Product Core Brief
- Model: MVTU11K1CD0751G
- Brand: ALSTOM / GEC ALSTHOM / GE Vernova
- Series: ALSTOM MV Undervoltage Protection Relay Family
- Core Function: Definite-time AC undervoltage relay used to detect voltage dips, loss of voltage, and undervoltage conditions, then initiate trip, interlock, or control actions.
- Product Type: Undervoltage Relay / Voltage Protection Relay / MV Protection Relay
- Key Specs: AC voltage measurement | Definite-time undervoltage trip | Adjustable time delay | Relay output contacts | Optional programmable logic sequences | No Ethernet/IEC 61850 as standard
- Condition: New Original / New Surplus
Product Introduction
ALSTOM MVTU11K1CD0751G is a definite-time AC undervoltage relay from the ALSTOM MV protection relay family. It is used in medium-voltage switchgear, protection panels, generator excitation systems, LCI drive schemes, and industrial auxiliary supply circuits where reliable undervoltage detection is required.
The relay monitors AC system voltage and compares it with a preset threshold. When the measured voltage falls below the setpoint for the configured time delay, the relay operates its output contacts to trip a breaker, block a drive, initiate a sequence, or raise an alarm. Some variants support limited programmable logic or state-sequence functions, allowing basic interlock and sequencing without a separate PLC.
Public spare listings describe MVTU11K1CD0751G as an undervoltage protection relay, sometimes also referenced as an integrated protection device or digital output module. However, third-party descriptions vary widely. Some pages label it as a full Micom Px4x feeder relay with IEC 61850, Modbus, DNP3, and multi-function protection; others list it only as a generic digital discrete output module. These descriptions are inconsistent and should not be used alone for replacement. The installed nameplate, auxiliary supply voltage, VT ratio, trip logic, and panel drawing must be confirmed before procurement.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Full Model | ALSTOM |
| Product Type | Definite-Time AC Undervoltage Relay |
| System Platform | ALSTOM MV Protection Relay Family |
| Core Function | Undervoltage detection, trip initiation, interlock, and control sequencing |
| Measured Quantity | AC system voltage via VT input |
| Protection Function | Undervoltage with definite-time delay |
| Auxiliary Supply | AC or DC depending on build code; commonly 110 VAC or 220 VAC variants — confirm from nameplate |
| Output Contacts | Relay output contacts for trip/alarm/interlock |
| Communication | Not standard; confirm from nameplate if any serial/Ethernet option is fitted |
Quality Control Process
- Visual and code check: Confirm MVTU11K1CD0751G labeling, front fascia, terminals, and mounting hardware.
- Nameplate verification: Confirm auxiliary supply voltage, VT rating, frequency, and firmware/logic option.
- Voltage threshold check: Verify undervoltage setpoint against the panel setting sheet.
- Timing check: Confirm definite-time delay operation at reduced voltage.
- Output contact check: Verify trip/alarm contacts operate and reset correctly.
- Final packing: Record test results, apply asset labels, and ship with terminal protection.
Replacement Pitfall Guide
❗ Do not assume it is a full Micom P14x/P34x feeder relay. Some listings describe MVTU11K1CD0751G as a multi-function protection relay with IEC 61850, Modbus, and Ethernet; that claim is not reliably supported by official documentation and should be verified from the nameplate.
❗ Do not treat it only as a digital output module. Some spare pages list it as a discrete output module, but its primary function is undervoltage protection.
❗ Confirm auxiliary supply and VT rating. Applying the wrong auxiliary voltage or mismatching the VT input can prevent correct operation.
❗ Check logic and contact mapping. If the installed unit uses programmable sequences or interlocks, the replacement must match the same logic configuration.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
| Original Model | Replacement / Successor Model | Compatibility Level | Migration Notes |
|---|---|---|---|
| ALSTOM | ALSTOM | Direct | Like-for-like replacement when nameplate, auxiliary supply, VT input, and logic match. |
| ALSTOM | Other MVTU11 variant | Needs Adaptation | Confirm undervoltage range, delay, contacts, and auxiliary supply. |
| ALSTOM | ALSTOM/GE Micom P14x/P34x | Needs Adaptation | Modern numerical relay; requires VT wiring, logic, contacts, and communication review. |
| ALSTOM | Modern undervoltage relay | Needs Adaptation | Requires panel drawing, VT ratio, trip logic, and contact mapping verification. |
- Typical use: MV switchgear, feeder and generator protection panels, LCI drive protection, excitation system interlocks, auxiliary AC supply monitoring, and industrial undervoltage trip schemes.
- Key verification points: MVTU11K1CD0751G part number, auxiliary supply voltage, VT rating, undervoltage setpoint, time delay, output contacts, and panel logic drawing.
