What is Buchholz relay and explain where it is used?
It is a type of oil and gas actuated protection relay. It is used for the protection of a transformer from the faults occurring inside the transformer, such as impulse breakdown of the insulating oil, insulation failure of turns etc.
What is the advantage of Buchholz relay?
Advantages of Buchholz Relay It is the simplest form of transformer protection. A Buchholz relay is a fundamental device for transformers, it keeps internal gas accumulation and oil flow monitored and under control. It detects incipient faults much earlier than the other forms of protection.
Why is Buchholz relay tripped?
Nuisance tripping of a Buchholz relay is common enough. If the level of oil in the conservator has been allowed drop beneath the outlet of the Buchholz relay, especially possible if the transformer has been off for so long unmonitored.
Do all transformers have a Buchholz relay?
Buchholz protection is normally provided on all transformers fitted with a conservator. The Buchholz relay is contained in a cast housing which is connected in the pipe to the conservator, as in figure shown.
What is the function of conservator in transformer?
The function of a conservator is to take up contraction and expansion of oil without allowing it to come in contact with outside air.
What is the function of the top float switch of the Buchholz relay in the transformer?
As gas bubbles migrate along the pipe, they enter the Buchholz relay and rise into the top chamber. As gas builds up inside the chamber, it displaces the oil, decreasing the level. The top float descends with oil level until it passes a magnetic switch which activates an alarm.
For what type of fault does Buchholz relay is employed?
Detailed Solution. Buchholz relay is used for the protection of transformers from the faults occurring inside the transformer. Short circuit faults such as inter-turn faults, incipient winding faults and core faults may occur due to the impulse breakdown of the insulating oil or simply the transformer oil.
Why is busbar protection needed?
To maintain system stability, the primary objective of busbar protection is to limit damage and remove busbar faults before back-up line protection. A low impedance differential system used to have a relatively long operation time.
What angle is Buchholz relay place in transformer?
2.5 to 5 degree angle
The Buchholz Relay is fitted in the pipework between the transformer itself and the conservator at a 2.5 to 5 degree angle. During normal transformer operation the relay allows oil flow between the conservator and the main tank and it is filled with oil.
What is the purpose of backup protection?
The backup protection provides the backup to the main protection during a short circuit whenever it fails in operation or is cut out for repairs. The backup protection is essential for the proper working of the electrical system.
What is the function of radiator in transformer?
The radiator of transformer accelerates the cooling rate of transformer. Thus, it plays a vital role in increasing loading capacity of an electrical transformer. This is basic function of radiator of a power transformer.
Why bushing is used in transformer?
In electric power, a bushing is a hollow electrical insulator that allows an electrical conductor to pass safely through a conducting barrier such as the case of a transformer or circuit breaker without making electrical contact with it.