Temperature-Rise test of Large Capacity Generator Circuit Breaker

The temperature rise test is a crucial test for generator circuit breakers to verify their current - carrying capacity. In this test, the maximum test current can reach as high as 35 kA to simulate the real operating environment. The test sample is a complete three - phase installation, but the test is only conducted on a single phase. The air temperature can be adjusted using cooling water.
The implementation of this test mainly focuses on the following three aspects, and the layout of the experimental site is shown in the figure. The following points should be noted during this test:

1.Attention to the Test Loop and Sample Resistance under High - Current Testing
Under high - current test conditions, it is essential to pay close attention to the test loop and the resistance of the sample. To avoid excessive voltage drops, it is necessary to reduce the current - carrying capacity of the connecting cables, select test equipment with appropriate capacities, and enhance the port voltage output capacity.

2. Appropriate Layout of the Test Loop
Using an appropriate test loop layout can effectively reduce the total power - frequency electrical impedance during operation. It can also prevent issues such as the skin effect, hysteresis losses, and heat generation in the test circuit body caused by multi - wire connections, which could otherwise affect the normal progress of the temperature rise test.

3. Temperature Adjustment under Forced Air - Cooling Test Conditions
Under forced air - cooling test conditions, since the adjustment of the wind temperature is achieved through heat exchange with the water temperature, there is a time lag. Therefore, adjustments should be made based on the temperature limits. It is necessary to make slow adjustments within the allowable temperature range to ensure accurate control of the test environment.