Quote Originally Posted by fifty60 View Post
What is meant by the "external electrical system"? Is it the electrical system in the non-hazardous area? What if the process connected equipment (a float switch for example) only has electrical wiring going to a Type Z purged enclosure located inside the Hazardous area?

Would using MI cable between the float switch and where the wire terminates at the purged enclosure suffice to satisfy the process seal requirement?
Yes using MI would fill the requirements of sealing, but may not be legal for other uses.