Relion 615 Series
ABB Relion 615 Series Protection Relays
When application-specific protection is required for feeders, motors, two-winding transformers or two-terminal lines, ABB Relion 615 Series provides REF615, REM615, RET615 and RED615 on a common plug-in platform.
About this product
ABB Relion 615 Series combines application-specific protection, control, measurement and supervision functions on a common withdrawable plug-in platform. The Forvis Trade scope consolidates four models — REF615 feeder protection, REM615 motor protection, RET615 transformer protection, and RED615 line differential protection — on one canonical family page.
Platform structure
- REF615: feeder protection for overhead lines and cable feeders in radial, looped and meshed distribution systems.
- REM615: motor protection for asynchronous motors and drives in manufacturing and process industries.
- RET615: transformer protection for two-winding power transformers, including distribution, unit and step-up applications.
- RED615: line differential protection for two-terminal overhead lines and cable sections, with a relay installed at each end exchanging measurement and binary data over a dedicated communication channel.
All four models share the same withdrawable case and are engineered with the same tools; what differs is the protection function set available per standard configuration.
Model selection
REF615 is suited to feeders requiring directional protection, auto-reclosing, synchrocheck, or advanced earth-fault and fault-location methods, depending on the selected standard configuration — functions include phase overcurrent (50/51), earth-fault (50N/51N), directional overcurrent (67), directional earth-fault (67N), negative-sequence overcurrent (46), thermal overload (49), breaker failure (50BF), auto-reclosing (79), under/overvoltage (27/59), frequency (81), and synchrocheck (25). Selected configurations add sensor inputs and optical arc detection.
REM615 should be selected for asynchronous-motor protection needing thermal overload (49M), negative-sequence current (46), undercurrent (37), starting and locked-rotor supervision (48/51LR), starts-per-hour supervision (66), phase overcurrent (50/51), earth-fault (50N/51N), breaker failure (50BF), and, in applicable configurations, machine differential protection (87M). RTD/mA inputs are available for temperature and process monitoring when the corresponding module is selected.
RET615 fits two-winding transformer protection needing stabilized and instantaneous differential protection (87T), restricted earth-fault (87N/64), phase overcurrent (50/51), earth-fault (50N/51N), overexcitation (24), thermal overload (49), breaker failure (50BF), inrush restraint, and vector-group compensation, with optional transformer-monitoring inputs.
RED615 is the right choice when a defined two-terminal line or cable section needs line differential protection (87L) plus phase overcurrent (50/51), earth-fault (50N/51N), directional earth-fault (67N), negative-sequence overcurrent (46), breaker failure (50BF), and auto-reclosing (79). The communication channel and hardware must be selected to match the project's topology.
Engineering and communication
The 615 Series is engineered with ABB PCM600. Depending on the relay and communication module selected, the platform supports IEC 61850 Edition 1 and Edition 2, GOOSE messaging, IEC 61850-9-2 LE process bus, IEC 60870-5-103, Modbus, and DNP3. Selected Ethernet modules support PRP or HSR network redundancy.
Typical applications
- Radial, looped, and meshed distribution feeders
- Asynchronous motor drives in manufacturing and process plants
- Two-winding distribution, unit, and step-up transformers
- Two-terminal cable or overhead-line sections requiring unit protection
- Retrofit and modernization of legacy electromechanical or first-generation numerical relays
Product lifecycle and REX615
ABB identifies REX615 as the successor to the 615 and 620 Series and states no further releases are planned for either series. This page should serve both existing-system support and application identification — for new projects, compare the required 615 model and configuration against REX615 before the specification is finalized. The exact standard configuration, analog inputs, digital inputs and outputs, communication module, and arc sensors must be verified against the order code.
Technical Specifications
| Applications | Feeder, motor, two-winding transformer and two-terminal line protection |
| Platform | Application-specific Relion 615 Series withdrawable plug-in platform |
| Communication | IEC 61850, GOOSE, IEC 60870-5-103, Modbus and DNP3 depending on model and module |
| IEC 61850 | Edition 1 and Edition 2; selected configurations support IEC 61850-9-2 LE, PRP and HSR |
| Sensor Support | Conventional instrument transformers or sensors depending on model and configuration |
| Arc-Flash Protection | Available on selected models and configurations |
| Mounting | Withdrawable plug-in unit for flush mounting |
| Engineering Software | ABB PCM600 |
| Product Status | Mature platform; ABB identifies REX615 as the next step and states that no further 615 Series releases are planned |
Model Selection
| Model | Relay type | Main application | Protection approach | When to select |
|---|---|---|---|---|
| REF615 | Application-specific withdrawable feeder protection relay | Feeder protection and bay control | Wide neutral earthing compatibility, advanced earth-fault methods, fault location and sensor options | Should be selected when an overhead line or cable feeder requires protection, control and IEC 61850 integration together |
| REM615 | Application-specific withdrawable motor protection relay | Asynchronous motor protection | Motor thermal model, starting and locked-rotor supervision, RTD/mA and machine differential options | Should be selected when critical or comprehensive motor protection, temperature monitoring and IEC 61850 integration are required |
| RET615 | Application-specific withdrawable transformer protection relay | Two-winding transformer protection | Transformer differential main protection, vector-group compensation and restricted earth-fault options | Should be selected for two-winding distribution, step-up or unit transformers requiring main and backup protection together |
