Key Technical Specifications
| Parameter | Value |
|---|---|
| Motor Capacity | 500 kW to 2 MW |
| Auxiliary Supply | 100-240 V AC/DC or 110-250 V DC |
| Current Inputs | 4 precise channels (1A or 5A rated) |
| Protection ANSI | 49M, 51, 50, 46, 46R, 37, 51N, 66, 62BF |
| Temperature Input | RTD (6 inputs) or PTC Thermistors |
| Communication | SPA, Modbus RTU/ASCII, IEC 60870-5-103 |
| Disturbance Recorder | Up to 80 seconds, 4 analog + 8 digital channels |
| Event Logging | 100 time-stamped events (non-volatile) |
| Operating Temp | -25°C to +70°C |
| Dimensions | 177mm (W) x 160mm (H) x 149.3mm (D) |
Product Introduction
Motors don’t care about your maintenance schedule; they just burn out when the cooling fan fails or a bearing seizes. The ABB REM610 was built to stop that catastrophe before it starts, specifically for mid-sized asynchronous motors in the 500 kW to 2 MW range. I’ve installed these in pump stations and crusher drives where the ambient temp hits 45°C and the dust is thick enough to chew on. It calculates thermal stress based on actual current and temperature, not just a simple timer, which means it actually understands the motor’s real condition.Engineers stick with this relay because it integrates RTD monitoring directly into the protection logic. You get six RTD inputs to watch winding and bearing temps, and it blocks restarts if the motor is still too hot. The 80-second disturbance recorder is a lifesaver when you’re trying to figure out why a breaker tripped at 3 AM; it captures the waveform before the fault clears. One heads-up: the optical front port is handy, but the connector is fragile. Treat it like glass, or you’ll be buying a new faceplate.
Quality SOP & Tech Pitfalls
The Lab Report:
I don’t trust “tested” stickers. Every ABB REM610 we ship goes through a real workout. First, we do a visual inspection under magnification for cold solder joints or corroded terminals. Then it goes on our live test rack with a calibrated current injector. We push 120% load for 4 hours to verify thermal modeling accuracy and check that the RTD inputs track within ±1°C. Finally, we verify the Modbus map against the OEM spec sheet using a Fluke 115 and a laptop. If it fails, it gets scrapped. No exceptions.The Engineer’s Warning:
Here is where people mess up: Firmware version mismatches. I’ve seen guys swap a REM610 Rev B into a panel running Rev A logic, and the relay trips instantly on startup because the internal thermal curve constants changed. Always check the firmware version on the old unit before ordering. Another classic disaster: forgetting to photograph the DIP switches and jumper settings. I once watched a tech spend six hours chasing a “Phase Reversal” fault that was actually caused by a missing jumper on the CT polarity. Take a picture. Then take another one.
Installation & Configuration Guide
- Pre-Installation: ⚠️ LOCKOUT/TAGOUT. Verify zero energy. Wait 5 minutes for internal capacitors to discharge. Take high-res photos of the wiring, DIP switches, and jumper blocks. Do not skip this.
- Removal: Label every wire with a machine printer, not a Sharpie. Release the DIN rail clips gently; the plastic gets brittle after 10 years of heat cycling. If it sticks, use a flathead to lever it, don’t yank.
- Installation: Copy DIP/Jumper settings EXACTLY. This prevents 90% of startup failures. Slide the new ABB REM610 onto the rail until it clicks. Re-terminate wires to torque spec (usually 0.6 Nm for signal, check manual).
- Power-On & Testing: Apply 24V/110V aux power. Watch the LED sequence: Ready (Green) must be solid. If it flashes red, check your CT polarity. Connect your laptop via the optical port or rear RS-485. Download the existing configuration file. Verify the “Thermal Level” reads correctly before closing the breaker.
Compatible Replacement Models
| Model | Compatibility Tier | Notes |
|---|---|---|
| ABB REX615 | ✅ Drop-in Replacement | Official retrofit kit available. Same footprint, same wiring. Includes new connector kit. Best long-term fix. |
| ABB REM615 | ⚠️ Software Compatible | Same hardware chassis, but requires firmware update and logic recompile. Budget ~2 hours engineering time. |
| SEL 749/751 | ❌ Hardware Mod Required | Different dimensions, different wiring. Only choose this if you are doing a full panel upgrade. Do not swap 1:1. |
Frequently Asked Questions (FAQ)
Can I hot-swap the REM610 while the motor is running?
Absolutely not. The control wiring is tied to the breaker trip coil. If you pull this relay live and the internal contacts bounce, you could trip the motor or fry the relay. Shut it down. The 5-minute downtime to swap it safely saves you 5 weeks of motor rewind.Is the optical front port still reliable after 10 years?
Honestly? It’s hit or miss. The infrared window gets cloudy or the connector gets dusty. I always carry a cleaning swab and a spare optical cable. If it fails, use the rear RS-485 port or the optional fiber module. Don’t let a dirty port stop you from reading the fault recorder.Will my old CAP 501 software work with a new surplus unit?
Usually, but check the version. CAP 501 works for older firmware, but newer surplus stock might ship with firmware that prefers CAP 505 or the Relion 610 Configuration Tool. Download the latest free tool from ABB’s site before you go to the site. Don’t assume the old laptop will talk to the new relay.Does this relay support IEC 61850?
No. The REM610 is strictly Modbus, SPA, or IEC 60870-5-103. If your SCADA demands IEC 61850, you need to upgrade to the REX615. Don’t try to hack a gateway in front of this; it just adds another point of failure.What happens if aux power fails during a fault?
The REM610 has a non-volatile memory chip. It logs the fault and the last 5 events even if the power cuts out instantly. When power returns, the “Trip” LED will stay red, and the LCD will show the fault code. It’s designed to survive the blackout it’s protecting you from.How do I know if the RTD module is actually working?
Go to the measurement menu and check “RTD1-6.” If it reads -200°C or “Open,” your sensor is disconnected or the wire is broken. If it reads +999°C, you have a short. I’ve seen rodents chew through RTD cables in pump pits more times than I can count. Always verify the sensor, not just the relay.
