How many testing devices should be used when testing each conductor of a deenergized cable?

When testing each conductor of a deenergized cable, using two testing devices is standard practice. This method provides a means of verification, ensuring that the readings can be corroborated. One device can serve as a primary testing instrument, while the second acts as a backup or means for double-checking the results. This redundancy is crucial in electrical work, as it helps to minimize the risk of error or misinterpretation of the test results.

Utilizing two devices increases the reliability of the test outcome and enhances safety measures during the testing process. It is essential, especially in high-stakes environments like those faced by linemen, to confirm that the cable is indeed deenergized before proceeding with any work. Having dual verification through two devices ensures a higher level of confidence in the safety and integrity of electrical systems during maintenance or repair tasks.