The differences are reflected in four dimensions: work attribute, energy isolation condition, operation procedure and risk control, as detailed below:
1. Work attribute: Normal LOTO is routine, planned and regular daily maintenance work; Abnormal LOTO is unplanned, emergency, temporary or complex non-routine work.
2. Energy isolation condition: Normal LOTO involves a single, independent, lockable energy source with simple and clear isolation points; Abnormal LOTO involves multiple coupled energy sources, non-lockable isolation devices or hidden residual energy risks.
3. Operation specification: Normal LOTO follows fixed SOPs, with independent operation by authorized employees and conventional process verification; Abnormal LOTO requires special safety approval, cross-post coordination, enhanced zero-energy verification and on-site supervision, and allows tagout-only operation only when lockout is physically impossible (with official documentation required).
4. Risk level: Normal LOTO has controllable, predictable low risks with standardized risk prevention measures; Abnormal LOTO has uncertain, complex high risks, prone to residual energy release and accidental equipment startup hazards.