ABB REM615 Motor Protection and Control Relay

Overview

The ABB REM615 is a dedicated motor protection and control relay for the protection, control, measurement and supervision of asynchronous motors in manufacturing and process industry. ABB positions it as the main protection for the motor and its associated drive, typically on circuit breaker or contactor controlled HV motors and on contactor controlled medium-sized and large LV motors. As a member of the Relion family and the 615 series, it shares a common engineering environment, case design and communication stack with the other 615 relays used on the same switchboard.

Seven Star LLC supplies the ABB REM615 to oil and gas producers, refineries, water utilities, cement and mining operations in the Sultanate of Oman and the wider GCC. From Muscat we help maintenance and projects teams select the standard configuration, sensor or CT inputs, I/O and protocol options, and we prepare quotations that include spare plug-in units and accessories for critical pump and compressor drives.

How the ABB REM615 Protects a Motor

The ABB REM615 covers the full operating life of a motor, from start-up through normal running to fault clearance. Thermal overload protection models the heating of the machine so that it can be loaded fully without premature insulation ageing. Motor start-up supervision checks start current and start time, locked rotor protection trips a stalled machine, and protection against too frequent starts stops repeated hot starting from damaging the winding. A restart inhibit function, with a settable inhibit time, and an input for blocking simultaneous restarts help avoid voltage collapse when several large motors try to re-accelerate after a dip.

Around these motor-specific functions the relay adds non-directional earth-fault protection, negative phase-sequence current unbalance protection, backup overcurrent, motor running stall (jam) protection, loss-of-load supervision and phase reversal protection. Configurations B, C and D additionally provide directional earth-fault, three-phase undervoltage, negative-sequence overvoltage, positive-sequence undervoltage and frequency protection. Where a process must keep running, an emergency start feature lets operators override thermal protection to start a hot motor deliberately.

Engineering Design of the ABB REM615

Four standard configurations are available. Configurations A, B and C use conventional current and voltage transformers, while configuration D combines one conventional residual current input with three combi-sensor inputs for phase currents and voltages, connected with RJ-45 connectors. ABB notes that current sensors do not saturate at high currents and that voltage sensors remove the risk of ferroresonance, which makes the ABB REM615 suitable for compact medium-voltage switchgear such as UniGear Digital, SafeRing and SafePlus.

The optional RTD/mA module for configurations A and B measures up to eight analogue signals through six RTD inputs and two mA inputs, so stator winding and bearing temperatures can feed the thermal model directly. Earth-fault protection can use a cable (core balance) current transformer for sensitive detection or phase CTs in Holmgreen summation connection, and the relay’s interlocking or an external stabilising resistor helps prevent unwanted earth-fault operation during start-up CT saturation. Optional hardware adds three arc detection channels and high-speed outputs that cut total operate time by typically 4 to 6 ms compared with normal power outputs.

Key Features of the ABB REM615

The list below draws on the functions table and application notes in the ABB REM615 product guide.

• Thermal overload protection for motors (MPTTR) that tracks heating during starts, running and cooling.
• Motor start-up supervision (STTPMSU) with settable start current, start time, locked rotor time and restart inhibit time.
• Motor load jam protection and loss-of-load supervision for pumps, conveyors, crushers and fans.
• Two stages of negative-sequence overcurrent protection for machines to detect supply unbalance and single phasing.
• Emergency start-up function to allow a deliberate hot start of critical drives.
• Circuit breaker, disconnector and earthing switch control with position indication and master trip lockout.
• Up to 18 multipurpose protection instances that can trip or alarm on RTD/mA values or analogue GOOSE data.
• IEC 61850 Edition 2 with GOOSE, process bus support, Modbus, DNP3 and IEC 60870-5-103 communication.

Industrial Applications

ABB lists pumps and conveyors, crushers and choppers, mixers and agitators, fans and aerators as typical drives for this relay, and that list maps closely onto plant in Oman. The ABB REM615 is a natural fit for crude transfer and water injection pumps in oil fields, seawater intake and high-pressure RO pumps in desalination plants on the Batinah coast, cooling water pumps at power stations, and induced-draft fans and crushers at cement and mining sites near Salalah and Duqm.

On large 6.6 kV and 11 kV motors the ABB REM615 normally works with a vacuum circuit breaker, while on large LV motors it can supervise a contactor feeder in the motor control centre. Seven Star LLC supplies the ABB REM615 with engineering support in Muscat, and we can coordinate the relay with feeder and transformer protection from the same 615 series for a consistent IEC 61850 station design.

Technical Specifications

These values come from the ABB REM615 product guide 1MRS756890 Rev. P (product version 5.0 FP1); confirm the final order code before purchase.

How to Order

To request a quotation for the ABB REM615, send Seven Star LLC the motor nameplate data, starting method, CT or sensor arrangement, auxiliary voltage and any RTD points you want to monitor. Our Muscat team will match the standard configuration and order code, confirm stock and delivery for Oman and the GCC, and support setting calculation and commissioning; the ABB product guide is available for download on this page. Related equipment we can quote includes the ABB REF615 feeder protection relay, the ABB VD4/P 12.06.32 vacuum circuit breaker for motor feeders and ABB M3BP process performance motors.

For the upstream transformer, see the ABB RET615 transformer protection relay.