With this option, a Form 3 instrument can switch power for control action in all types of open-loop or ON-OFF closed-loop operations. It may be used, for example, to actuate alarms or sorting devices, or to start up or shut down external processes. Both relay types are controlled directly by the unit's LIMIT VIOLATION outputs.
The Electromechanical Relay ("R" Option) is ideal for DC or low-level switching. Two normally open and two normally closed contacts are rated at 8 amps, 250 V-AC at full resistive load. Switch lifetime at 1 amp resistive load exceeds 100,000 operations.
The Solid-State Relay ("S" Option) is suitable for controlling medium-power AC loads, or for highly repetitive operations (since its lifetime at full resistive load exceeds 10,000,000 operations). Its contacts (similar to those of the Electromechanical Relay) are rated at 3 amps, 250 V-AC at full load. Zero-crossing circuitry ensures low EMI.
NOTE: The "R" Option may NOT be used in combination with the "C," "G," "P," or "S" Option.