Precautions for prefabricated substations mainly involve installation, operation, maintenance, and safety protection, and are crucial to ensuring long-term stable power supply and personnel safety.
Site Selection and Installation Precautions
Terrain and Drainage
The prefabricated substation should be installed in a high-lying area free from water accumulation to prevent rainwater from flowing back into the enclosure and affecting the insulation performance of electrical equipment.
Foundation and Levelness
The concrete foundation must be firm and level, with a horizontal error not exceeding 5mm, and provisions must be made for cable entry/exit channels and grounding electrode installation locations.
Ventilation and Heat Dissipation
The installation location should ensure good ventilation. The transformer room door should not be blocked to facilitate natural air circulation and heat dissipation. It is strictly forbidden to pile up debris around the enclosure, as this will affect maintenance and heat dissipation.
Reliable Grounding System
The grounding conductor should be a copper conductor with a cross-sectional area of not less than 30mm². The grounding grid should be buried at least 1 meter underground, and multiple vertical grounding electrodes should be installed to reduce grounding resistance, ensuring it does not exceed 4Ω.
Avoid Vibration and Electromagnetic Interference
It must not be installed in areas with strong vibration, impact, or strong electromagnetic induction to prevent damage to internal components.
Safety Management During Operation
Unauthorized Operation Prohibited
Unauthorized opening of the high-voltage room door is strictly prohibited. Insulated tools must be used during operation, mechanical interlocks must be properly disengaged, and live work is strictly forbidden.
Regular Load Checks
Conduct a routine inspection at least monthly, checking for three-phase load balance, overload, normal instrument readings, and correct switch positions.
Fire and Explosion Prevention Measures in Place
Flammable and explosive materials must not be stored around the enclosure. Qualified fire extinguishers (such as dry powder or carbon dioxide extinguishers) should be provided, and their pressure effectiveness should be checked regularly.
Prevent Small Animal Entry
All cable inlets and outlets must be tightly sealed to prevent small animals such as rats and snakes from entering and causing short circuits.
Maintenance and Care Points
Regular Dust Removal
Perform a thorough dust removal at least once a year. High-voltage and low-voltage rooms can be wiped with a damp cloth. For transformer rooms, it is recommended to use a blower or vacuum cleaner to remove dust.
Tighten Connections
Due to thermal expansion and contraction, terminals may loosen. All wiring terminals should be tightened annually after power is disconnected to prevent excessive contact resistance, which could lead to overheating or even fire.
Insulation Performance Testing
Perform an insulation resistance test annually. The insulation resistance of the 10kV system transformer windings should not be lower than 10MΩ. An AC withstand voltage test (e.g., 30kV/1min) can be performed if necessary.
Temperature and Humidity Control
Configure a temperature and humidity controller. The heating device should automatically activate when the ambient humidity is too high to prevent condensation. Fans should be repaired promptly if they malfunction.
Spare Circuit Handling
Unused high-voltage spare circuits should be closed before energizing, or the cable sockets should be sealed with dedicated insulating caps. Dust caps must not be used in place of insulating caps.