High-voltage switch cabinet is very important in electrical power system equipment.Switchgear condition deterioration is one power causes a system failure. So, what are the common faults of high voltage switch cabinet?(A) outdoor-and indoorFrom the placement of high-voltage switch cabinet, can be divided into both outdoor and indoor, 10KV and below use the indoor type. Under … Continue reading Types of high voltage switchgear and analysis of common faults

A, the causes of short circuit(1) the connection error; (2) the insulation damage; (3) the operation error; (4) the mechanical damageB, the harm of short circuitBecause of the short circuit current without load, only flows in the power source internal resistance is very small, so the current large, strong currents will generate heat effect and … Continue reading How to prevent short circuit between electrical circuits

1, zero-sequence current protection of the protected area is how to divide?I survived the end of the line of zero-sequence current earthing short circuit through the protection the maximum setting of zero sequence currents; do not protect thefull length of the line, but should not be less than the length of the protected circuit15%~20%; zero-sequence … Continue reading Electrical knowledge

Mechanical reasons:① the motor fan is damaged or loose fastening screws of the blades, resulting in fan Ye Gai collide with the wind, its sound with the chink of light is small;II bearing wear or shaft is not straight, causing motor rotor eccentricity, which the stator and rotor are clean, the motor produces excessive vibration … Continue reading How to judge the fault causes from the abnormal vibration and sound of the asynchronous motor?

Result in asynchronous motor no-load current reasons are the following:① voltage too high: when the power supply voltage is too high, the motor produces magnetic saturation of the iron core, leading to excessive no-load current;② motor due to improper Assembly or after repair the gap is too large;③ number of stator winding is not enough … Continue reading What causes the no-load current of the asynchronous motor to be too big?

Causes of shaft voltage produced is as follows:① because of generator stator flux imbalance in the shaft of the generator EMF is on. Reason of unbalanced magnetic field is usually because local magnetic stator core is large (such as corrosion of the stator iron core), as well as between the stator and rotor air gap … Continue reading What is the reason for the generator shaft voltage? What harm does it have on the operation of the generator?

The so-called "jump" means when the breaker is, because the control switch is not reset or control switch contact device, automatic contact stuck, resulting in tripping control circuit is connected while still tripping, so the circuit breaker will repeatedly to "jump", we call this phenomenon as "jump". Jump protection is the use of the operating … Continue reading What is called anti jump blocking protection?

When the protective earthing of electrical equipment shell with a collision, the earth resistance than the midline of the resistance is large, after the ends of the earth and the formation of shell lining, are not enough to make the short circuit power supply automatic switch and insurance action, and grounding power, and the power … Continue reading In three-phase four wire system, why not allow a part of the equipment to connect to zero, and another part of the equipment used to protect the ground?