Description
ABB REM610C55HCNN02 Motor Protection Relay
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | ABB |
| Product Family | Relion 610 |
| Relay Type | REM610 Motor Protection Relay |
| Exact Order Code | REM610C55HCNN02 |
| Product Version | C |
| Phase Current Rating | 5 A |
| Earth-Fault Current Rating | 5 A |
| Rated Frequency | 50/60 Hz ±5 Hz |
| Auxiliary Supply Class | H |
| Auxiliary Voltage | 100/110/120/220/240 VAC or 110/125/220/250 VDC |
| Phase Current Measuring Range | 0–50 × In |
| Earth-Fault Measuring Range | 0–8 × In |
| Phase Current Inputs | 3 |
| Earth-Fault Input | 1 |
| Digital Inputs | 2 standard; additional inputs depend on optional RTD module |
| Power Outputs | 3 heavy-duty trip contacts |
| Signal Outputs | 2 signal contacts |
| Front Communication | Infrared / optical |
| Rear Communication | Optional communication module |
| Communication Protocols | SPA, IEC 60870-5-103, or Modbus depending on rear interface |
| Disturbance Recorder | 4 analog channels + up to 8 user-selectable digital channels |
| Dimensions | 177 mm × 177 mm × 149.3 mm frame/case depth configuration |
| Weight | Approx. 3.5 kg complete relay |
| Product Status | Legacy / inactive |
The REM610 technical reference specifies four current inputs, including three phase-current inputs and an earth-fault current input. It supports both 1 A and 5 A versions; the 55 configuration in this order code corresponds to 5 A phase and 5 A earth-fault inputs.
Protection Functions
REM610 is designed around motor protection rather than simple overcurrent tripping. Its documented functions include:
- Thermal overload protection
- Motor start-up supervision
- Running stall protection
- Short-circuit / phase overcurrent protection
- Earth-fault protection
- Phase unbalance / negative-sequence protection
- Loss-of-phase protection
- Undercurrent protection
- Circuit-breaker failure protection
- Restart inhibit and accumulated motor start supervision
- Optional motor temperature monitoring through RTD/thermistor hardware
ABB specifically describes REM610 as suitable for fault conditions occurring during motor startup, normal running, idling, and cooling after shutdown.
REM610C55HCNN02
Product Introduction
The ABB REM610C55HCNN02 is a multifunction motor protection relay from ABB’s Relion 610 family. It is intended primarily for medium and large asynchronous motors and combines protection, measurement, supervision, event recording, disturbance recording, and control functions in one relay. It can also be applied to feeder cables and power transformers where thermal overload and overcurrent protection are required.
The C55H portion of the ordering code is particularly important when replacing an installed unit: this configuration uses 5 A phase-current and 5 A earth-fault inputs together with the high-voltage auxiliary supply class. The rear communication interface is not determined simply by the REM610 family name; the installed communication option must be checked separately.
Application Scenarios & Field Pitfalls — Engineer’s Perspective
REM610 is commonly found in motor protection panels for pumps, fans, compressors, mills, crushers, and other industrial motor-driven equipment. Its protection logic is closely tied to the motor’s rated current, starting behavior, thermal characteristics, CT ratios, and protection coordination.
Typical Applications
- Medium-voltage asynchronous motors — primary application for motor protection and supervision.
- Industrial motor feeders — provides phase overcurrent, earth-fault, thermal, and unbalance protection.
- Motor control switchgear — can operate with circuit-breaker- or contactor-controlled motor drives.
- Feeder and transformer protection — applicable where thermal overload and overcurrent functions are required.
Field Pitfalls
Verify the CT secondary rating before replacement. REM610C55HCNN02 is a 5 A configuration. Replacing it with a 1 A variant is not a cosmetic change; the current-input scaling and protection settings are different.
Check the auxiliary supply code. The H supply class supports 100–240 VAC and 110–250 VDC nominal supply ranges. The L-supply variants use 24–60 VDC instead. A relay with the wrong supply configuration should not be treated as an interchangeable spare.
Do not assume a rear communication protocol from the base model. provides a front infrared interface, while rear communications require an optional module. The available rear interfaces include fiber-optic or RS-485 variants, with SPA, IEC 60870-5-103, or Modbus depending on configuration.
Review protection settings after hardware replacement. Motor thermal capacity, starting time, CT ratio, earth-fault settings, restart inhibition, and protection-stage delays are application-specific. A replacement relay should not simply inherit assumptions from another motor feeder.
Account for the legacy status. ABB identifies as an inactive product since 2017. For an operating plant, availability of an exact spare, configuration compatibility, and a controlled migration strategy deserve attention before the existing relay becomes a forced replacement.
Related Products
- — same motor protection relay family; exact hardware configuration must be checked.
- REM615 — later ABB motor protection platform with a different hardware and engineering architecture.
- REF610 — feeder protection relay in the same 610 family; designed around feeder applications rather than dedicated motor protection.
- REU610 — voltage protection relay in the Relion 610 family.
- RET610 — transformer protection relay in the 610 family.
- REC610 — control/synchronizing-oriented member of the 610 family.
- PCM600 — ABB IED engineering and management environment associated with ABB protection and control products.
The 610-series relays share a plug-in architecture, but same-family does not mean direct interchangeability. Application function, current-input rating, auxiliary supply, communication option, and installed settings all need to match.
Procurement Note
For ABB REM610C55HCNN02, I would specify the complete order code rather than purchasing simply as “.”
The critical replacement checks are:
- REM610C55HCNN02 exact order code
- 5 A phase-current inputs
- 5 A earth-fault input
- H auxiliary supply
- Installed rear communication option
- RTD/thermistor hardware, if required by the motor protection scheme
- Existing protection settings and CT ratios
- Plug-in unit and case compatibility
ABB’s official documentation confirms that the order number identifies the relay hardware configuration and that the family is now a legacy product.
Procurement recommendation: for a legacy installation, prioritize an exact hardware match. If an exact spare is unavailable, do not substitute another configuration until the CT rating, auxiliary supply, communication hardware, I/O configuration, and protection settings have been compared.
