Description
Metso D201477
Technical Specifications Electromechanical relay output contacts; relay contact rated for AC and DC auxiliary load switching; opto-isolation between rack logic and relay drive coil; rack 28 V DC backplane power supply; operating temperature -20 ℃ to +70 ℃; uncoated FR4 PCB; rack plug-in form factor; per-channel LED status indication.
Functional Features Relay contact isolation supports mixed-voltage field circuits; per-channel LED indicates relay energised state; hardware overcurrent protection for relay drive circuits; configurable fail-safe relay state during communication loss; relay fault diagnostic feedback to DCS controller.
Application Scenarios Central control room auxiliary alarm horn drive, low-voltage interlock relay control, water treatment pump auxiliary contactor command, power plant auxiliary system alarm output.
Material Composition Flame-retardant plastic module housing; uncoated FR4 PCB; industrial electromechanical relay components with silver alloy contacts; optocoupler isolation chips; gold-plated rack backplane edge connector; removable screw terminal blocks for field load wiring.
Structural Characteristics Horizontal rack plug-in module; front panel carries per-channel relay status LEDs and detachable field wiring terminal block; rear gold finger mates with Metso MAX rack backplane; internal isolation separates rack low-voltage logic circuits and relay contact load circuits.
Working Principle Rack CPU sends digital command values over the rack backplane bus. Module logic circuits drive optocoupler isolation chips to energise relay coils. Relay contacts open or close to switch field auxiliary loads. If communication with CPU fails, relays revert to user-configured fail-safe state.
Installation Requirements Install module in de-energised Metso MAX rack; wire field auxiliary loads to relay contact terminals; follow load voltage and current rating limits; separate relay load wiring from low-voltage instrument signal cables.
Operation Notes Do not exceed relay contact rated current and voltage; disable output channels before maintenance on field load circuits; inspect relay contacts for wear during scheduled overhaul.
