Digital guide
You are here:
B&R ECPT81-0
Product Introduction:
The B&R ECPT81-0 is a 24V DC power supply module designed specifically for the B&R Automation PC 910 series of compact controllers (including ECFP128-0 and related modules). It converts AC mains (100-240V AC) to a regulated 24V DC output to power the controller and connected X20 I/O modules. It features high efficiency, low ripple, and built-in protection circuits for reliable operation in industrial environments.
Detailed content
Technical Specifications:
| Parameter | Value |
|---|---|
| Input Voltage | 100V AC to 240V AC (single-phase), 50/60 Hz |
| Output Voltage | 24V DC (regulated) |
| Output Current | 5A (120W max) |
| Output Power | 120W |
| Efficiency | ≥ 88% (at full load) |
| Ripple and Noise | ≤ 50 mV peak-to-peak |
| Output Voltage Accuracy | ±2% (±0.48V) |
| Line Regulation | ±0.5% |
| Load Regulation | ±1% |
| Protection Features | Overcurrent (OCP), Overvoltage (OVP), Short-circuit (SCP), Overtemperature (OTP) |
| Operation Temperature | -25°C to +70°C |
| Protection Class | IP20 |
| Dimensions (W×H×D) | 22.5 mm × 90 mm × 120 mm |
| Weight | Approx. 250 g |
| Conformity | CE, UL, CSA, ATEX Zone 2 |
| Cooling | Convection (fanless) |
Functional Features:
- Universal AC input (100-240V AC) — works worldwide without reconfiguration
- High efficiency (≥ 88%) — minimizes heat generation and energy cost
- Low output ripple (≤ 50 mV) — ensures clean power for sensitive analog I/O and controllers
- Four-layer protection: OCP, OVP, SCP, OTP — comprehensive fault protection
- LED indicators: Power OK, Fault
- DIN rail TS35 mounting — fits standard automation cabinets
Structural Characteristics:
- Snap-in DIN rail TS35 mounting
- Spring-loaded push-in terminals: 0.14 mm² to 4 mm² wire
- Housing: glass-fiber reinforced polyamide (PA66-GF30), UL94 V-0 rated
- Ventilation slots on top and bottom for natural convection cooling
Working Principle:
The ECPT81-0 uses a high-frequency switch-mode power supply (SMPS) topology. The AC mains is rectified to DC, then chopped at high frequency (typically 100-300 kHz) by a MOSFET switch. The high-frequency AC is transformed by a ferrite core transformer to the required voltage level, then rectified and filtered to produce a stable 24V DC output. A PWM controller IC regulates the output voltage by adjusting the duty cycle based on feedback from the output. The protection circuits monitor output current, voltage, and internal temperature, shutting down the converter if any parameter exceeds safe limits.
Advantages & Highlights:
- Universal input voltage — one part number for global deployment
- High efficiency (≥ 88%) — reduces operating costs and cabinet heating
- Ultra-low ripple (≤ 50 mV) — critical for powering analog I/O modules (e.g., X20AO4622) without measurement errors
- Comprehensive protection — prevents damage to expensive controllers and I/O modules
- Fanless design — zero noise, zero maintenance, IP20 rated
Applicable Industries:
- All industries using B&R Automation PC 910 controllers
- Machine building
- Panel building
- System integration
Installation Requirements:
- Mount on DIN rail TS35 near the Automation PC 910 controller for short power runs
- Use minimum 1.5 mm² wire for 24V DC output connections
- Do not daisy-chain multiple power supplies — each controller requires its own dedicated supply
- Ensure proper ventilation — minimum 20 mm clearance above and below the module
- Ground the AC input protective earth (PE) solidly
Usage Precautions:
- Do not exceed 5A (120W) total output current — overcurrent triggers protection and shuts down output
- Do not connect inductive loads directly to the 24V output without a flyback diode — voltage spikes damage the supply
- Verify output voltage (24V DC ±2%) with a multimeter before connecting the controller
- Do not operate above 70°C ambient — derating applies above 50°C (reduce current by 1% per °C)
- Replace immediately if the fault LED is illuminated — do not bypass protection circuits
