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On-load tap-changers are operated by an electric motor, often by driving a flywheel mechanism. The operation of the tap-changer is controlled by an AVR (automatic voltage regulator) which monitors the transformer's secondary voltage.
Wiki User
∙ 11y ago
Wiki User
∙ 14y agoIf you change the taps you will set the desired voltage like 415v, 440v. but for off load you have to take a total electrical shut down.
Voltage control for transmission & distribution is obtained by tap changing. This can be done at various levels. occasional adjustment of voltage ratio is done by off load tap changer. Daily & short time voltage control is not possible by off load tap changer.
Daily voltage variation due to changing load & short period variations are controlled by ON-LOAD TAP Changer. It provides automatic regulation of bus bar voltage.
Wiki User
∙ 12y agoAn 'off load' tap changer is one that can only be operated when the transformer is disconnected.
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Why it is necessary to disconnect the load when change the tap?
when the load is connected to draws some current. while changing the tap of the transformer the tappings related to the winding is changed , so the load current affects the transformer. hence while changing the tap it should be noted thatAnswerThere are two types of tap-changing mechanism -'off-load' and 'on-load'. Off-load tap changers physically disconnect the winding when changing from one tap setting to the next. Accordingly, the circuit is temporarily broken, and dangerous arcing will take place if the transformer is energised. Therefore off-load tap changers require that the transformer is disconnected while the mechanism is operated.On the other hand, 'on-load' tap changers use a mechanism which incorporates a 'make before break' contact arrangement, ensuring that no break is made in the circuit as the mechanism moves from one tap setting to the next, enabling it to operate with the transformer energised and supplying load. On-load tap changers are usually automatically operated, although this feature can be overridden and operated manually.
Why tapping are provided in high voltage winding of transformer?
Tappings are provided in order to make small adjustments to the turns ratio, so that the secondary voltage can be increased or reduced, if required, in order to meet the relevant statutory voltage variation requirements.Tap changing mechanisms may be 'off-load' or 'on-load' types.With off-load tap changers, the transformer must be de-energised before the tap-changing mechanism is altered, as the mechanism breaks the connection to the windings as it is changed.With on-load tap changers, the mechanism is adjusted (usually automatically, when required) with the transformer energised and supplying load. The mechanism is installed on the high-voltage side of the transformer (regardless of whether it is a step up or step down transformer) because the high-voltage windings carry the lower current, allowing smaller contacts to be used. On-load tap changers use a 'make-before-break' arrangement, so that the windings are never disconnected when the mechanism changes its tap setting.
What is the use of tap changing switch?
To make minor adjustments to the transformer's turns ratio in order to slightly increase or decrease the secondary voltage in order to maintain that voltage within legal requirements. Off-load tap changers, as the name implies, can only be operated when the transformer is disconnected.
Why tap changer is required?
Tap changers are used to change transformer winding ratios by a specified amount (+/- 10%, for example). This allows more voltage control of one side with respect to the other. For a distribution transformer, as load increases, the voltage will sag. If it sags too far, a tap changer will be required to raise the voltage to acceptable values.
What is no load tap changing in transformer?
It changes the tap while it is operation (hence "on load"). This allows real-time voltage regulation for the transformer secondary (as load picks up, causing the voltage to sag, the LTC can tap up, increasing the voltage).
Why it is necessary to disconnect the load when change the tap?
when the load is connected to draws some current. while changing the tap of the transformer the tappings related to the winding is changed , so the load current affects the transformer. hence while changing the tap it should be noted thatAnswerThere are two types of tap-changing mechanism -'off-load' and 'on-load'. Off-load tap changers physically disconnect the winding when changing from one tap setting to the next. Accordingly, the circuit is temporarily broken, and dangerous arcing will take place if the transformer is energised. Therefore off-load tap changers require that the transformer is disconnected while the mechanism is operated.On the other hand, 'on-load' tap changers use a mechanism which incorporates a 'make before break' contact arrangement, ensuring that no break is made in the circuit as the mechanism moves from one tap setting to the next, enabling it to operate with the transformer energised and supplying load. On-load tap changers are usually automatically operated, although this feature can be overridden and operated manually.
What is on load tap chenger?
