Author Archives: rsmodules

ALSTHOM 3BE101 | 24VDC Digital I/O Rack Mount Control Module ALSPA DCS Power Plant Refinery – Field Service Notes

Component Snapshot At-a-Glance Model: 3BE101 Alt. P/N: No direct factory cross-reference; ALSPA series 3BE099 / 3BE102 are expanded I/O variants with different channel counts Product Series: ALSPA GEC ALSTHOM legacy distributed DCS control system Hardware Type: Rack/DIN rail plug-in digital I/O module, conformal coated PCB, metal front mounting bracket Key Feature: 16 isolated digital inputs…

ALSTHOM MVAA14B1AA0785C | Electrical Reset Auxiliary Midos Draw-out Relay 110/125VDC Medium Burden – Field Service Notes

Component Snapshot At-a-Glance Model: MVAA14B1AA0785C Alt. P/N: MVAA14D1AA0785C (low-burden coil variant, different DC draw); MVAA11 (self-reset no latch); MVAA13 (hand-reset mechanical latch) Product Series: MVAA Midos auxiliary relay family, shared rack base footprint with MCGG/MVAJ/MVAX protection relays Hardware Type: Full withdrawable plug-in electromechanical auxiliary relay, yellow aluminum industrial chassis, transparent front inspection cover Key Feature:…

ALSTHOM MCHN02D1AB0005A | Undercurrent Low-Load Midos Draw-out Protection Relay Power Plant Pump Dry Run – Field Service Notes

Component Snapshot At-a-Glance Model: MCHN02D1AB0005A Alt. P/N: MCHN02H1AB0004A (high-burden coil variant, incompatible DC winding draw); MCGG series (overcurrent only, no low-load detection logic) Product Series: MCHN Midos static numerical protection relay family, shared rack base footprint with MCGG/MVAJ relay lineup Hardware Type: Full withdrawable plug-in static undercurrent protection relay, yellow aluminum industrial chassis, transparent front…

ALSTHOM MVAX12B1DA0753A | Trip DC Supply Supervision Relay Midos Draw-out Substation Hardware – Field Service Notes

Component Snapshot At-a-Glance Model: MVAX12B1DA0753A Alt. P/N: MVAX12D1DA0753A (low-burden coil variant, different winding draw); MVAX21/MVAX31 (full trip loop supervision, incompatible wiring logic) Product Series: MVAX Midos draw-out supervision relay family, cross-compatible with MCGG/MVAJ protection rack bases Hardware Type: Electromechanical plug-in trip supply monitoring relay, yellow aluminum withdrawable chassis Key Feature: B-series medium burden 110/125VDC coil,…

ALSTHOM MVAX31C1DF0754A | Midos Trip Circuit Supervision Relay Continuous CB Trip Loop Monitoring 110VDC Draw-out Unit – Field Service Notes

Component Snapshot At-a-Glance Model: MVAX31C1DF0754A Manufacturer: GEC ALSTHOM (later AREVA Grid, now GE Vernova Grid) Alt P/N: MVAX21 (only post-closing supervision, cannot monitor breaker open state); MVAX31S1DC0754A (different coil burden, pinout mismatch); MVAX91 (triple MVAX31 integrated unit, larger rack footprint) Product Series: MVAX Midos trip circuit supervision relay family, unified draw-out rack platform compatible with…

ALSTHOM MCGG22D1CB0753C | Single Phase IDMT Overcurrent Protection Relay Midos Draw-out MV Substation Feeder Motor Backup – Field Service Notes

Component Snapshot At-a-Glance Model: MCGG22D1CB0753C Manufacturer: GEC ALSTHOM (later AREVA, GE Vernova Grid) Alt P/N: MCGG52H1CB0753C (2-phase + earth fault + high-set, incompatible protection logic); MCGG22H (with high-set instantaneous element); MCGG42 (two-phase variant) Product Series: MCGG Midos static numerical protection relay family, draw-out substation rack form factor Hardware Type: Draw-out plug-in single-phase static overcurrent relay,…

ALSTHOM MVAJ13D1GB0780A | Midos Low-Burden DC Tripping Auxiliary Relay MV Substation Protection Interlock – Field Service Notes

Component Snapshot At-a-Glance Model: MVAJ13D1GB0780A Manufacturer: GEC ALSTHOM (later AREVA, GE Vernova Grid) Alt P/N: MVAJ13B1GB0780A (High-burden coil variant, incompatible coil impedance); MVAJ23 series (larger multi-contact frame, cannot direct swap) Product Series: MVAJ13 compact hinged armature tripping relay, Midos standard draw-out rack form factor Hardware Type: Draw-out plug-in electromechanical auxiliary trip relay, transparent front protective…

ALSTHOM MVAJ23B1AB0757B | MVAJ23 High Burden Draw-out Trip Relay MV Substation Circuit Breaker Interlock – Field Service Notes

Component Snapshot At-a-Glance Model: MVAJ23B1AB0757B Manufacturer: GEC ALSTHOM (later AREVA, now GE Vernova Grid) Alt P/N: MVAJ23R1AB0505F (low burden coil variant, coil impedance incompatible); MVAJ10 series (smaller contact count, cannot substitute multi-interlock schemes) Product Series: MVAJ 20-series hinged armature trip/auxiliary relay, Midos draw-out rack form factor Hardware Type: Draw-out plug-in mechanical tripping lockout relay, yellow…