Operation, maintenance and management of residual current transformers

- Nov 04, 2020-

(1) After the residual current transformer is put into operation, the user should establish operation records and corresponding management systems

(2) Electricity management personnel should conduct power-on trip test for the residual current transformer at least every month, that is, press the test button to check whether the residual current transformer is reliable. Whenever a lightning strike or other reasons cause the residual current transformer to operate, it should be checked and a trip test should be carried out. In the peak season of rural power consumption, the number of trip tests should be increased; the out-of-service residual current transformer should be tripped and tested once before use.

(3) In order to fully grasp the operating status of the residual current transformer, the residual current transformer should be sampled and tested regularly (such as during the annual safety inspection).

(4) The testing of residual current transformers should be organized by the full-time safety management personnel of the power supply station under the guidance of the local power department. The items for regularly testing the operating characteristics of the residual current transformer should include the residual operating current value, the remaining non-operating value, and the breaking time.

(5) The test content of the low-voltage power grid includes the unbalanced leakage current to the ground of the protected power grid, the protected power grid and various loads, the insulation resistance value of the motor, the neutral point leakage current of the low-voltage side of the distribution transformer, and various electricity consumption The grounding resistance of the equipment protective grounding device. The test data is compared with the last test result for comprehensive analysis. Those who fail the test or have major defects should be repaired or replaced in time.

(6) The operation characteristic test of the residual current transformer and the simulated leakage operation test of the protection grid shall use special measuring instruments qualified by the relevant state departments and be operated by professionals. It is strictly forbidden to use the phase line to directly touch the grounding device to conduct the simulated leakage action test of the protection grid.

(7) The trial jump, test, setting and test process must be recorded by a special person, and the recorded items and data must not be confused or wrong, for future reference during operation analysis.

(8) If an electric shock accident occurs within the protection range of the residual current transformer, the operation of the protector should be checked, the cause should be analyzed, and the accident report should be written. Note: Before the power department sends someone to inspect, the site must be protected and the protector site must not be modified.

(9) If the user intentionally causes the protector to refuse or misoperation, he shall be given criticism and education and warning. Those who still do not repent after the criticism and education can temporarily stop the household's electricity consumption.

(10) After the residual current transformer is operated, if the cause of the accident is not found after inspection, it is allowed to test power once. If it is operated again, the cause should be found out to find out the fault, and no continuous forced power transmission is allowed. Unless it is confirmed that the residual current transformer itself is faulty after inspection, it is strictly forbidden to remove the residual current transformer without authorization and force the power supply.

(11) The maintenance of the residual current transformer should be carried out by professionals. If there is any abnormal phenomenon during operation, an electrician should be found to avoid expanding the scope of the accident.

(12) The power supply station should be equipped with commonly used test meters and a certain number of backup protectors. The operation of the residual current transformer should be analyzed regularly, and the residual current transformer that cannot be used normally should be replaced in time.https://www.ctsensorducer.com/