【Safety Article】Risks during maintenance operations

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Risks during maintenance operations Sequence Number Control Measures Accidents that may occur if control measures are not followed Severity Level of Violation 1 Understand the work location, tasks to be performed, and the surrounding environment, and identify and predict existing risks. In abnormal situations, the electrical switches cannot be controlled in a timely manner, resulting in casualties and equipment damage. Severe violation: Ask the equipment operator about the location of the fault and what happened before and after it occurred ； Check for any abnormal phenomena, such as smoking, noises, or a burnt smell. The situation is unclear, resulting in an injury accident. Severe violation: 3 Wear protective clothing properly, and fasten the cuffs and buttons of such clothing. Short-sleeved shirts, shorts, slippers, etc. are not allowed. It affects operational control, leading to loss of control and accidents. For general violations: Long hair exceeding the neck should be tied up inside a work hat. Hair getting wrapped around dangerous parts causes head injuries. For general violations, wear half-high impact-resistant shoes (or insulated shoes). The toe was injured by a blow, and the tendons were cut by metal shavings. Severe violation: The equipment’s grounding and neutral connection are firm and reliable, and the inspections have passed. Electric shock is a serious violation of safety rules; the power cable of the equipment must be connected to a qualified leakage protector. Electric shock is a serious violation of safety rules. 8 Persons other than the designated operators of this equipment are not allowed to assist in its maintenance. Misoperation can lead to personal injury or equipment accidents. Severe violation: Before maintenance, turn off the power, verify that there is no electricity, and hang a warning sign stating “Equipment under maintenance”. Inadequate preparation and oversights lead to personal injury. Severe violation: 10. Check whether there are any people, debris, or other factors inside and outside the equipment being repaired. The situation is unclear, resulting in personal injury. Severe violation: Sufficient lighting must be available when working at night. Electric shock, loss of balance or slipping can lead to bruises, bumps, or falls, or injury from getting trapped between machine tools or workpieces. Severe violation 12: It is strictly prohibited to place tools on equipment, to avoid the risk that they may be forgotten after repairs are completed, and fall into moving parts when the equipment is started up, or that they may drop or roll from a height and cause injury. Severe violation 13: During maintenance, it is necessary to ensure that the electrical equipment being repaired maintains good electrical insulation as well as proper connection to the ground. All protective barriers, electrical switch covers, doors, and other protective devices must be in good condition and functional. Person gets an electric shock. Severe violation: 14. Check whether the fuses have blown, whether the thermal relays have activated, whether any electrical components are burned out, overheating, or have broken wires; also check whether the wiring terminals are loose and whether the connection screws are tight. Person gets an electric shock. Severe violation: 15. Do not touch the metal parts of the test leads or the object being tested with your hands during measurement. Electric shock. Severe violations: 16. When permit-based procedures are required for equipment inspection, maintenance, and repair work, such permits must be obtained. Inadequate preventive measures led to casualties. For particularly serious violations: When performing maintenance and repair work, it is mandatory to cut off the power source and apply lockout/tagout measures. Safety signage must be posted, and a supervisor must be designated. Misoperation leads to casualties and equipment damage. Severe violation: 18. When analyzing the working principle of the control circuits of electrical equipment in situations with complex faults, power must not be supplied forcibly to locate the fault point until the fault has been identified. Improper work methods have led to injuries among personnel. Severe violation: 19. Working on live circuits is prohibited. It can cause equipment damage or casualties. Severe violation: Clear debris from the floor promptly. Puncture or cut the foot tendon. For general violations: 21. Clean up oil stains, debris, and flammable materials from the site promptly; store material carts in designated areas. Falls due to tripping or slipping, as well as fires and environmental pollution, fall under general violation category 22. The fumes generated from painting indoors contain harmful substances, so it is necessary to wear protective masks during such tasks. The fumes from lacquer cause poisoning symptoms. For general violations, protective earplugs should be worn in factory building 23 to deal with noise. Prolonged exposure leads to neurological disorders. General violations and other risk control matters A. Risk control when using a multimeter 1. Select the appropriate range and zero it. 2. Do not touch the metal parts of the test leads or the object being tested during measurement to avoid electric shock. 3. If the voltage range of the device being tested is unknown, start by selecting the maximum range, then gradually reduce it until the appropriate range is found. 4. Do not change the switch position during measurement to avoid sparks that could injure people. B. Risk control for using a megohmmeter 1. Do not measure the device under test while it is powered on. 2. The terminal being tested should be short-circuited and discharged before and after testing, to prevent damage to personnel and the megohmmeter caused by the discharge of electrical energy stored in the device’s capacitance. C. Risk control for the use of clip-on ammeters 1. Select an appropriate current rating. 2. When measuring current in bare wire busbars, one must stand on insulating pads and must not touch any other equipment to prevent short circuits or grounding. 3. When taking readings, make sure to maintain a safe distance between your head and the live parts. D. Risk control for the maintenance of electrical equipment under special circumstances 1. Maintenance while the equipment is powered on ① Protective gear must be worn, and operations should be carried out while standing on an insulating mat. ② Isolation panels should be installed on the accessible live parts. ③ One person must operate it, while another acts as a supervisor. 2. When working in flammable and explosive environments, it is necessary to pay attention to fire and explosion prevention. ① Turn off the power to the working environment. If lighting is needed, use a flashlight. ② Fire-fighting equipment such as fire extinguishers should be placed at the work site. 3. Climbing for maintenance① Qualified climbing tools must be used. ② During work, one person performs the task while another acts as a supervisor; the supervisor must not leave the scene without permission. E. Risk control for maintenance of electrical equipment under normal conditions 1. When maintaining equipment, it is necessary to follow the technical requirements specified in the drawings; generally, the principle of the electrical equipment should not be altered arbitrarily, and any technical modifications must be approved by the relevant authorities. 2. During maintenance, the equipment’s protection systems, such as overload, under-voltage, and lack of phase protection, should not be removed arbitrarily in an attempt to simplify the maintenance process. 3. Warning signs should be installed before the overall commissioning of the equipment; for large-scale equipment, a safety zone should be established to prevent unauthorized personnel from approaching. 4. When debugging the equipment, first conduct a thorough inspection of the debugging area to ensure that no one else is present. Then check for any hazards inside and outside the equipment that could interfere with the debugging process; debugging can only proceed once safety is ensured. 5. In the event of a fire involving electrical equipment, the power supply must be cut off immediately before attempting to extinguish the fire. Dry chemical extinguishers, carbon dioxide extinguishers, or carbon tetrachloride extinguishers should be used on live electrical equipment; foam extinguishers must not be used. 6. During the work process, it is necessary to foster a consciousness of clean production in order to minimize the generation of various pollutants. The workpieces should be cleaned before processing, as well as during and after the processing is completed. 7. All kinds of industrial waste generated during the production process must be properly handled and stored in separate categories; in particular, toxic and hazardous waste that poses a threat to the environment must be treated to meet specified standards before it can be discharged. Waste that cannot be processed is first collected for unified disposal. 8. After the work is completed, clean the equipment and the work area to ensure that all materials are used up and the area is tidy, thereby meeting the requirements of designated location management and HSE management. 9. Has the right to stop and correct others’ unsafe behaviors, and has the right to refuse orders to carry out work in violation of regulations