Installed between the main transformer tank and the conservator, Buchholz relay has the ability to monitor gas formation and oil movement in case of internal defects. Dhruti Sales is happy to offer various configurations of Buchholz relay such as GOR-1, GOR-2, and GOR-3 designed to be used in transformer protection.
What Is Buchholz Relay?
It is the case that Buchholz Relay is the protection apparatus working in terms of gas and applied mostly in oil-filled transformers and reactors. This device plays a vital role in detecting inner defects in oil transformers before they lead to serious issues.
Transformer oil can break down and form gases when there’s an internal issue. Depending on how serious the fault is, the relay may trigger an alarm or send a trip signal to cut off the transformer from the system.
Most relays are installed in the pipe leading from the main transformer tank to the transformer conservator, which allows them to detect both gas formation and sudden movements of oil in the device.
Working Principle of the Buchholz Relay
The basic Buchholz relay working principle is to identify two important events: gas formation caused by minor faults or the oil flow caused by more severe issues.
Detection of Minor Faults
Minor faults such as insulation damage, localized overheating, or other internal problems can lead to the formation of gases in the transformer oil.
The gases rise to the top of the Buchholz relay chamber. At this stage, the oil level in the relay changes the position of the float, which in turn activates the alarm system.
Detection of Significant Faults
A serious internal failure, like a major short-circuit, can result in a dramatic and fast movement of transformer oil.
This sudden oil flow sets off the operating mechanism of the relay and activates its trip circuit. This allows the transformer to be disconnected from the power system to prevent further losses.
As a result, the relay provides two levels of protection, as follows, first alarm of possible fault formation and protection from the serious fault.
Types of Buchholz Relay
Choosing the necessary relay depends on the transformer design, connection requirements, and operational conditions. Dhruti Sales provides different types of Buchholz Relay for transformer applications.
Buchholz Relay GOR-1
The Buchholz Relay GOR-1 is classified as a 25 mm eco magnetic switch that includes a CI (cast iron) body. Also, there are other types of the product, namely GOR-I-M with aluminum body and GOR-1M with a ports configuration.
Those variations provide the necessary options for different purposes and installation scenarios.
Buchholz Relay GOR-2
Buchholz Relay GOR-2 is a type of eco magnetic switch operating in the 50 mm range BI. This product line includes GOR-II-M which is available in aluminium body, as well as GOR-2M making use of magnetic reed switch.
With the 50 mm operating size, this product can be considered for those who have difficulties in making connections to the transformer.
Buchholz Relay GOR-3
According to the specifications provided on the product page of Buchholz Relay GOR-3, it is known to belong to the type of eco magnetic switch operating under the 25 mm range BI. GOR-3-M with aluminium body and GOR-3M utilizing the type of magnetic reed switch are also included in the line up.
It is possible that other variations exist allowing users to choose the most suitable configuration meeting the requirements of the transformer.
Key Features of Buchholz Relay
Properly chosen protection relay for transformer provides the following significant benefits:
Provides detection of emerging internal failures of the transformer
Provides alarm and trip protection
Can signal on gas formation in transformer oil
Can provide information on abnormal oil flow
Is installed between the main tank and the conservator of transformer
Helps reduce the risk of extensive transformer damage
Supports safer and more reliable transformer operation
What Makes Buchholz Relay Significant in Transformer Protection?
Transformers occasionally suffer from internal faults that may not present themselves externally. If left unattended, these may compromise damaged insulation, winding, transformer oil, and other components of the transformer structure.
The Buchholz relay affords additional protection against internal faults through detection of gas formation due to fault and abnormals in oil movement. This gives early alarm indication, enabling operators to inspect faults and help disconnect the transformer in the event of serious internal faults.
That is why Buchholz relay becomes especially relevant in oil-immersed transformers with a conservator.
Where Can Buchholz Relay Be Applied?
Buchholz relay is mainly associated with oil transformers and reactors. Its application fields include:
The specific configuration of the relay depends on the scheme of transformer design, size of the connection, method of protection, and manufacturer requirements.
What to Consider When Choosing the Buchholz Relay?
Before purchasing the relay, consider the following factors:
Connection size: Verify that you need a 25-mm or 50-mm connection.
Body Material: Depending on the application, available configurations may include cast iron or aluminum body options.
Switch Configuration: Magnetic and magnetic reed switch variants may be available for different control and monitoring needs.
Transformer Specification: Always match the relay with the transformer specifications, meaning do not choose any model based only on the physical size.
Dhruti Sales offers GOR-series Buchholz relay options that can help transformer makers, electrical contractors, and industrial buyers choose their preferred configuration option.
How to Maintain Buchholz Relay
Regular inspection is crucial when it comes to ensuring proper transformer protection. The maintenance crew should check the relay periodically, along with its alarm and trip circuits and connections.
Any unusual alarm indication must be thoroughly checked out because it may indicate that some internal transformer fault is developing.
In Conclusion
A Buchholz Relay is a significant protection device for oil-type transformers with the conservator type of arrangement. Being able to detect gas accumulation and abrupt oil movement, it can serve as a warning of developing faults and help disconnect the transformer.
The GOR-1, GOR-2, and GOR-3 series from Dhruti Sales feature various connection sizes and switch/body configurations for transformer protection purposes.
It is crucial for transformer makers, electrical contractors, utility companies, and industrial users to choose the correct Buchholz relay for transformer when constructing a reliable transformer protection system. The proper relay should always be selected based on the technical characteristics of the transformer and its protection requirements.
