Voltage transformer disconnection fault handling method - Database & Sql Blog Articles

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

inductance

The voltage transformer is what we usually call PT, which is an electrical device that turns the high voltage of the circuit into a low voltage. Both the current transformer (CT) and the current transformer (CT) are used as the mains supply for measuring instruments, relay protection and automatic devices, and are essential for instrument measurement, relay protection and automatic devices. Its primary side is connected to the primary device, and the secondary side is connected to the secondary device. It is also the communication component between the primary system and the secondary system (only magnetic contact, and no electrical connection), which can reliably The secondary equipment is separated. Since the operation of the voltage transformer affects both the primary device and the secondary system, the voltage transformer must have high reliability. In theory, the voltage transformer generally does not have an accident, especially like an iron chip. Malignant accidents such as insulation damage, winding breakage, and winding-to-ground insulation breakdown. Our company has been building the factory for 20 years. I have checked the previous data and found no cases of major faults in the voltage transformer. The common problem is that the voltage transformer circuit is broken. We have encountered this kind of failure twice during the duty period. According to our own work experience and consulting the relevant materials, we will sort out the PT loop disconnection processing method as follows: When the running PT loop is broken, the following phenomenon is displayed: “Voltage The circuit is broken. The light plate is bright and the alarm is ringing; the voltmeter indicates zero or the three-phase voltage is inconsistent, the active power meter indicates the abnormality, the energy meter stops; there may be a ground signal (when the high-voltage fuse is blown); The monitoring voltmeter is lower than the normal value, and the phase voltmeter indicates normal. The possible causes of disconnection of the PT circuit are: high and low voltage fuses are blown or poorly contacted; the secondary circuit of the voltage transformer is in poor contact; the auxiliary switch contacts of the PT high voltage side isolating switch are connected in series on the secondary side, and the isolating switch The relay contact of the auxiliary contact linkage is also connected in series on the secondary side, and the secondary circuit is disconnected due to poor contact of the contacts; the secondary side fuse is blown by the secondary side due to the short circuit; the secondary circuit The connector is loose or broken. If a loop break occurs, it can be handled as follows: 1. Deactivate the relay protection and automatic device to prevent misoperation; 2. If the instrument is incorrectly indicated due to secondary circuit failure, it can be based on other instruments. Instruct, monitor the operation of the equipment, and do not change the operation mode of the equipment to avoid misoperation. 3. Check if the high and low voltage fuses are blown. If the high-voltage fuse is blown, the cause should be replaced and the low-voltage fuse should be replaced immediately if it is blown. 4. Check whether the contact of the secondary voltage circuit is loose or disconnected, and the switching circuit has poor contact. The above content is the practical experience we have accumulated over the years. We are now providing you with joint research and discussion to find a safer, more effective and more reliable prevention and treatment method.