Lockout/tagout (LOTO) : Put shackles on the equipment before maintenance
Standard movements:
After cutting off the power supply, lock the switch with a special lock
2. Hang a warning sign that reads "Work in progress, do not close the switch" (the sign must be removed by the person themselves).
3. Check the voltage to confirm there is no voltage before taking action
Accident case:
An electrician in a certain factory failed to Lockout/tagout to repair the motor, and the operator mistakenly closed the switch, resulting in a fracture of the electrician's hand due to crushing. (After rectification, it is mandatory to have "one person, one lock, one plate".)
Ii. High-voltage Voltage Testing: Verifying Whether There Is Electricity or Not with One's Life
Standard movements:
1. First, test the electrical appliances on the powered equipment to ensure they are normal (make sure they are not broken!)
When testing for electricity, wear insulating gloves and hold the part below the protective ring
3. Two people must be present for high-voltage voltage testing (one person operates and the other supervises). Incorrect operation:
A novice tried to test for electricity with one hand but failed to notice the poor contact of the detector. He mistakenly judged that there was no electricity, resulting in electric arc burns. (Remember: Improper electricity testing has brought two lines of tears to your loved ones!)
Iii. Insulation Inspection: Give the circuit a "physical examination" to prevent leakage
Standard movements:
Measure the insulation resistance of the circuit with a 500V megohmmeter (if it is lower than 0.5MΩ, rectification must be carried out).
2. The motor winding is considered qualified only when the insulation between phases is greater than 2MΩ
3. In a humid environment, measure once a week; in a dry environment, measure once a month
Factory rectification:
The equipment in a certain workshop frequently tripped. After insulation testing, it was found that the cables were aged and damaged. After replacement, the tripping rate dropped to zero (saving 100,000 yuan in short-circuit repair costs!)