BDT – Bypass diode tester

Our bypass diode thermal tester is designed to assess the adequacy of the thermal design and long-term reliability of PV modules bypass diodes, which are used to limit the detrimental effects of module hot spot susceptibility.

Our bypass diode tester is our turnkey tester to determine the junction voltage (voltage drop) of bypass diodes that are built-in PV modules. The tester is fully automated and can trigger pulses of 1ms automatically once the bypass diodes have reached certain temperature levels. It fulfills all requirements of the bypass diode thermal test (MQT 18.1) specified in the IEC 61215 and IEC 61730. The report generator automatically analyses the recorded data and determines the maximum diode temperature that can occur in the field. It is possible to connect up to three diodes to the tester and all bypass diodes will be automatically tested.

Technical specifications

Simultaneous testing capacity 1
Pulse length 1 ms
Number of diodes which can be tested in parallel 3
Number of temperature levels for automatic trigger 5
Relevant standards and tests IEC 61215 ( MQT 18.1 Bypass diode thermal test); IEC 61730 (MST 25 Bypass diode thermal test)

Key facts

  • 100% automated testing
  • Can be operated in combination with any market-available climate chamber
  • Includes a test report generator
  • High-speed data acquisition for measuring current and voltage drop during the test
  • All sensors and data loggers included
  • We optionally offer a heating table if no climate chamber is available
  • ISO 17025 calibration certificates available

Software features

  • Intuitive graphical user interface for full remote control of the test stand
  • Predefined test schedules according to IEC 61215
  • Automatic shifting between pulse and constant current mode for 100% automation of the test
  • Manual mode for user-specific tests
  • Display and record of all relevant test parameters such as junction voltage, current, module temperature and diode temperature