Issues to be noted in the tuning work of Low-voltage distribution cabinet

2025-10-16 10:54:12

The setting work of Low-voltage distribution cabinet has a great impact on the operation of the system. Only by comprehensively carrying out the setting work can the good operation of the system be ensured. Therefore, during the work, it is necessary to constantly pay attention to parameter changes to ensure that the relay protection device can play its maximum function.

⑴ Operating standards

In order to avoid errors, when using short circuited flexible wires for overcurrent in DC large motors, it is necessary to strictly follow the operating procedures to ensure that the parallel distance between the flexible wire and the relay is controlled within the range of 1.5 to 2.0m and maintained uniformly. Violating the operating procedures and standards will cause the current magnetic field of the flexible wire to exert pressure on the current relay, while increasing the setting error and making the parameters less accurate.

⑵ On site operations

When performing overcurrent setting operation on DC large motors, it is greatly affected by the magnetic field of the space bus current. At this time, the magnetic field of the overcurrent relay will be abnormal, affecting the accuracy of the setting work. In order to ensure numerical accuracy, the overcurrent relay setting work should be carried out on site as much as possible during actual operation, so as to form data that is close to reality, avoid setting value errors, eliminate safety hazards during operation, and ensure the safety of the electrical system.

⑶ Reasonably handle high currents

When setting overcurrent or undercurrent relays, high and low currents are generally encountered. In order to ensure operational safety, it is necessary to directly read the low current meter to make the parameters more intuitive and avoid setting errors. For high current operations, it is necessary to use a shunt meter connection method to ensure safe and reliable operation.

⑷ Voltage doubling rectifier circuit operation

The Low voltage control box system adopts a double voltage rectification circuit design, which has insufficient load capacity. If there is a large load bypass, it will cause the voltage of the low-voltage motor setting circuit to not increase quickly. Only by doing a targeted double voltage rectification operation can stable operation be ensured. Regardless of whether it is overcurrent, overvoltage, or demagnetization relay setting or recalibration, it is necessary to operate under the premise of safety, disconnect the original system from the protective relay bypass, ensure accurate data, and achieve safe operation.