it isn't a free lunch.
They have no IS equipment in the installation area, no barriers etc. they do not want an IS system but just maintain the existing Exn system, I suppose the question is can you introduce an IS instrument into a Exn system.
ScottyUK thanks for your replies, it turns out the item in question is triple certified IS, Exd, Exn for the North American FM/CSA models but the ATEX models we have are individually certified.
So even though they are physically the same devices new Exn models have been ordered to ensure the correct certifcation.
