\"Sharing Winter Anti-freezing Experience: Project Electrical and Instrumentation Construction\"

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\"Sharing Winter Anti-freezing Experience: Electrical Installation Projects\" – Electrical Engineering Field: 1. On-site materials, especially distribution panels, cabinets, control boxes, and operation consoles, should be placed indoors whenever possible. If the materials are too large or numerous to be moved indoors, they should be covered with waterproof canvas to prevent them from getting damp due to rain or snow. 2. During construction in the electrical distribution room during winter, it is strictly prohibited to use heat-generating light sources as heating equipment, such as iodine-tungsten lamps. If heating equipment is indeed necessary, qualified electric heaters can be used; they should be turned on during working hours and turned off after work. Fire extinguishers must also be available, and regular checks should be carried out to prevent fires caused by malfunctions. 3. Precautions for cable laying work in winter: According to the \"Code for Construction and Acceptance of Industrial Automation Instrumentation Projects (Standard)\” GB/50093-2002 (GBJ93-86), the ambient temperature should not be lower than the following values: 1. For cross-linked polyethylene cables, it is 0°C. II. Low-voltage plastic wires – 20°C. III. Rubber and PVC sheaths; rubber-insulated cables – 15°C. If the above conditions are not met, the contractor will move the cables as a whole to a building with sufficient space (where the indoor temperature is maintained at around 25°C) for preheating. Once the cable temperature reaches and exceeds the specified level, the cables will be laid quickly; the laying time should not be too long, and it should be kept within 4 hours (the ideal time is between 10 am and 2 pm). 4. Cable terminal fabrication must not be carried out in humid weather conditions, especially for high-voltage cable terminals ； When manufacturing cable terminals at -5°C, moisture protection measures are necessary, such as using electric heaters ； The work of manufacturing high-voltage cable terminations should be carried out continuously, without any interruptions of more than 1 hour, to prevent the cable terminations from becoming damp due to condensation. 5. When disassembling and inspecting electric motors in winter, it is necessary to ensure fair weather with an outdoor temperature of above 5°C. During the disassembly and inspection process, it is important to prevent moisture from entering the motor’s interior, as this could reduce the motor’s insulation properties ； Before testing the motor, measure its insulation, and turn on the internal heater of the motor 2 hours in advance to ensure that it has a high insulation resistance value. 6. In case of strong winds, rain, or snow, cease all outdoor electrical work to prevent the equipment from getting wet ； When working on utility tunnels, the snow or ice accumulation must be removed first; moreover, workers performing tasks at heights must wear anti-slip shoes to prevent injuries. 7. New switchgear requires power-on commissioning. Before powering it on, check whether there is any dew inside the switchgear; if dew is present, turn on the heater located on the switchgear first to dry it out before proceeding with the power-on commissioning. When a new transformer is brought online or an existing transformer is taken out of service, check the oil level of the transformer as well as for any signs of oil leakage around it immediately after the transformation is carried out. Unless there is a specific need, try to avoid turning the transformer on or off, in order to prevent seal failures due to temperature changes that could lead to oil leakage. For the instrumentation field: 1. When manufacturing cable terminals at -5°C, moisture protection measures must be taken. 2. For all instrument equipment and pipelines that are to undergo pressure testing in winter, it is necessary to pay close attention to the weather conditions on that day before carrying out the pressure testing or trial operation, and conduct it at midday when the temperature is higher. 3. For the pressure testing of the instrument pipeline system, a high-point vent should be installed at the highest point of the system to ensure that all air within the system is removed during water filling. 4. For the pressure testing of equipment pipelines, water should be introduced on the same day as the testing is carried out; once the testing is complete, the water must be drained completely and the area dried using compressed air. 5. After pressure testing or calibration, the instrument equipment should be checked for any water (oil) remaining inside, and such water (oil) must be drained completely. 6. Instrumentation installed outdoors must have measures in place to protect it from rain, snow, and freezing, and it should be under the supervision of a dedicated person; regular moisture release is necessary to prevent rusting due to moisture absorption. 7. During welding of instrument pipelines in winter, measures should be taken to protect them from wind, snow, and rain. The ends of the pipes to be welded must be sealed to prevent drafts from passing through. When the ambient temperature is below 0°C, the area around 200 mm from the starting point of welding must be preheated to a temperature above 15°C before welding can proceed