| RED615 | Application-specific withdrawable line differential relay | Two-terminal line differential protection | Phase-segregated two-terminal line differential protection with dual signal transfer | Should be selected when a defined two-terminal cable or overhead-line section requires fast and selective zone protection |
Hardware and Integration
| Model | Measurement inputs | Digital I/O | Sensor support | IEC 61850 | Special integration |
|---|---|---|---|---|---|
| REF615 | 3-phase CT and VT inputs | Up to 16 BI, 10 BO | Conventional CT/VT | Edition 1 and Edition 2; selected process-bus and redundancy functions | Advanced earth-fault protection and fault location depending on configuration |
| REM615 | 3-phase CT inputs; optional RTD/mA module for temperature or process signals | Up to 16 BI, 10 BO | Conventional CT; RTD/mA module optional | Edition 1 and Edition 2 depending on product version | Motor start profiles, condition monitoring and machine differential option |
| RET615 | 3-phase CT and VT inputs; optional RTD/mA module for temperature or tap-position signals | Up to 16 BI, 10 BO | Conventional CT/VT; RTD/mA module optional | Edition 1 and Edition 2 depending on product version | Vector-group and CT-ratio compensation, inrush restraint and transformer monitoring |
| RED615 | 3-phase CT and VT inputs, withdrawable case | Up to 16 BI, 10 BO | Conventional CT/VT | Edition 1 and Edition 2 depending on product version | Binary signal transfer and optional transformer in-zone inrush restraint |
Protection Functions
| Model | Protection scope | Main functions |
|---|---|---|
| REF615 | Overcurrent and earth-fault feeder protection in different neutral arrangements | 50/51, 50N/51N, 67, 67N, 46, 49, 50BF, 79, 25, 27/59/81 |
| REM615 | Electrical, thermal and start-up protection for industrial motors | 49M, 46, 37, 48/51LR, 66, 50/51, 50N/51N, 50BF, 87M, depending on configuration |
| RET615 | Main and backup protection for distribution, unit and step-up transformers | 87T, 87N/64, 50/51, 50N/51N, 24, 49, 50BF |
| RED615 | Unit protection for cable and overhead-line sections with dedicated end-to-end communication | 87L, 50/51, 50N/51N, 67N, 46, 50BF, 79 |
Ordering Options
| Article Code | Hardware Class | Main Application | Protection Scope | Protection Functions | Measurement Inputs | Digital Inputs and Outputs | Sensor Support | Communication | IEC 61850 | Arc-Flash Protection | Mounting | Special Functions | Product Status | selection differentiator | selection note | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| REF615 | Application-specific withdrawable feeder protection relay | Feeder protection and bay control | Overcurrent and earth-fault feeder protection in different neutral arrangements | 50/51, 50N/51N, 67, 67N, 46, 49, 50BF, 79, 25, 27/59/81 | 3-phase CT and VT inputs | Up to 16 BI, 10 BO | Conventional CT/VT | IEC 61850, IEC 60870-5-103, Modbus and DNP3 depending on module | Edition 1 and Edition 2; selected process-bus and redundancy functions | Available in selected configurations | Withdrawable plug-in, flush mounted | Advanced earth-fault protection and fault location depending on configuration | Mature platform; compare with REX615 | Wide neutral earthing compatibility, advanced earth-fault methods, fault location and sensor options | Should be selected when an overhead line or cable feeder requires protection, control and IEC 61850 integration together | |
| REM615 | Application-specific withdrawable motor protection relay | Asynchronous motor protection | Electrical, thermal and start-up protection for industrial motors | 49M, 46, 37, 48/51LR, 66, 50/51, 50N/51N, 50BF, 87M, depending on configuration | 3-phase CT inputs; optional RTD/mA module for temperature or process signals | Up to 16 BI, 10 BO | Conventional CT; RTD/mA module optional | IEC 61850, IEC 60870-5-103, Modbus and DNP3 depending on module | Edition 1 and Edition 2 depending on product version | Configuration dependent | Withdrawable plug-in, flush mounted | Motor start profiles, condition monitoring and machine differential option | Mature platform; compare with REX615 | Motor thermal model, starting and locked-rotor supervision, RTD/mA and machine differential options | Should be selected when critical or comprehensive motor protection, temperature monitoring and IEC 61850 integration are required | |
| RET615 | Application-specific withdrawable transformer protection relay | Two-winding transformer protection | Main and backup protection for distribution, unit and step-up transformers | 87T, 87N/64, 50/51, 50N/51N, 24, 49, 50BF | 3-phase CT and VT inputs; optional RTD/mA module for temperature or tap-position signals | Up to 16 BI, 10 BO | Conventional CT/VT; RTD/mA module optional | IEC 61850, IEC 60870-5-103, Modbus and DNP3 depending on module | Edition 1 and Edition 2 depending on product version | Available in selected configurations | Withdrawable plug-in, flush mounted | Vector-group and CT-ratio compensation, inrush restraint and transformer monitoring | Mature platform; compare with REX615 | Transformer differential main protection, vector-group compensation and restricted earth-fault options | Should be selected for two-winding distribution, step-up or unit transformers requiring main and backup protection together | |
| RED615 | Application-specific withdrawable line differential relay | Two-terminal line differential protection | Unit protection for cable and overhead-line sections with dedicated end-to-end communication | 87L, 50/51, 50N/51N, 67N, 46, 50BF, 79 | 3-phase CT and VT inputs, withdrawable case | Up to 16 BI, 10 BO | Conventional CT/VT | Dedicated line differential channel plus IEC 61850 station communication; other protocols module dependent | Edition 1 and Edition 2 depending on product version | Configuration dependent | Withdrawable plug-in, flush mounted | Binary signal transfer and optional transformer in-zone inrush restraint | Mature platform; compare with REX615 | Phase-segregated two-terminal line differential protection with dual signal transfer | Should be selected when a defined two-terminal cable or overhead-line section requires fast and selective zone protection |
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