Discharging voltage is to prevent residual charge in capacitors from injuring personnel. Safe methods for discharging voltage include: When opening cabinet doors or panels, never touch the busbar directly with your hands. First, use a 10kV test pen to check for voltage.
Then, find a wire, ground one end, and connect the other end to the tip of the test pen. Use the tip of the test pen to discharge the voltage by touching the busbar. Only after this is complete can maintenance be performed, ensuring personal safety.
There are several methods to reduce the voltage to a safe level, including using a step-down transformer, reverse voltage regulation, forward voltage regulation, and constant voltage regulation.
Using a step-down transformer
The overvoltage protection value can be adjusted to around 425V, or a step-down transformer (outputting 410V when the voltage is 420V) can be used to supply the overvoltage protector as the monitoring voltage.
Reverse Voltage Regulation Method
Considering the increased voltage loss on power lines during peak grid load, the central point voltage should be increased to compensate for or even offset the increased voltage loss. Conversely, during off-peak load periods, the corresponding voltage loss on the lines is smaller, so the central point voltage is decreased to compensate for the reduced voltage loss. This voltage regulation method is suitable for central points with long power lines and large load fluctuations. When using reverse voltage regulation, the central point voltage can be increased to 5% higher than the rated value during peak load and reduced to the rated value during off-peak load periods.
Forward voltage regulation
Means that the central point voltage is allowed to be slightly lower during peak load and slightly higher during off-peak load. In contrast to reverse voltage regulation, forward voltage regulation can be used for central points with short power supply lines and small load fluctuations. Generally, with forward voltage regulation, the central point voltage can be at least 2.5% higher than the rated voltage during peak load and at most 7.5% higher during off-peak load.
Constant Voltage Adjustment Method
A middle ground between reverse and forward voltage adjustment can be used, where the voltage at the middle point remains essentially constant under any load, for example, 102% to 105% of the rated voltage.
All of the above methods can effectively reduce the voltage to a safe level; the specific method used depends on the actual situation.
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Our VTZ-12 vacuum circuit breaker is suitable to control and protect transmission and distribution system such as electric network equipment and industrial & mining industry etc as their protection and control unit.
Shaanxi West Power Tongzhong Electrical Co., Ltd.
Our address
Nanpo Village, Chencang Avenue Jintai District Baoji City, Shaanxi Province, China.
Phone Number
+86 18091767067(WhatsApp/Wechat/Telegram)
