What is a necessary condition before the use of a torque wrench in substation work?

The necessary condition before using a torque wrench in substation work is that it needs to be calibrated. Calibration ensures that the torque wrench is providing accurate measurements and applying the correct amount of torque to fasteners. This is crucial in substation applications where precise torque settings are vital for the reliability and safety of electrical connections.

Using a calibrated torque wrench helps prevent over-tightening or under-tightening, which could lead to equipment failure or safety hazards. Regular calibration checks ensure that any deviations in performance are corrected, thereby maintaining the integrity of the equipment being worked on.

In comparison, while factors like warming up the wrench, ensuring it is oiled, or checking for rust are important maintenance steps, they do not affect the accuracy of the tool as directly as calibration does. Therefore, calibration stands out as the essential condition for effective and safe torque application in substation work.