A tap changer is used to vary the turns ration between the windings of a transformer to make minor changes to the secondary voltage. An on-load tap changer enables the turns ratio to be altered without disconnecting the transformer. An off-load tap changer requires the transformer to be temporarily diconnected. On-load tap changers are installed on the high-voltage side of the transformer, where the current is lower.
Why there is a need to disconnect transformer while using off-load tap changer?
Changing off-load tap changers requires opening up the transformer, draining (at least some) oil, and manually changing electrical connections. None of these things can be done while the transformer is hot.
Why tapping are provided in high voltage winding of transformer?
Tappings are provided in order to make small adjustments to the turns ratio, so that the secondary voltage can be increased or reduced, if required, in order to meet the relevant statutory voltage variation requirements.Tap changing mechanisms may be 'off-load' or 'on-load' types.With off-load tap changers, the transformer must be de-energised before the tap-changing mechanism is altered, as the mechanism breaks the connection to the windings as it is changed.With on-load tap changers, the mechanism is adjusted (usually automatically, when required) with the transformer energised and supplying load. The mechanism is installed on the high-voltage side of the transformer (regardless of whether it is a step up or step down transformer) because the high-voltage windings carry the lower current, allowing smaller contacts to be used. On-load tap changers use a 'make-before-break' arrangement, so that the windings are never disconnected when the mechanism changes its tap setting.
What is the use of tap changing switch?
To make minor adjustments to the transformer's turns ratio in order to slightly increase or decrease the secondary voltage in order to maintain that voltage within legal requirements. Off-load tap changers, as the name implies, can only be operated when the transformer is disconnected.
Why tap changer is required?
Tap changers are used to change transformer winding ratios by a specified amount (+/- 10%, for example). This allows more voltage control of one side with respect to the other. For a distribution transformer, as load increases, the voltage will sag. If it sags too far, a tap changer will be required to raise the voltage to acceptable values.
What would an off load transformer tap changer be used for?
to inreases or decreases n. of turns of a transformerAnswerAn 'off-load' tap changer is a tap-changing mechanism that can only be used when the transformer is disconnected, as opposed to an 'on-load' tap-changing mechanism that can operate when the transformer is energised and on load.Tap changing is performed to slightly change the turns ratio of a transformer in order to keep the secondary voltage within the statutory limits (e.g. in the UK, 230 V +10% -6%) should there be a substantial change in load.
Difference between off load transformer and on load transformer?
Hope this helpsAn "OFF-Load tap transformer" can only have it's tap adjusted when it is De-energized,while the "On-Load tap transformer" can adjust its tap under load conditions.Kind RegardsHammad KhanUniversity of Western AustraliaAnswerAn 'off load' transformer is one whose secondary is open circuited, and not supplying a load. An 'on load' (not 'load') transformer is one that is connected to a load.
What is off load tap change?
Tap changer is a device that is used to change the secondary voltage on transformers. It is normally on the HV winding of the transformer. Off load tap changer is designed to change the taps only when the transformer is not charged, while on load tap changer is capable of changing the tap on load too.
What is the fucntion of tap windings in a power transformer?
A: Its sole function is to provide a voltage with a phase differential of 180 degrees from winding to winding with respect to the tap.AnswerTaps are simply connections part way along a coil. In the case of power transformers (i.e. transformers used in the transmission and primary distribution system), there are usually several tap connections along the high-voltage coil, which will allow minor variations to be made to the turns ratio of the transformer which, in turn, will enable corrections to be made to the secondary voltage in order to maintain that voltage within statutory limits as the load changes.Tap-changing mechanisms can be 'off load' or 'on load'. Off-load tap changers physically break the supply to the windings during the changeover, so must be performed with the transformer de-energised. On-load tap changers, on the other hand, use a 'make before break' arrangement with its contacts, so that tap changing can be performed with the transformer both energised and on load, and can be performed automatically or manually, to maintain the secondary voltage within its statutory range.In the US and Canada, but not in Europe, distribution transformers use a centre-tap 240-V secondary winding, which provides the neutral for residential supplies, with opposite ends of the winding having potentials of 120 V with respect to the centre tap.
Is an on-load tap changer considered as a resistor?
No. All a tap changer (whether 'off-load' or 'on-load') does is to make minor changes to the turns-ratio of a transformer.
What is the problem of operating a on-load furnace transformer with center tap?
What is the problem of operating a on-load furnace transformer with center tap
