1SNA645004R0400 ABB RB121-230VUC Interface Relay – 230 V AC/DC, 1 SPDT, 6 A
The ABB 1SNA645004R0400, type RB121-230VUC (formerly RB121A-230VAC/DC), is a boxed interface relay from ABB’s R600 range. It has screw terminals and snaps onto a DIN rail. It provides electrical isolation, amplification and signal matching between PLCs, industrial PCs or fieldbus systems and the sensor/actuator level. The relay accepts a 230 V AC/DC control supply on a single coil and switches loads up to 6 A at 250 V AC through one changeover (SPDT) contact. Because the relay is soldered inside its 6 mm housing, it resists vibration and shock, and it cannot come loose or be swapped for the wrong relay.
Key Features of the ABB RB121-230VUC
- Universal 230 V AC/DC coil (50/60 Hz), so one part number covers both AC and DC control circuits
- Slim 6 mm housing, 70 mm high and 75 mm deep, which saves panel space in compact cabinets
- Green LED shows that control voltage is applied
- Grey UL 94 V0 flame-retardant housing, IP20 protection
- Lloyd’s Register (LR) marine approval for the R600 range
- Jumper bars available for fast common wiring across multiple modules
Technical Specifications – 1SNA645004R0400
| Parameter | Value |
|---|---|
| Manufacturer | ABB |
| Order code | 1SNA645004R0400 |
| Type | RB121-230VUC / RB121A-230VAC/DC |
| Product range | R600 boxed interface relays |
| Rated control voltage | 230 V AC/DC, 50/60 Hz |
| Voltage tolerance | ±10 % AC; +10 % / −15 % DC |
| Coil power / current | 0.8 W / 3.5 mA |
| Drop-out voltage (20 °C) | 27 V |
| Output | 1 changeover contact (1 SPDT), high level |
| Switching voltage | 12 V – 250 V AC |
| Switching current | 10 mA – 6 A |
| Switching capacity AC1 / DC1 | 0.6 VA – 1500 VA / 0.6 W – 140 W |
| AC15 / DC13 (24 V) | 3 A / 1 A |
| Mechanical life | 10⁷ operations |
| Electrical life | 10⁵ operations (AC15) |
| Operate / release time | 7 ms / 16 ms |
| Insulation coil–contact | 4000 V RMS |
| Operating temperature | −20 °C to +70 °C |
| Storage temperature | −40 °C to +80 °C |
| Connection | Screw clamp; solid 0.2–4 mm², stranded 0.22–2.5 mm² (24–12 AWG) |
| Stripping length / torque | 9 mm / 0.4–0.6 Nm |
| Width / weight | 6 mm / 0.02 kg |
Typical Applications
The RB121-230VUC fits control panels where 230 V signals must drive or be isolated from PLC I/O. Typical uses include machine building, conveyor and packaging lines, HVAC control and marine installations. Its 6 A contact can switch contactor coils, solenoid valves, signal lamps and other auxiliary loads directly from a mains-level control signal.
Compatible ABB R600 Accessories
- SC 612 jumper bar, 10 poles
- BADH / BADL end sections and BAM2 separator end section
- FC2 test plug, 2 mm diameter
- RC65 and RC610 markers
Other Versions in the ABB RB121 Family
- 1SNA645001R0300 – RB121A, 24 V AC/DC
- 1SNA645002R0400 – RB121A, 48–60 V AC/DC
- 1SNA645003R0500 – RB121A, 115 V AC/DC
- 1SNA645008R1200 – RB121A, 230 V AC/DC, low-level contact (1 mA – 6 A)
- 1SNA645504R0000 – RBR121A, 230 V AC/DC, spring clamp version
Buy ABB 1SNA645004R0400 from Atlantech Drives
Order the ABB 1SNA645004R0400 with fast worldwide shipping. Our commercial team can advise on pricing, volumes and lead times for single units or panel-build quantities. Request a quote today and get a quick response.
