Customized Switchgear Cabinet Testing

 Customized switchgear cabinet testing is crucial for ensuring its safe and reliable operation. The following is a detailed introduction to

 its testing procedures and key points:

### Appearance and Structural Inspection

1. **Integrity of the Cabinet**: Check whether there is any deformation, damage, or scratches on the outer shell of the switchgear cabinet, 

and whether all components are tightly connected. For example, the welded parts should be firm without any false soldering or desoldering

 phenomena; the screwed connection parts need to be tightened without looseness.

2. **Verification of the Protection Level**: According to the customization requirements, check the protection level label of the switchgear cabinet.

 If the IP54 protection level is required, it is necessary to confirm that the cabinet is well sealed, and there are appropriate protective measures at 

the ventilation openings, operation holes, and other parts to prevent dust and water from entering. Use dust-proof testing equipment to simulate 

the dust environment for dust-proof testing; use a water spray device to simulate water splashing from different angles for waterproof testing.

3. **Operational Convenience**: Check whether the cabinet door opens and closes smoothly, and whether the opening angle meets the design 

requirements, which generally should not be less than 90 degrees to facilitate the operation and maintenance of the internal equipment. The positions 

of operation handles, buttons, and other components are reasonable, with clear markings, making them easy to identify and operate.

Youtube：https://youtube.com/shorts/Xuh7-6hZt1I

### Electrical Performance Testing

1. **Insulation Resistance Testing**: Use an insulation resistance tester to measure the insulation resistance between each live circuit in the switchgear 

cabinet and between the live circuit and the grounding circuit respectively. For switchgear cabinets with a rated voltage of less than 500V, the insulation

 resistance should not be lower than 2MΩ. For example, connect the test leads of the tester to the busbars of different phases and the grounding busbar

 respectively, read the insulation resistance value, and determine whether it meets the standard.

2. **Dielectric Strength Testing**: Use a withstand voltage tester to apply the specified test voltage to the switchgear cabinet for a certain period of time

 (usually 1 minute), and observe whether there are phenomena such as breakdown and flashover. The test voltage value is determined according to the

 rated voltage of the switchgear cabinet. For example, if the rated voltage is 380V, the test voltage is generally 2000V. During the testing process, if there

 are abnormal situations such as a sudden increase in current or a drop in voltage, it indicates that the dielectric strength does not meet the requirements.

3. **Ground Continuity Testing**: Use a grounding resistance tester to measure the grounding resistance between the grounding terminal and the outer 

shell of the switchgear cabinet and the metal frame of the internal equipment. The grounding resistance should not be greater than 0.1Ω to ensure that 

in case of faults such as electric leakage, the current can be reliably conducted to the ground, safeguarding the safety of personnel and equipment. 

Connect one end of the tester to the grounding terminal and the other end to the outer shell or the metal frame of the equipment, and read the grounding 

resistance value for judgment.

4. **Inspection of Electrical Clearance and Creepage Distance**: According to relevant standards and referring to the design drawings of the switchgear

 cabinet, measure the electrical clearance and creepage distance between conductive components of different potentials. For example, in the case of a 

rated voltage of 380V, the electrical clearance is generally not less than 6mm, and the creepage distance is not less than 10mm. Use tools such as calipers

 for accurate measurement to ensure that the requirements are met and prevent electrical breakdown and leakage.

### Function Testing

1. **Switch Operation Testing**: Perform multiple opening and closing operations on various switches in the switchgear cabinet, such as circuit breakers,

 disconnectors, contactors, etc., and check whether the actions are flexible and reliable, and whether the position indication is correct. Observe whether

 the contacts make good contact during closing and whether they are completely separated during opening. At the same time, check whether the actions

 of the auxiliary contacts are synchronized with those of the main contacts.

2. **Protection Function Testing**: Simulate fault situations such as overload, short circuit, and undervoltage to verify whether the protection functions of 

the switchgear cabinet are normal. For example, adjust the load current to make it exceed the overload protection setting value of the circuit breaker, and

 observe whether the circuit breaker can trip within the specified time; use a short-circuit generator to simulate a short-circuit fault and check whether the

 short-circuit protection device can quickly cut off the circuit; adjust the power supply voltage to make it lower than the undervoltage protection setting 

value and check whether the undervoltage protection function is activated.

3. **Signal Indication and Alarm Function Testing**: Check the signal indication devices such as indicator lights and displays in the switchgear cabinet to

 see whether the displays are accurate and clear under normal operation and fault conditions. For example, when the circuit breaker is closed, the closing

 indicator light should be on; when a fault occurs, the corresponding fault indicator light should be on, and at the same time, the alarm device (such as a 

buzzer) should emit an alarm signal.

### Temperature Rise Testing

1. **Loading and Operation**: According to the rated load of the switchgear cabinet, connect the simulated load to make the switchgear cabinet run 

continuously under full load conditions for a certain period of time (generally 2 - 4 hours). For example, for a switchgear cabinet with a rated current of

 100A, connect a resistive load of the corresponding power to make the current reach 100A.

2. **Temperature Measurement**: Use temperature measurement equipment such as an infrared thermometer or a thermocouple to regularly measure 

the temperature of each key part in the switchgear cabinet during the operation process, such as the switch contacts, busbar connection points, cable joints, etc. Record the temperature data before, during, and after the operation, and calculate the temperature rise. Generally, the temperature rise of the switch contacts should not exceed 65K, and the temperature rise of the busbar connection points should not exceed 50K. Excessive temperature rise may lead to equipment damage and affect the normal operation and service life of the switchgear cabinet.