Author Archives: rsmodules

ALSTOM MFAC34N1AA0001A | Multi-Leg High Impedance Differential Midos Draw-out Relay Low-Burden 110VDC Busbar & Transformer Protection – Field Service Notes

Component Snapshot At-a-Glance Model: MFAC34N1AA0001A Alt. P/N: MFAC34B1AA0001A (medium-burden coil variant, higher DC draw); MFAC14 (single-zone 2–4 leg compact differential); MCAG34 (circulating current balanced differential, different summation logic) Product Series: MFAC Midos static high impedance differential protection relay family, shared rack base footprint with MCGG/MVAJ/MCTI/MVTU relays Hardware Type: Full withdrawable plug-in static multi-infeed high impedance…

ALSTOM MCTI40N1AB0751G | 3-Phase Instantaneous Overcurrent Midos Draw-out Relay Low-Burden 110VDC Breaker Fail Protection – Field Service Notes

Component Snapshot At-a-Glance Model: MCTI40N1AB0751G Alt. P/N: MCTI40F1AB0751F (medium-burden coil variant, higher DC draw); MCTI39 (2-phase only, missing C-phase monitoring); MCTI19 (single-phase compact unit) Product Series: MCTI Midos static instantaneous current detection relay family, unified rack base with MCGG/MVAJ/MVAX/MVTT protection relays Hardware Type: Full withdrawable plug-in static 3-phase instantaneous overcurrent relay, blue painted aluminum industrial…

ALSTOM MVAJ21L1GB0771B | Economising Self-Reset Trip Midos Relay Low-Burden 110VDC Breaker Trip Logic – Field Service Notes

Component Snapshot At-a-Glance Model: MVAJ21L1GB0771B Alt. P/N: MVAJ21B1GB0771B (medium-burden coil variant, higher continuous DC draw); MVAJ27 (fixed drop-off delay latch); MVAJ53 (mechanical hand-reset flag, no economiser circuit) Product Series: MVAJ Midos electromechanical trip relay family, unified rack base footprint with MCGG/MVAX/MVTT protection relays Hardware Type: Full withdrawable plug-in attracted armature trip relay, blue aluminum industrial…

ALSTOM MCGG22L1CB0753E | Single-Phase IDMT Overcurrent Midos Draw-out Relay Low-Burden 110VDC 1A CT – Field Service Notes

Component Snapshot At-a-Glance Model: MCGG22L1CB0753E Alt. P/N: MCGG22B1CB0753E (medium-burden coil variant, higher DC draw); MCGG52 (2-phase + earth fault); MCGG62 (3-phase full set) Product Series: MCGG Midos static overcurrent protection relay family, shared rack base with MVAJ/MVAX/MVTT relays Hardware Type: Full withdrawable plug-in static single-phase overcurrent relay, blue aluminum industrial chassis, front DIP switch calibration…

ALSTOM MBCI01N1AB0761B | Symphony DCS Bus Communication Interface Module 24VDC Low-Burden Backplane Card – Field Service Notes

Component Snapshot At-a-Glance Model: MBCI01N1AB0761B Alt. P/N: MBCI01B1AB0761B (medium-burden backplane power variant, higher rack draw); 3BE series (standalone discrete I/O, no backplane bus bridge) Product Series: ALSTOM Symphony Harmony / Symphony Plus DCS backplane communication interface family Hardware Type: Rack plug-in blue metal chassis bus bridge module, conformal coated PCB, front diagnostic LED bank, edge…

ALSTOM MVAW11B1AB0513A | Midos Draw-out Single-Phase Over/Undervoltage Static Protection Relay 110VDC Medium Burden – Field Service Notes

Component Snapshot At-a-Glance Model: MVAW11B1AB0513A Alt. P/N: MVAW11L1AB0513A (low-burden coil variant, lower DC draw); MVUA11 (non-Midos panel mount voltage relay); MCGG series (current-only hardware, no AC voltage measurement logic) Product Series: MVAW Midos static voltage protection relay family, shared rack base footprint with MCGG/MVAJ/MVTT/MCTI relays Hardware Type: Full withdrawable plug-in static single-phase AC voltage relay,…

ALSTOM MVTU11K1CD0751G | VT Voltage Transformer Supervision Midos Draw-out Relay Low-Burden 110VDC – Field Service Notes

Component Snapshot At-a-Glance Model: MVTU11K1CD0751G Alt. P/N: MVTU11B1CD0751G (medium-burden coil variant, higher DC draw); MVAW11 (standalone over/undervoltage, no VT fault discrimination); MCGG series (current-only, no voltage circuit supervision) Product Series: MVTU Midos static VT supervision relay family, shared rack base footprint with MCGG/MVAJ/MVAX/MVTT relays Hardware Type: Full withdrawable plug-in static voltage transformer monitoring relay, blue…

ALSTOM MVAJ27L1FB0784D | Time Delayed Drop-off Mechanical Latching Midos Trip Relay Low-Burden 110VDC – Field Service Notes

Component Snapshot At-a-Glance Model: MVAJ27L1FB0784D Alt. P/N: MVAJ27B1FB0784D (medium-burden coil variant, higher DC draw); MVAJ28 (electrical reset only); MVAJ53 (no internal drop-off delay) Product Series: MVAJ Midos electromechanical trip/lockout relay family, shared rack base with MCGG/MVAX/MVTT protection relays Hardware Type: Full withdrawable plug-in latching trip relay, blue aluminum industrial chassis, transparent front window with mechanical…

ALSTOM MAVS01L1AB0501D | Midos Draw-out Frequency Speed Monitoring Relay 24VDC Low Burden Rotating Machine Protection – Field Service Notes

Component Snapshot At-a-Glance Model: MAVS01L1AB0501D Alt. P/N: MAVS01H1AB0501E (high-burden 24VDC coil variant, higher DC draw); MCHN series (only undercurrent detection, no frequency/speed measurement) Product Series: MAVS Midos static speed/frequency monitoring relay family, shared rack base mechanical footprint with MCGG/MVAJ/MVTT protection relays Hardware Type: Full withdrawable plug-in static frequency/speed detection relay, blue painted aluminum industrial chassis,…

ALSTOM MVAW11B1AB9007A | Midos Draw-out AC Over/Undervoltage Static Protection Relay 110VDC Medium Burden – Field Service Notes

Component Snapshot At-a-Glance Model: MVAW11B1AB9007A Alt. P/N: MVAW11L1AB9007A (low-burden coil variant, lower DC draw); MVUA11 (compact panel mount non-Midos voltage relay); MCGG series (current-only, no AC voltage measurement) Product Series: MVAW Midos static voltage protection relay family, shared rack base footprint with MCGG/MVAJ/MVTT/MCTI relays Hardware Type: Full withdrawable plug-in static single-phase AC voltage relay, yellow…