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Phoenix Contact CBM E8 24DC/0.5-10A NO-R (Part Number 2905744) is a multi-channel electronic circuit breaker specifically designed for 24V DC low-voltage circuits. Its core functionality employs active current limiting technology to provide dual protection against overloads and short circuits for 8 independent loads. Widely applicable in industrial automation control circuits and equipment power distribution scenarios, it ensures stable operation of low-voltage loads.
Protection Targets and Methods: Independently protects 8 channels of 24V DC loads. Rapidly responds to overloads (current exceeding set thresholds) and short-circuit faults via active current limiting, preventing equipment damage from fault propagation. Compared to traditional mechanical circuit breakers, electronic protection offers faster response times and longer lifespan with no contact wear.
Current Adjustment Range: Flexible single-channel rated current settings from 0.5A to 10A accommodate diverse 24V DC loads (e.g., sensors, small actuators, indicator lights), meeting varied load protection requirements.
Protection Auxiliary Functions: Features a nominal current assistant to simplify current parameter setting and calibration. Also supports electronic locking to secure configured current parameters, preventing tampering from accidental operation and enhancing operational safety.
Mounting Method: Utilizes industrial-standard DIN rail mounting, compatible with common EN 60715 DIN rails (e.g., NS 35/7.5). Direct integration into control cabinets saves installation space and facilitates coordinated layout with other power distribution and protection equipment (e.g., power modules, terminal blocks).
Circuit Compatibility: Designed exclusively for 24V DC low-voltage circuits. Features a "Normally Open (NO-R)" design (circuit remains open by default; closes only when normal power supply is present and protection conditions are met). Must be matched with load circuits of corresponding voltage ratings to prevent overvoltage operation.
Status Monitoring and Indication: Typically equipped with LED status indicators (refer to official specifications), providing visual feedback on each load circuit's status—including "Normal Operation," "Overload," and "Short Circuit." This enables field maintenance personnel to quickly identify faulty circuits and enhance repair efficiency.
Industrial Environment Compatibility: As industrial-grade equipment, its enclosure and internal circuit design withstand industrial temperature fluctuations (typically -25°C to +60°C; refer to official specifications) and electromagnetic interference, ensuring stable protection performance in harsh conditions.
Wiring and Integration: Likely incorporates Phoenix Contact's classic convenient wiring design (e.g., plug-in or spring-clamp terminals), enabling tool-free wire fixation. This simplifies installation while reducing risks of poor contact due to loose connections, meeting the rapid wiring demands of industrial sites.
| Product type | Device circuit breakers |
| Product family | CBM |
| Type | DIN rail module, one-piece |
| Number of positions | 1 |
| No. of channels | 8 |
| Protection class | III |
| Pollution degree | 2 |
| Operating voltage | 18 V DC ... 30 V DC |
| Rated voltage | 24 V DC |
| Rated current IN | max. 80 A DC (for double supply IN+ with at least 2 x 6 mm²) max. 70 A DC (for UL 2367) |
| Rated current IN (adjustable) | 0.5 / 1 / 2 / 4 / 6 / 10 A DC (adjustable per output channel) |
| Rated current (pre-adjusted) | 0.5 A |
| Rated surge voltage | 0.5 kV |
| Tripping method | E (electronic) |
| Feedback resistance | max. 35 V DC |
| Required backup fuse | Only required if Imax of the power supply > the short-circuit switching capacity. Integrated failsafe element. |
| Short-circuit switching capacity | 300 A |
| Dielectric strength | max. 30 V DC (Load circuit) |
| Active current limitation | typ. 2.0 x IN (0.5 - 1 A) typ. 1.5 x IN (2 - 10 A) |
| Fuse | electronic |
| Efficiency | > 99 % |
| Closed circuit current I0 | typ. 50 mA |
| Power dissipation | 1.2 W (No-load operation) 17.2 W (Nominal operation) |
| Module initialization time | 3.3 s |
| Waiting time after switch off | 10 s (at overload / short circuit) |
| Measuring tolerance I | typ. 40 % (0.5 A ... 1 A) typ. 10 % (2 A ... 10 A) |
| Temperature derating | 40 A DC (at 70°C (65°C for UL 2367)) 50 A DC (at 60 °C) 60 A DC (at 50 °C) 70 A DC (at 40 °C) 80 A DC (at 40 °C) 70 A DC (at 40 °C for UL 2367) |
| MTBF (IEC 61709, SN 29500) | 1304293 h (at 25 °C) 858501 h (at 40 °C) 440048 h (at 60 °C) |
| Fail-safe element | 15 A DC (per output channel) |
| Contact switching type | without electrical isolation |
| Connection method | Push-in connection |
| Stripping length | 18 mm |
| Conductor cross-section rigid | 0.75 mm² ... 16 mm² |
| Conductor cross-section AWG | 20 ... 4 |
| Conductor cross-section flexible (with ferrule/plastic sleeve) | 0.75 mm² ... 10 mm² |
| Conductor cross-section flexible (with ferrule/no plastic sleeve) | 0.75 mm² ... 16 mm² |
| Width | 41 mm |
| Height | 130 mm |
| Depth | 121 mm (incl. DIN rail 7.5 mm) |
| Color | light gray (RAL 7035) gray (RAL 7042) |
| Material | PC, PA 6.6, PBT-FR17, POM |
| Flammability rating (UL 94) | V-0 |
| Degree of protection | IP20 |
| Ambient temperature (operation) | -25 °C ... 70 °C (Startup at -40 C type-tested) -25 °C ... 65 °C (for UL 2367) |
| Ambient temperature (storage) | -40 °C ... 80 °C |
| Altitude | ≤ 6000 m (amsl) |
| Humidity test | 240 h, 95 % RH, 40 °C |
| Shock (operation) | 30g (IEC 60068-2-27, Test Ea) |
| Vibration (operation) | 5 Hz ... 24.9 Hz (Amplitude ±1.6 mm) 24.9 Hz … 150 Hz (Acceleration 4g) |
| Mounting type | DIN rail: 35 mm |
Phoenix Contact CBM E8 24DC/0.5-10A NO-R - Electronic circuit breaker 2905744
| Item number | 2905744 |
| Packing unit | 1 pc |
| Minimum order quantity | 1 pc |
| Weight per piece (including packing) | 306.05 g |
| Weight per piece (excluding packing) | 303.8 g |
| Customs tariff number | 85362010 |
| Country of origin | DE |
It is an 8-channel electronic circuit breaker designed to provide active current limiting, overload, and short-circuit protection for 24V DC low-voltage loads in industrial automation and power distribution applications.
Yes, the rated current for each output channel can be configured independently, with adjustments ranging from 0.5A up to 10A to suit different load characteristics.
It is designed for DIN rail mounting and is compatible with standard 35 mm DIN rails (such as EN 60715 NS 35/7.5), allowing for seamless integration into industrial control panels.
This device features a Push-in connection technology, allowing for quick, secure, and tool-free installation of conductors.
The "Normally Open" (NO-R) configuration means the contact circuit remains open by default. It closes to supply power only when proper input voltage is verified and all operating safety conditions are successfully met.
