Which of the following sets the maximum time limit for restoration of power to other equipment during equipment fault or supply failure?

The correct answer is option 2) Distribution transformer fails/gets burnt

Explanation:

Fuse blown or MCB tripped: This situation can cause a power outage, but it involves a relatively quick fix, which usually involves replacing the fuse or resetting the MCB.

Distribution transformer fails/gets burnt: Normally, power restoration in this case takes the longest time among the given four options. A transformer failure is a severe incident; it can cut the power supply to many households or an entire area. Addressing such a situation involves identifying the issue, removing the failed transformer, procuring a new one, and installing it - a process that can take a substantial amount of time, and setting the maximum limit for restoration.

Service line break: Although this can disrupt power delivery, the repair period is generally less than the time taken to replace a transformer.

HT mains failure: While a high tension (HT) power line failure can affect a large number of consumers, recovery can be quicker than a transformer replacement if it only involves a line repair or the replacement of certain components.