What action comes immediately after removing load in the grounding sequence for a unit substation?

• A. Open ACBs
• B. Ground line side of fuse
• C. Ground load side of fuse
• D. Open LBF

Answer: (A)

The action being tested is about truly isolating the substation from the source before touching it. After the load is removed, the next step is to open the main isolation device—the air circuit breakers. Opening these breakers interrupts the path from the incoming source to the transformer, making the unit de-energized and safe to work on. Grounding or touching line- or load-side conductors before this isolation could leave energized paths or create arcing risks, so the immediate priority is to disengage the circuit by opening the breakers. Once the circuit is opened and energy is removed, grounding can be applied in a controlled, safe manner to ensure any residual voltage is discharged.