What are the different types of Automation Redundancy?
Automation redundancy can be accomplished via three methods - cold, warm and hot.
Cold Redundancy Cold redundancy is for those processes where response time is of minimal concern and may require operator intervention. As an example, take two belt presses, each with its own dedicated control panel. If one belt press becomes inoperable, the operator can resume operation by simply starting the other press.
Warm Redundancy Warm redundancy is used where time is somewhat critical but a momentary outage is still acceptable. In this scenario, a momentary bump can be expected. During this bump, the valves, motors and other devices might shutdown temporarily, and the sensors may not report back to the PLC system during the bump.
Hot Redundancy Hot Redundancy is used when the process must not go down for even a brief moment under any circumstance. An example of a hot redundancy system application is a membrane or BAF application. In both instances, the process may not require the hot redundancy capabilities, but during a backwash, redundancy could be critical.