Buchholz relay pdf detector

Detects the incipient faults at a stage much earlier than is possible withother forms of protection. The Buchholz relay is installed at the middle of the connection pipe between the transformer oil tank and the conservator, so that, upon a fault development inside a oil transformer, an alarm is set off or the transformer is disconnected from the circuit. Switches characteristics Rated voltage: 24  250V AC or DC Rated current: 0,5 A (10000 tests) Breaking capacity: 2 A AC (cos 0,4  25  50Hz) 2A DC (T L R 40 msec). Mechanical protection degree IP 54 Insulation 2000V 50Hz between terminals and earth for a 60 seconds time. The moving float actuates a switch contact so that the transformer is disconnected. The relay neither gives a warning signal or disconnects the endangered equipment. The lower float is not affected as from a certain gas volume the gas flows through a piping to the conservator. Short circuited core laminations Short circuits between phases Broken-down core bolt insulation. Insulating liquid flow Fault: A spontaneous incident generates a pressure wave moving in the direction of the conservator.

Protecting Oil Type Transformer with Buchholz Relay EEP

Protection Range The relay is particularly effective in case of: Falling oil level owing to leaks. Response: As the liquid level falls the top float moves downward. Cable gland 10 Drain plug Casing Non porous weatherproof compact casting of light aluminium alloy painted. Description 1-2 Release terminals 3-4 Alarm terminals 5 Earth terminal 6 Breather cock 7 Valve of pneumatic test 8 Mechanical test of the alarmrelease circuit 9. It is the simplest form of transformer protection. In the event of a fault, oil or insulations decomposes by heat, producing gas or developing an impulse oil flow.

Detects the incipient faults at a stage much earlier than is possible withother forms of protection. On request its possible to supply change-over switches. Insulating liquid flow Fault: A spontaneous incident generates a pressure wave moving in the direction of the conservator. Therefore, separate protection is needed for connecting cables. Switches characteristics Rated voltage: 24  250V AC or DC Rated current: 0,5 A (10000 tests) Breaking capacity: 2 A AC (cos 0,4  25  50Hz) 2A DC (T L R 40 msec). It is intended mainly for transformers or choke coils having a conservator vessel. Cover Non porous weatherproof compact casting of light aluminium alloy painted. During normal operation it is filled completely with insulating liquid.

Vibration test (in normal operative conditions) Oscillation amplitude: 2mm Time diagram: 0Hz  100Hz 30 sec. It is the simplest form of transformer protection. Inspection windows Special tempered glass with graduated scale in cm3. Max Buchholz (18751956) in 1921, relay is used to produce an alarm in case of incipient (ow-developing) faults in the transformer and to disconnect the transformer from the supply in the event of severe internal faults. On request its possible to supply change-over switches. If a fault occurs inside the transformer, the Buchholz relay responds as  follows: Gas accumulation Gas accumulation in Buchholz relay Fault: Free gas is available in the insulating  liquid.

BILSTEIN COM

Cover Non porous weatherproof compact casting of light aluminium alloy painted. The relay is built in the connecting pipe between the transformer tank and the  conservator. Inspection windows Special tempered glass with graduated scale in cm3. (75Hz) first signals of closing contacts 120 vertical vibrationssec. . The Buchholz relay operates even on very slight faults which are just in process of developing, so that greater damage may be prevented.

Insulating liquid loss Insulating liquid loss in Buchholz relay Fault: Insulating liquid loss due to leakage. Introduction to Buchholz Relay Buchholz relay is a gas-actuated relay installed in oil immersed transformers for protection against all kinds of faults. If the flow rate exceeds the operating threshold of the damper, the latter moves in flow direction. Function of Buchholz relay In the following the operation of a Buchholz relay is explained using the example of a double-float  Buchholz relay. The moving float actuates a switch contact (magnet contact tube). In the event of a fault, oil or insulations decomposes by heat, producing gas or developing an impulse oil flow. Insulating liquid flow Buchholz relay The upper and lower switching system form a functional unit in the single-float Buchholz relay. It can only be used with oil immersed transformers equipped withconservator tanks. Short circuited core laminations Short circuits between phases Broken-down core bolt insulation.

It is intended mainly for transformers or choke coils having a conservator vessel. The relay responds to the accumulation of gas or air inside the apparatus when the oil level is too low or the flow of oil unusually strong. Response: The gas in the liquid moves upwards, accumulates in the Buchholz relay and displaces the insulating liquid level.