Electrical switch cabinets need to be tested before leaving the factory and putting into use to ensure the safety of use. The test content is mainly divided into routine test and performance test:
1, general test
(1) type test: a test conducted on one or more devices or equipment manufactured according to a certain design requirement to check whether this design requirement meets a certain specification.
(2) Routine test: also known as ex-factory test, a test conducted on each device or equipment during or after manufacturing to determine whether the device or equipment meets a certain standard.
(3) Dielectric test: refers to various tests to test the electrical characteristics of dielectrics, including insulation, static electricity, withstand voltage, etc.
(4) Sampling inspection: a number of samples are randomly selected from a batch of products for inspection, which is also used to determine whether the samples meet a certain standard.
(5) Life test: a test to determine the possible life of a product under specified conditions, or a test to evaluate and analyze the life characteristics of a product is a destructive test.
(6) Durability test: The test of products under specified conditions, including specific operations for a certain purpose within a certain period of time, such as repeated operation, short circuit, overvoltage, vibration and impact, is a destructive test.
(7) Debugging test: the test conducted on site to prove the correct installation and normal operation of the product.
2. Characteristic test
(1) insulation test: series resonance test device and high voltage withstand device are used to test the insulation performance of the switchgear.
(2) Main circuit resistance measurement and temperature rise test: The temperature rise performance, such as switch contact resistance, solder joint resistance, copper plate resistance, etc., is detected by the circuit resistance tester.
(3) Peak withstand current and short-time withstand current test: use recommended high-voltage test transformer and oil-immersed high-voltage test transformer for test.
(4) On-off and on-off capability test Mechanical test: test with switch characteristic tester.
(5) Protection level test: It is recommended to use a large current generator, also called a current riser, to test whether the overcurrent protection function of the switch and the protection characteristics of the circuit breaker are qualified;
(6) Power-on test: Use the power-on test bench for high and low voltage switchgear (also called multifunctional debugging test bench) to conduct various power-on tests for high and low voltage switchgear before leaving the factory.
Second, what are the precautions for switchgear test?
When testing switchgear, we must pay attention to the safety of the test, especially the high-voltage switchgear. During the test, attention should be paid to:
1. Before the test, the tester shall be trained to ensure the safety, reliability and accuracy of the test, and the test shall be conducted in strict accordance with the relevant preventive test operation procedures for electrical equipment.
2. When testing under the condition of incomplete power failure on site, measures should be taken to prevent induced electric injury, such as wearing insulating gloves, shoes, and hanging temporary grounding wires on power failure equipment.
3. When testing, pay attention to observe the test instrument to see if there is a big fluctuation in the instrument, and also listen to the sound of the equipment under test. If there is obvious abnormality, the pressure gauge does not trip, which does not mean that it must be qualified. There may be foreign objects in the switch cabinet, which need to be checked according to the actual needs.
4, test, attention should be paid to control the error, such as temperature rise test, to control the surrounding airflow speed, to avoid the influence of adjacent high voltage switchgear heating, etc.
5, test equipment shell should be well grounded. The grounding wire shall be made of bare copper wire with sufficient electrical strength and mechanical strength. Do not disconnect the ground wire before removing the power wire.
6, switch cabinet test should adopt the system of mutual inspection, that is, two people do the test, after wiring by one person, the other person checks and confirms.