6~20kV Substation low voltage commonly used main wiring（One transformer and diesel generator set）

Power Off and Power On Sequence in the Distribution RoomPower-off sequence:When de-energizing, first disconnect the low-voltage (LV) side, then the high-voltage (HV) side. When de-energizing the LV side:First open all LV branch circuit breakers, then open the LV main breaker. Additionally, disconnect the control circuits before de-energizing the main power circuits. When de-energizing the HV side:First open the circuit breaker, then open the isolating switch (disconnector).If the HV incoming lin

Very often, the lowest-level circuit breaker does not trip, but the upstream (higher-level) one does! This causes a large-scale power outage! Why does this happen? Today, we’ll discuss this issue.Main Causes of Cascading (Unintended Upstream) Tripping The main circuit breaker’s load capacity is smaller than the total load capacity of all downstream branch breakers. The main breaker is equipped with a residual current device (RCD), while the branch breakers are not. When appliance leakage current

Substations designed for voltage levels ranging from 55 kV to 765 kV are known as outdoor substations. This type of substation requires less construction time but occupies more space. Outdoor substations are mainly divided into pole-mounted substations and foundation-mounted substations.Pole-Mounted SubstationsThis type of substation is used to support distribution transformers with capacities up to 250 kVA. Such transformers represent the cheapest, simplest, and smallest form of distribution. A

Essential Rules for Three-Level Power Distribution System Design1.Hierarchical and Branch Circuit Distribution(1) Power distribution from the primary main distribution board (distribution cabinet) to secondary distribution boards can be branched; that is, one main distribution board may supply power via multiple branch circuits to several secondary distribution boards.(2) Similarly, power distribution from a secondary distribution board to tertiary switch boxes can also be branched; that is, one