Here are a few clear and professional variations you can use, depending on the context:
Standard Safety Notice:
"Operation of rock drilling and wet shotcrete machines is strictly prohibited during power supply voltage instability."
Worksite Safety Warning Format:
WARNING
Do NOT operate rock drilling or wet shotcrete machines when the power supply voltage is unstable.
Risk of equipment damage and serious safety hazards.
Instruction Manual Style:
Note:
Ensure that the power supply voltage is stable before operating rock drilling or wet shotcrete machines. Operation under unstable voltage conditions is strictly forbidden.
Let me know if you want this translated, turned into a signboard design, or formatted for a safety manual.
