Why does ASTM E1725 consider a failure to occur when the average test temperatures exceed 139°C? It seems to me that the majority of low temperature cables have a maximum operating temperature of 90°C or 105°C?
I am looking for a standard which outlines how the ratings for intrinsically safe circuits and non-incendive circuits are effected when the field wiring for both types of circuits are routed together in the same cable tray without any separation or metal-sheathed cables.
