What should be done if the isolation device cannot be visually confirmed as open?

• A. Remove the fuses
• B. Visually confirm it is open
• C. Lock out the control circuit
• D. Ignore and proceed

Answer: (A)

When you cannot visually confirm that an isolation device is open, the safest course is to physically remove the energy source so the circuit can no longer be energized. Removing the fuses directly breaks the power path, guaranteeing there is no current anywhere in the circuit, even if a switch is stuck, misindicating, or there’s a fault in the indication. This concrete interruption of energy is essential for safe work.

After removing the fuses, you would typically lock out the control circuit to prevent any accidental re-energization and tag the device to communicate its status to others. This combination ensures the circuit stays de-energized while work is performed.

Ignoring the energy source, or proceeding based on an uncertain indicator, is unsafe because it leaves the possibility of unexpected energization. Visual confirmation alone isn’t reliable when it cannot be verified. Removing the fuses provides a definite, verifiable de-energized state.