How to Select an RCD: Sensitivity, Type and Poles Checklist
A step-by-step checklist for selecting RCD sensitivity, type, poles and rated current, matched to the earthing system, IEC standards, and special cases like EV...
The ABB RD2 (SKU: 2CSM142120R1201) is a Type A residual current monitoring relay designed to continuously monitor insulation integrity and earth leakage currents in AC electrical installations. Rated for residual currents up to 2000 mA across a supply voltage range of 230–400 V AC, the RD2 provides reliable early-warning protection for industrial control panels and distribution systems, enabling preventive maintenance before a fault escalates to a trip event.
The ABB RD2 residual current monitoring relay is widely deployed in industrial automation, commercial building management, and infrastructure applications where continuous leakage current surveillance is critical. Typical applications include monitoring of motor feeder circuits, IT and TN earthing systems, uninterruptible power supplies (UPS), data centre power distribution, HVAC control panels, and process manufacturing lines where unplanned shutdowns must be avoided. By providing an early warning output before the leakage current reaches the disconnection threshold, the RD2 enables maintenance teams to schedule corrective action without interrupting production.
| Type of Residual Current | Type A |
|---|---|
| Function | For AC-current system |
| Current Rating | Response value amperage 1 2000 ... 2000 mA |
| Number of Contacts | 1 |
| Delay Time (τ) | Delay-On Energization, Maximum, Permitted 5 s, Delay-On Energization, Minimum, Adjustable 0.3 s |
| Filter Option | no frequency filter |
| Options Provided | Pre-alarm threshold: no |
| Rated Voltage (Ur) | 400...400 V |
|---|---|
| Rated Operational Voltage | 230 ... 400 V AC |
| Rated Control Supply Voltage (Us) | (50 Hz) 400...400 V, (60 Hz) 400...400 V |
| Rated Frequency (f) | 50 … 60 Hz |
| Power Loss | Total 3.4 W |
| Number of Contacts CO | 1 |
| Number of Contacts NC | 0 |
| Number of Contacts NO | 0 |
| RoHS Information | Following EU Directive 2011/65/EU |
|---|---|
| RoHS Date | 20190722 |
| REACH Information | False - does not contain substances > 0.1 mass percentage |
| REACH Date | 20240429 |
| WEEE Category | 5. Small Equipment (No External Dimension More Than 50 cm) |
| WEEE B2C / B2B | Business To Business |
| Part number | 2CSM142120R1201 |
|---|---|
| Type designation | RD2 |
| Brand | ABB |
| Condition | New, factory sealed |
| Source | ABB and its authorised distributors |
| Warranty | Manufacturer warranty |
| EAN | 8012542058007 |
| ETIM class | EC001445 |
| eCl@ss | 27371809 |
| Package Level 1 Units | box 1 piece |
| Package Level 1 Gross Weight | 0.15 kg |
| Product Net Width | 35 mm |
|---|---|
| Product Net Height | 0.085 m |
| Product Net Depth / Length | 65 mm |
| Product Net Weight | 0.105 kg |
| Instructions and Manuals | 0400 - 9924 |
|---|---|
| Mounting Type | DIN-Rail |
| ETIM 10 | EC001445 - Residual current monitoring relay |
|---|---|
| UNSPSC | 39121601 |
| eClass | V11.0 : 27371809 |
| Standards | IEC EN 62020 |
| Shipping weight | 0.105 kg |
|---|---|
| Ships from | Türkiye |
| Dispatch | 11 Nov |
| Stock | In stock |
Source: manufacturer data · Last verified: 30 Oct 2026
No documents are on file for this part yet.
Ask us for the datasheetThe rated operational voltage of RD2 is 230–400 V AC.
The tariff (HS) code on file for RD2 is 853649.
The EAN (GTIN) of RD2 is 8012542058007.
RD2 ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
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