Barrier or Isolator Requirement for ATEX Certified NI C Series Products

Updated Sep 28, 2023

Issue Details

I have NI C Series products that connected to sensors located in Zone 2 hazardous location from non hazardous zone. Since NI C Series products are ATEX certified for Zone 2 hazardous locations application, do I still need to use Galvanic barrier or Zener barrier for protection purpose? 


NI C Series products are rated Ex nA. This means they are non-arcing devices. They can only be connected to other non-arcing sensors or devices. They are not rated for direct connection to any non-incendive or intrinsically safe (such as Ex ia, Ex ib, Ex ic) devices. If you wish to connect NI C Series products to intrinsically safe or non-incendive devices, they would need a properly rated and certified barrier or isolator in between.

Additional Information

You must also consider boundary seals if NI C Series product will be installed in the non-hazardous area and connecting to devices in the hazardous area.