Hope this helps
An "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.
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Hammad Khan
University of Western Australia
AnswerAn '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.
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.
An on-load tap-changer must not break the supply to the transformer's windings while the transformer is on load. So it has a 'make-before-break' arrangement with its contacts -i.e. one contact moves to the second tap setting, before the second contact moves away from the first tap setting, while a reactor balances the load currents when the contacts are on different tap settings. An on-load tap changer is motor-driven, and can be operated automatically or manually.An off-load tap-changer does not require a make-before-break arrangement, because it is designed to be operated when the transformer is disconnected.
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.
well the difference mainly exists in the method of finding them , these are :-1. in finding DC load line :-open all AC sourcesopen all the capacitors2. for AC load line:-open all the Dc sourcesshort all the capacitors.
OCTC means off circuit tap changer (off load tap changer) and OLTC means on load tap changer. in octc we can change the tap position while the transformer is in off condition only. we can not change the tap position of octc in charged condtion of the transformer. the tap position of octc can be change in deenrgise condion of transformer only means if you nwant to chang the tap position firstly you will have to deenrgise the power transformer then you can change the tap position of octc.while in oltc we can change the tap position of OLTC in charged condition of power transformer. This is the basic diffirence between OCTC and OLTC.generally the OCTC used in single phase generating transformer (G.T.Power Transformer) and OLTC used in three phase powwer transformers like standby transformer and auto transformer in power plants and switch yards. for any other question please mail me at (ashu_uit2007@yahoo.co.in )
No, the transformer has to supply the load, whether it is light or heavy.
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.
An on-load tap-changer must not break the supply to the transformer's windings while the transformer is on load. So it has a 'make-before-break' arrangement with its contacts -i.e. one contact moves to the second tap setting, before the second contact moves away from the first tap setting, while a reactor balances the load currents when the contacts are on different tap settings. An on-load tap changer is motor-driven, and can be operated automatically or manually.An off-load tap-changer does not require a make-before-break arrangement, because it is designed to be operated when the transformer is disconnected.
Depends on the rating of the transformer and the running load of the houses connected to it.
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.
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.
Because a transformer is a big lump of metal that takes time heat up, so if the load is on and off in a short time, the load rating can be exceeded.
No. All a tap changer (whether 'off-load' or 'on-load') does is to make minor changes to the turns-ratio of a transformer.
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.
It could be a couple of things. Voltage drop is one, if the distance of the load is too far from the source of power this will happen. The other thing is if you are using a step down transformer and it is under sized, as soon as you apply the load the transformer output will drop off. If this condition lasts the transformer will eventual fail.
remove load off transformer and check voltage.
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.