I am installing temperature monitoring and alarm devices in a Class 1 Division 2 area I'd like to get confirmation of my understanding from other professionals regarding the installation. The alarm controller is in an explosion proof housing. The RTD's that we will use are considered a simple apparatus, and will be wired directly to the controller with a seal at the controller. My question is if there is any other provisions I should be making regarding the RTD installation and wiring?
The question came up when it was said asked what guarantees the controller will not supply more than the minimum power listed for a simple apparatus. As I understand it, this is not relevant because there is no device would create an arc under normal circumstances, just like terminals in a terminal box for example. Protect the wiring accordingly, but there is no electrical barrier or other provisions needed once the wiring leaves the controller past the seal.
Any discussion on this is appreciated. Thanks.