1. Wiring box installation surface holding force test: 
Device for applying a force of 40N to the center of the test object. 
Prevent torque application to the wiring box. 
The device used to apply force to the wiring box should not damage its functionality. Gradually apply a force of 40N in each direction parallel to the installation surface, for (10±1) seconds, with each direction at a 90° angle (according to IEC 60068-2-21), acting on each direction parallel to the installation surface for 30 minutes. 
No impact in the direction perpendicular to the installation surface, gradually apply a force of 40N for (10±1) seconds. The tension should be applied to the center of the box, acting on the direction perpendicular to the installation surface for 30 minutes without impact. 
2. Wire clamping test: 
Motor-controlled eccentric wheel rotation. 
Pull the PV cable without impact in 1 second, 50 times, applying a force of 30N in the axial direction. 
3. Wire thread retention torque test: Torque: 0.1N·m 
Rotation pointer: direct reading of torque value