Can anybody please guide me about use of PLCs in oilfields/wellhead locations where the ambient temp goes up to 58 deg C & it's a Zone 1 IIB T3 area? TUV AK5 certification is a must for the PLC & it needs to be double redundant mainly for process protection & emergency shutdown function.

 

Look into AB's Gaurd PLC 1200. The controller have integrated I/O, DIN rail mountable and TUV equivalent SIL3 approval. SIL 3 is equivalent to TUV AK5 or AK6. The operatng temperature is rated upto 60degC.

 

See on QUADLOG SAFETY PLC Moore Product, TUV approval to level AK6, Approved to IEC61508 SIL3, CE Mark, FM Approval for class I, Div2 hazardous location, CSA approval for class I, div2 hazardous locations, ABS type approval, UL508