Modular residual current devices of type MRCDB425 are designed for AC/DC sensitive differential and residual current measurement in earthed TN and TT networks. The devices can be used as an additional protective measure for the following protection goals, among others:
A modular residual current device in accordance with product standard DIN EN 60947-2 Annex M must be operated together with a suitable measuring current transformer (CTUB102-CTBCxxx(P)) and a circuit breaker with undervoltage release, which switches off under load within a maximum of 20 ms.

Modular residual current devices of type MRCDB425 are designed for AC/DC sensitive differential and residual current measurement in earthed TN and TT networks. The devices can be used as an additional protective measure for the following protection goals, among others:
A modular residual current device in accordance with product standard DIN EN 60947-2 Annex M must be operated together with a suitable measuring current transformer (CTUB102-CTBCxxx(P)) and a circuit breaker with undervoltage release, which switches off under load within a maximum of 20 ms.
Special features
Residual current measurement
Response value monitoring
Display and operation
Interfaces
Test output for external connected measuring current transformer monitoring
| Type | Supply voltage US | Art. No. |
|---|---|---|
| MRCDB425-D-2 | DC 24 V; AC/DC 100…240 V | B84606030 |
| MRCDB425-L-2 | DC 24 V; AC/DC 100…240 V | B84605030 |
Accessories
| Type | Art. No. |
|---|---|
| Sealable transparent cover (spare part) | B80609299 |
External power supply
| Type | Rated input voltage UIN | Rated voltage | Art. No. |
|---|---|---|---|
| STEP-PS/1 AC/24 DC/0.5 | AC 85…264 V, 45…65 Hz; DC 95…250 V | DC 24 V | B94053110 |
| STEP-PS/1 AC/24 DC/1.75 | AC 85…264 V, 45…65 Hz; DC 95…250 V | DC 24 V | B94053111 |
| STEP-PS/1 AC/24 DC/4.2 | AC 85…264 V, 45…65 Hz; DC 95…250 V | DC 24 V | B94053112 |
External measuring current transformers
| Type | Shielding | Inside diameter (mm) | Art. No. |
|---|---|---|---|
| CTUB102-CTBC20 | - | ø 20 | B78120011 |
| CTUB102-CTBC20P | x | ø 20 | B78120021 |
| CTUB102-CTBC35 | - | ø 35 | B78120013 |
| CTUB102-CTBC35P | x | ø 35 | B78120023 |
| CTUB102-CTBC60 | - | ø 60 | B78120015 |
| CTUB102-CTBC60P | x | ø 60 | B78120025 |
| CTUB102-CTBC120 | - | ø 120 | B78120017 |
| CTUB102-CTBC120P | x | ø 120 | B78120027 |
| CTUB102-CTBC210 | - | ø 210 | B78120019 |
| CTUB102-CTBC210P | x | ø 210 | B78120029 |
| Nome | Tipo | Dimensione | Lingua | Timestamp | D-/B-Numero |
|---|---|---|---|---|---|
| MRCDB425-D | Data sheet | 3.7 MB | DE | 2026/02/2727.02.2026 | D00495 |
| MRCDB425-D | Data sheet | 3.7 MB | EN | 2026/02/2727.02.2026 | D00495 |
| MRCDB425-D | Manuali di istruzioni | 5.8 MB | DE | 2026/01/2222.01.2026 | D00495 |
| MRCDB425-D | Manuali di istruzioni | 5.8 MB | EN | 2026/01/2222.01.2026 | D00495 |
| MRCDB425-D | Quickstarts | 1.1 MB | DE | 2025/08/0404.08.2025 | D00495 |
| MRCDB425-D | Quickstarts | 1.1 MB | EN | 2025/08/0404.08.2025 | D00495 |
| MRCDB425-L | Data sheet | 3.4 MB | DE | 2026/02/2727.02.2026 | D00497 |
| MRCDB425-L | Data sheet | 3.4 MB | EN | 2026/02/2727.02.2026 | D00497 |
| MRCDB425-L | Manuali di istruzioni | 7.3 MB | DE | 2026/01/2222.01.2026 | D00497 |
| MRCDB425-L | Manuali di istruzioni | 7.4 MB | EN | 2026/01/2222.01.2026 | D00497 |
| MRCDB425-L | Quickstarts | 1.1 MB | DE | 2025/08/0404.08.2025 | D00497 |
| MRCDB425-L | Quickstarts | 1.1 MB | EN | 2025/08/0404.08.2025 | D00497 |