Reference Project
Programmable DC Power Supply for Automated Circuit Breaker Testing
Industry Application: Electrical Protection & Industrial Test Automation
Sector: Electrical Protection
Application: Automated testing of circuit breakers
Status: Production
System configuration: Scalable test environment using 5–10 programmable DC power supplies per test system
Test volume: Tens to hundreds of thousands of household and industrial circuit breakers tested per year
Background: Reliable Power Supplies for Industrial Test Systems
In the industrial testing of circuit breakers, including miniature circuit breakers (MCBs), precise and repeatable electrical conditions are essential. Automated test systems require a highly accurate, stable, and programmable DC power supply to simulate real-world electrical loads, fault conditions, and trip characteristics.
The application is based on a scalable automated test environment for electrical protection devices. Depending on throughput and test configuration, multiple DC power supplies are operated in parallel, typically 5–10 units within a single testing environment. These applications have high demands for accuracy, reliability, and seamless integration into industrial automation systems.
Requirements
The DC power supply had to meet the following key requirements:
-
Precise and stable voltage and current regulation
-
Programmable DC power supply for automated test sequences
-
Fast response to load changes and switching events
-
EtherCAT communication for real-time industrial control
-
High reliability and long-term stability in 24/7 operation
-
Suitable for scalable test systems for household and industrial circuit breakers
Solution: SM 66-AR-110 Programmable DC Power Supply
The selected solution was the SM 66-AR-110 from the SM3300 series by Delta Elektronika.
This autoranging DC power supply delivers up to 3300 W output power and covers a wide operating range of 0–66 V and 0–110 A. This broad voltage and current window allows multiple circuit breaker test scenarios to be executed using a single power supply model, eliminating the need for manual reconfiguration or additional equipment.
Using an Anybus interface with EtherCAT support, the power supply was fully integrated into the industrial automation and control system.
Technical Benefits for Test & Measurement Applications
-
Autoranging technology for maximum flexibility across test scenarios
-
High voltage and current accuracy for repeatable test results
-
Excellent dynamic performance during switching and trip tests
-
Fully programmable voltage and current profiles
-
EtherCAT-enabled DC power supply for Industry 4.0 environments
-
Rugged design for industrial test and production systems
These features make the solution ideal for automated test equipment (ATE), end-of-line testing, and high-volume production testing of circuit breakers.
Results: Scalable and Reliable Test Infrastructure
By implementing the SM 66-AR-110, a highly reliable and scalable test infrastructure was realized in which multiple DC power supplies operate in parallel within a single test environment. The modular system architecture allows easy scaling to higher test volumes or additional test stations.
Precise regulation ensures consistent measurement results across large test volumes, while minimizing test time and reducing false failures. The modular interface concept ensures long-term future readiness, allowing straightforward adaptation to new test standards, communication protocols, or circuit breaker variants.
Customer Benefits at a Glance
-
High test accuracy for large production volumes
-
Scalable test systems using multiple DC power supplies
-
Optimized for automated industrial test environments
-
Reduced downtime and increased system availability
-
Seamless integration into EtherCAT automation architectures
-
Long-term reliable programmable DC power supply solution
