What tests need to be carried out after the assembly line of electric cabinet is debugged?

Electrical performance test

Insulation resistance test

Objective: To check the insulation performance of the electrical circuits and components in the electrical cabinet, to ensure that there will be no leakage phenomenon under normal working voltage, and to ensure the safety of operators and the normal operation of equipment.

Methods: Using insulation resistance meter (megger) to test different lines and components in the electrical cabinet. When testing, connect the two test wires of the insulation resistance meter to the two ends of the tested line or component, for example, to different positions such as phase-to-phase and relative ground. For electrical cabinets with rated voltage below 1000V, the insulation resistance should generally be not less than 1 mω; For electrical cabinets with rated voltage of 1000V and above, the insulation resistance is usually required to be no less than 1MΩ/kV.

Withstand voltage test

Objective: To verify that the electrical insulation system of the electrical cabinet can withstand the specified voltage without breakdown or flashover, which is an important test to ensure the safety and reliability of the electrical cabinet under overvoltage.

Methods: withstand voltage tester was used for the test. Connect the high-voltage output end of the tester to the conductor part of the tested electrical cabinet, such as the phase line, and the grounding end is connected to the grounding part of the electrical cabinet. Gradually increase the test voltage to the specified value, generally 1.5-2 times the rated voltage, and keep it for a period of time (usually 1-5 minutes). During the test, observe whether there is breakdown discharge phenomenon, if not, it means that the withstand voltage performance is qualified. For example, for an electrical cabinet with a rated voltage of 380V, the test voltage can be increased to 760-1000V V..

Grounding resistance test

Objective: To ensure that the grounding system of the electric cabinet is good, and the current can be quickly introduced into the earth in case of fault, so as to prevent electric shock accidents.

Methods: The grounding resistance tester was used to test. Insert the current electrode and voltage electrode of the tester into the ground according to the specified distance (generally, the current electrode is 40m away from the grounding electrode and the voltage electrode is 20m away from the grounding electrode), and then connect the test wire of the tester to the grounding terminal of the electric cabinet. The grounding resistance value obtained by testing should not be greater than 4Ω in general, and it may be more stringent in some special requirements, such as not greater than 1Ω.

Loop resistance test

Objective: To measure the resistance of main electrical circuits (such as bus connection, circuit breaker circuit, etc.) in the electrical cabinet, so as to evaluate the conductivity of the circuits and ensure that excessive voltage drop will not occur under normal working current.

Methods: Micro-ohmmeter or special loop resistance tester was used to test. For the large current loop, the specified test current (such as 100A-1000A) should be applied during the test, the voltage drop at both ends of the loop should be measured, and the loop resistance should be calculated according to Ohm's law. For example, the loop resistance of the bus connection point should meet the value specified in the product standard, and it is generally required to be within the range of micro-European level.

functional test

Control function test

Objective: To verify that the control system (such as PLC, relay logic control, etc.) of the electric cabinet assembly line can correctly control all actions of the equipment, including the start and stop of the motor, the operation of the conveyor belt, the clamping and loosening of the fixture, etc., so as to ensure that the assembly process is carried out in a predetermined order.

Methods: The response of the equipment was observed by manually operating the buttons and switches on the control panel or sending control instructions through the upper computer software (if any). For example, after pressing the motor start button, check whether the motor runs according to the set speed and direction; Operate the control instructions of the assembly robot to see if the robot's actions are accurate. At the same time, check the interlocking control function between devices, such as whether the related devices can stop running correctly when one device fails.

Protection function test

Objective: To check whether all kinds of protective devices (such as overload protection, short circuit protection, under-voltage protection, etc.) of the electric cabinet assembly line can work normally, and to protect the safety of equipment and personnel in time in case of abnormal situation.

Methods: Simulate all kinds of faults to test. For example, if the motor is overloaded by increasing the load, check whether the overload protection device (such as thermal relay) can act in time to cut off the motor circuit; For short-circuit protection, some lines can be short-circuited under safe conditions (such as through a special short-circuit test device), and whether the fuse or circuit breaker can quickly cut off the circuit can be observed. When testing undervoltage protection, adjust the power supply voltage to a set value lower than the rated voltage to see if the protection device can work normally.

Communication function test (if any)

Objective: For the electrical cabinet assembly line with communication function (such as data communication with the upper computer monitoring system and other equipment), it is necessary to ensure the stability and accuracy of communication and realize the correct transmission and interaction of data.

Methods: Communication testing tools (such as serial debugging assistant, network tester, etc.) were used for testing. Check whether the connection of communication lines is correct, and verify the implementation of communication protocols by sending and receiving test data. For example, for the electrical cabinet assembly line with industrial Ethernet communication, check whether the IP address setting is correct and whether the functions of real-time data acquisition and remote control can be realized.

Mechanical performance test

Conveying system test

Objective: To evaluate the operational performance of conveying system (such as conveyor belt, roller conveyor, etc.), including operating speed, stability, bearing capacity, etc., so as to ensure that it can meet the material conveying requirements in the assembly process of electrical cabinets.

Methods: Use a speedometer to measure the running speed of the conveyor belt and check whether it meets the design requirements. The speed error should generally be controlled within 5%. Observe the stability of the conveying system during operation, and check whether there is vibration, deviation and other phenomena. By gradually increasing the conveying load (such as placing electrical cabinets with different weights), the carrying capacity of the conveying system is tested to ensure that it can operate normally under the rated load and will not have serious faults when it is overloaded by a certain proportion (such as 10%-20%).

Operating platform and fixture testing

Objective: To check whether the lifting and translation functions of the operating platform are normal, and whether the positioning accuracy and clamping force of the fixture meet the requirements of electrical cabinet assembly, so as to ensure the smooth assembly.

Methods: For the operating platform, the lifting and translation operations were repeated to check the stability and accuracy of its movement, and the positioning accuracy of the platform was measured with measuring tools, and the error should generally be controlled within 1 mm. For the fixture, use the pressure sensor to measure the clamping force of the fixture to ensure that the clamping force is within the specified range, and the electric cabinet or electrical components can be firmly fixed. At the same time, check the positioning accuracy of the fixture, and observe whether the fixture can accurately guide the installation position of electrical components through actual assembly operation. The positioning accuracy error is generally required to be less than 0.5 mm.