What class designation should a pathway have when it is NOT monitored for integrity?

When a pathway is not monitored for integrity, it should be designated as Class D. Class D pathways are typically used in systems where the integrity of the wiring is not continuously supervised, meaning that if the wire is broken or shorted, the system will not detect this fault. This can be suitable for certain applications where the risk associated with unmonitored pathways is deemed acceptable or where cost constraints preclude the use of more complex monitoring solutions.

In contrast, Class A pathways are designed for systems that require integrity monitoring, providing loop redundancy to ensure communication even if a fault occurs on one segment of the pathway. Class B pathways also do not monitor integrity but are structured differently, allowing for some degree of zonal monitoring. Class E is typically associated with more specific types of applications or systems and is not applicable in this context. Thus, Class D is the correct designation for unmonitored pathways, as it directly aligns with the lack of integrity supervision.