George, You have a good point.
If the power of the source is limited, then there should be no way a device can cause a problem. But, if that is the case, why do we have ex rated and non-ex rated versions of the same devices that will be downstream from the coupler? I know that intruments and passive components like AFDs and junction boxes all have ex and non-ex versions. I will not recommend a non-rated component for an IS system. I am not a safety engineer.
Anyway, we have exhausted my nickel’s worth of knowledge on Intrinsically Safe slip rings.
I’m looking forward to see if anyone else has any thoughts on this.