09,22,2026 15 views
A high and low voltage switchgear is a device that connects high or low voltage cables. The high voltage cabinet used in a substation is stepped down by a transformer to the low voltage cabinet, and then passed through the low voltage cabinet to various electrical distribution boxes. Inside, protective devices such as switches and circuit breakers are combined into an integrated electrical equipment.
When purchasing a switchgear, be sure to pay attention to the quality of the switchgear, otherwise it will affect normal use. The following are some points to note about the easy occurrence of faults in switchgear, which we should pay attention to:
1. Small air insulation gap: Due to some high-voltage switchgear manufacturers not strictly implementing the relevant technical standards of the switchgear, the air insulation gap between the phase and phase, as well as between the phase and ground of the charged bodies in some operating 10kV high-voltage switchgear cabinets is mostly between 100-125mm. As a pure air insulated electrical equipment, the "Technical Regulations for Design of High Voltage Distribution Equipment" clearly stipulate that the * * * small gap of pure air insulation in 10kV system is 125mm. Based on the results of AC withstand voltage test and accident analysis, it can be seen that the * * * small air insulation gap between phases and phases, and between phases and ground of the charged body in the 10kV high-voltage switchgear cabinet is less than 125mm, which is prone to accidents.
2. Poor insulation performance of supporting accessories: Some manufacturers use accessories with lower insulation levels in order to reduce costs, resulting in a decrease in the pollution flashover voltage of the entire switchgear, which cannot meet the rated standard requirements.
3. When using composite insulation, air gaps should not be ignored: Some 10kV high-voltage switchgear cabinets are equipped with insulation material partitions inside. From the actual situation, when using this composite insulation, air gaps should not be ignored. The air gap should not be less than 30mm, otherwise it is easy to cause insulation accidents.
4. Poor operating environment and low maintenance quality: Generally speaking, the operating environment of 10kV high-voltage switchgear is poor, often affected by factors such as dust, smoke, steam, etc., which corrode the surface of the insulation layer, generate conductive substances, and form insulation defects. There are also individual switchgear users who do not attach importance to equipment maintenance and repair, and cannot timely detect and eliminate various insulation defects, ultimately leading to insulation accidents.
