What is the standard for Buchholz relay?

Answered by Stephen Mosley

The standard for Buchholz relay is designed with several key aspects in mind to ensure its effectiveness and reliability. This device plays a crucial role in protecting oil-filled transformers and other electrical equipment from faults and abnormal conditions.

1. Pressure Resistance: The cast body of the Buchholz relay is constructed to withstand a specific pressure. The standard requirement is that it should be able to endure a pressure of 8kg/cm2 for a duration of 1 minute without any damage or leakage. This ensures that the relay can handle the internal pressure generated during abnormal conditions without any failure.

2. Leak Test: After the relay is fully assembled, it undergoes a leak test. This test checks the integrity of the relay by subjecting it to a pressure of 1.5kg/cm2. If the relay shows any signs of leakage during this test, it fails to meet the standard requirements and is considered faulty. The absence of any leakage ensures that the relay can effectively contain the oil within the system, preventing any potential hazards.

3. High Voltage Test: The Buchholz relay is also subjected to a high voltage test. This test is conducted to verify the insulation properties of the relay and its ability to withstand high voltage conditions. The relay is exposed to a high voltage for a specific duration, and it should be able to withstand this without any breakdown or damage. This ensures that the relay can effectively detect and respond to faults in the transformer insulation.

4. Insulation Resistance Test: Another important test conducted on the Buchholz relay is the insulation resistance test. This test measures the resistance between different electrical components of the relay to ensure that there are no short circuits or leakage paths. The relay should exhibit a high insulation resistance value, indicating that it can effectively isolate electrical signals and maintain proper functionality.

The standard for the Buchholz relay encompasses pressure resistance, leak testing, high voltage testing, and insulation resistance testing. These tests ensure that the relay can withstand abnormal conditions, detect faults accurately, and provide reliable protection for oil-filled transformers. Adhering to these standards is essential for maintaining the safety and efficiency of electrical systems.