GEC Alsthom / GE MVTP31F1CB0751D Overcurrent Protection Relay
Overview
The MVTP31F1CB0751D is a 3-phase static relay from the GEC Alsthom Midos MVTP series, originally manufactured in Stafford, UK. Now part of GE Vernova legacy protection portfolio, the MVTP31 is designed for high-impedance busbar protection schemes and restricted earth fault (REF) systems. It continuously supervises buswires and main current transformer circuits to detect open-circuit faults on buswires or CTs, preventing unwanted operation of busbar protection. This unit adopts a draw-out Midos case for easy maintenance and replacement. It is discontinued by the original manufacturer and supplied as spare parts for existing substation installations.
Main Features
- Three-phase buswire supervision for high-impedance busbar protection
- Setting range: 1 V to 16 V via front panel DIL switches
- Selectable operate time delay: 3s or 10s
- Continuous rated AC input: 600 V rms, no external components required
- Hand-resettable mechanical flag for fault indication
- Draw-out Midos housing, hot removable without disconnecting wiring
- Suitable for 50Hz / 60Hz power systems
Model Definition
- MVTP: Midos buswire supervision relay series
- 31: 3-phase unit (MVTP11 = single phase)
- F1CB: Hardware & auxiliary supply configuration
- 0751D: Setting range, firmware and case variant
Typical Applications
- High impedance busbar differential protection in HV/MV substations
- CT open-circuit supervision for restricted earth fault protection
- Retrofit spare parts for legacy GEC Alsthom / AREVA Midos protection systems
Note: Although listed as overcurrent protection relay in many supplier listings, per GE Vernova original datasheet, MVTP31 is a buswire supervision relay rather than standard feeder overcurrent protection relay.
Compatible Product Models
Compatible Main Protection Relay Models: MCAG14, MCAG34, MFAC14, MFAC34Supporting Accessories: Midos draw-out base, current transformer (CT), stabilizing resistor
FAQ
Q1: Is the MVTP31F1CB0751D a standard overcurrent protection relay?
A1: No. Although it is titled as an overcurrent relay in many supplier listings, it is essentially a buswire and CT circuit supervision relay. It is not used for feeder overcurrent tripping, but specifically monitors CT open circuits and broken buswires to prevent mal-operation or failure of the main busbar protection system.
Q2: Which main protection relays is the MVTP31F1CB0751D compatible with?
A2: It is perfectly matched with GEC Alsthom Midos series high-impedance differential protection relays, includingMCAG14, MCAG34, MFAC14, MFAC34. It cooperates with these main relays to complete full busbar protection and circuit monitoring functions.
Q3: What is the voltage setting range and configuration method?
A3: The adjustable voltage setting range is1V to 16V AC. Users can set parameters directly via the front panel DIP switches, with no external resistors or auxiliary components required.
Q4: What time delay options does this relay support?
A4: It provides two optional fixed operation delays: 3 seconds and 10 seconds. The relay will trigger alarm output and protection locking after the set delay when abnormal circuit conditions are detected.
Q5: How to reset the fault operation indicator?
A5: This relay is equipped with a hand-resettable mechanical flag. The flag will latch automatically after protection operation and remain locked until manually reset on site by maintenance personnel.
Q6: Is this a draw-out type relay and can it be removed live?
A6: It adopts a standard Midos draw-out plug-in housing. It can be pulled out for inspection, maintenance or replacement live in the cabinet without disconnecting secondary wiring, greatly improving maintenance efficiency.
Q7: What power frequency systems is this relay applicable to?
A7: The relay is universally compatible with 50Hz and 60Hz AC power systems, suitable for legacy high and medium voltage substation projects worldwide.
