THERMAL CYCLING (TC 200) TESTING FOR SOLAR MODULES

TC 200 refers to Thermal Cycling test. Thermal cycling is the test or process of cycling a material or device through two set temperature extremes, usually at a somewhat high rate of change of temperature. It is defined as an environmental stress test used to evaluate the reliability of the material or the product and to identify any manufacturing defects early by inducing failure modes through the thermal fatigue. It is one of the main qualifying tests carried out on PV modules .

Test procedure

For TC 200 testing, a current within +/-2 percent of the current measured at the peak power when the temperature of the solar module is above 25 Cal should be injected. The tested solar module is subjected to the cycling temperature limits of an extreme low temperature of - 40 cal +- 2 cal and an extreme high temp of + 85 cal +- 2 cal .
Many factors can affect the TC 200 test, that's why special consideration shall be given to the number of cycles (200), temperature ranges, dwell times and rates of temperature change.

Problem Detection

Aging of PV modules is the deterioration of performance of PV modules over time. Accelerated aging tests can be used to test the durability and safety of manufactured PV modules. Thermal cycling (TC 200) tests are done for PV module certification and defined in IEC 61215 (200 cycles, temperature limits of - 40 Cal and + 85 Cal ) and those conditions correspond to an estimated 10 years of field installation and operation in average climate conditions. TC 200 can also detect cracks and low shunt defects for solar modules over extended periods of operation.

What are IEC 61215 conditions for Thermal Cycling (TC 200) test of PV modules?

61215 conditions for TC 200 testing are a temperature range of - 40 Cal to + 85 Cal , a cycle period of nearly 6 h and For T > 25 cal, and electrical current flow of 8 Amps (Current flow injected only on working hours due to safety reasons - equals roughly 1/3 of regular test time).