The five year car buffer test should be performed at which load and speed?

The five-year car buffer test is an important maintenance procedure that ensures the integrity and safety of the elevator's buffer system. The correct answer involves conducting the test at full load and full speed. This approach simulates the most extreme operating conditions the elevator could encounter in actual use, allowing for a comprehensive assessment of the buffer's performance under maximum stress.

By testing at full load, the system can demonstrate how well it absorbs the energy of a descending car when under maximum weight. Similarly, using full speed ensures that the buffers are evaluated on their ability to perform effectively in conditions that arise during normal operation. It’s crucial for determining whether the buffers can adequately absorb the kinetic energy of the moving elevator and prevent potential damage or catastrophic failure.

Other options suggest conducting the test under different combinations of load and speed, which do not reflect the worst-case scenario the buffers are designed to handle. Testing at these alternate settings might not provide sufficient insight into the buffer’s capacity, thereby missing critical evaluations that could compromise safety in actual service.