Protection Coverage

The MIV II 3000 combines phase overvoltage and undervoltage, ground overvoltage, voltage-unbalance and overfrequency or underfrequency protection in one drawout relay. The voltage functions use independent definite-time elements, while the two frequency elements can be configured for overfrequency or underfrequency supervision.

Monitoring, Records and Diagnostics

The relay records up to 24 events with time tags to the nearest millisecond. MIV II 3000 oscillography stores one 24-cycle record at eight samples per power-frequency cycle, with triggering from protection pickup or operation, configured digital input, self-test events or a communications command.

• Frequency and phase-voltage metering from the front display or communications link.
• Last-five-trip information available from the local display.
• Continuous self-test diagnostics during operation and at power-up.
• Flash memory supports field firmware updates using the approved MII tools.

Control and Communication

A 2 × 16-character LCD, five-key front keypad and six status LEDs support local interrogation. Four LEDs, two inputs and four of the six outputs can be user configured. Remote access uses Modbus RTU through an isolated front RS232 port or the rear RS485 port at 300 to 19,200 bps.

Technical Data Summary

Applications

Suitable functions include voltage and frequency protection in automatic transfer systems, generators, motors, power lines and busbars. Selection must consider the installed VT arrangement, voltage range, control-power source, I/O assignment and the existing protection philosophy.

Installation and Wiring Review

1. Confirm the complete order code and compare the nameplate before removing the installed relay.
2. Isolate control power and voltage inputs using the site lockout and test procedure.
3. Verify VT connection, safety ground, trip circuit, programmable inputs and output contacts against the approved drawing.
4. Use fork or ring terminals on the terminal block and install a suitable disconnect device near the relay.
5. Load or verify settings, communication address, baud rate, logic and I/O mapping before functional testing.
6. Complete secondary-injection and breaker-control tests before returning the protected equipment to service.

Ordering FAQ

Is this an active-production relay?
The MIV II is listed by GE Vernova as a legacy product with manufacturing discontinued. Availability is therefore confirmed against current stock.

What information should accompany an inquiry?
Provide the full order code, quantity, front and side nameplate photos, firmware revision, supply voltage, VT arrangement and required delivery location.

Can a different MIV II suffix be substituted?
Only after verifying protection model, voltage range, language, control-power range, coating option, case compatibility and the existing wiring assignment.