The abbreviation, 'PT', stands for 'potential transformer' (in Britain, the abbreviation is 'VT', and stands for 'voltage transformer'). This, together with a 'current transformer', falls into a category of transformer known as 'instrument Transformers'.
A 'PT' or 'VT' is used to reduce a high voltage to a level of voltage that can be safely read, remotely, by regular a.c. voltmeters or to provide inputs to high-voltage protection relays, while electrically- isolating the secondary circuit from the high-voltage primary circuit for the purpose of safety.
Both are same.AnswerA 'PT' is a 'potential transformer', the preferred term in North America, for what is termed a 'VT', or 'voltage transformer', in Britain. Two names for exactly the same instrument transformer.
'CT' is used to designate current transformers, and 'PT' is used to designate potential transformers. A current transformer provides a ratio of primary current to the secondary. A potential transformer provides a ratio of primary voltage to the secondary. A power transformer (step up or step down) resembles a PT more than a CT.
A current transformer pushes a ratio of primary current in the secondary. A potential transformer pushes a ratio of primary voltage in the secondary. Shorting a CT allows the full current the CT wants to push to flow. Shorting a PT makes it very difficult for the PT to produce rated voltage. To keep the voltage at rated value, the PT would have to push ~infinite secondary current.
PT's are typically used for metering and relaying purposes to sample the power system voltage and phase angles. The primary is at line voltage, and the secondary is typically between 66 - 120 volts (depending on primary connection, Line to Line or Line to Neutral). So yes, PT's are step down transformers.
"main" purpose depends on who's wants it installed. There are several purposes for bus PTs - metering, relaying, indication to control centers, control (such as for a tap changer on a transformer), sync (typically breaker 1/2 and ring bus configurations). Line PT's can be used for all the above as well.
CT=========current transformer PT=========potential transformer these are the instrumental transformers.
Both are same.AnswerA 'PT' is a 'potential transformer', the preferred term in North America, for what is termed a 'VT', or 'voltage transformer', in Britain. Two names for exactly the same instrument transformer.
A capacitive voltage transformer (CVT) uses a (usually two) stacks of capacitors to reduce the votlage to a smaller internal potential transformer (PT). This makes them less expensive than an equivalent PT, but there can be a loss of accuracy.
A ct is a step up transformer where as a pt is a step down transformer because both are used for measurement and protection purpose . current is stepped down if the secondary windings are more so we can obviously say thar ct is step up transformer
'CT' is used to designate current transformers, and 'PT' is used to designate potential transformers. A current transformer provides a ratio of primary current to the secondary. A potential transformer provides a ratio of primary voltage to the secondary. A power transformer (step up or step down) resembles a PT more than a CT.
Transformer Motors CT,PT Genrators these all are electrical devices
A current transformer pushes a ratio of primary current in the secondary. A potential transformer pushes a ratio of primary voltage in the secondary. Shorting a CT allows the full current the CT wants to push to flow. Shorting a PT makes it very difficult for the PT to produce rated voltage. To keep the voltage at rated value, the PT would have to push ~infinite secondary current.
PT's are typically used for metering and relaying purposes to sample the power system voltage and phase angles. The primary is at line voltage, and the secondary is typically between 66 - 120 volts (depending on primary connection, Line to Line or Line to Neutral). So yes, PT's are step down transformers.
a PT, potential transformer, can be thought of as a pure transformer with primary and secondary windings; PT's are sometimes referred to as magnetic transformers due to the fact that their mode of operation is purely magnetic. It is used to step-down the input voltage from a power line to a voltage level that can be processed by metering devices and protection relays in a substation. CVT or CCVT, capacitor-coupled voltage transformer, is made with two capacitor sets acting as a voltage divider that brings the line (actually the phase) voltage down to around 12Kv then this voltage is fed to a relatively small transformer for the voltage signal to be processed. CVT is rated for extremely high voltage levels above 230KV, while PT's aren't designed for such large values. CVT's offer the advantage that the voltage divider capacitor, being itself relatively smaller and lighter, configuration makes the transformer's iron core much smaller in size, and hence more economical, versus what it would be if a pure magnetic transformer would be used. Also the CVT's can be tuned to the fundamental frequency of the line, and the capacitance prevents the inductive "fire-back" of the coils in the transformer when a breaker trips. PT's can't provide such advantage. some CVT's are also used to tune to PLCC, Programmable Logic Controller Carrier frequency, which is a signal transmitted over power lines providing inter-PLC communication.
Construction wise, in a live tank PT, both the primary & secondary windings will be placed on top tank. In a dead tank PT, primary & secondary windings will be placed in bottom tank.
"main" purpose depends on who's wants it installed. There are several purposes for bus PTs - metering, relaying, indication to control centers, control (such as for a tap changer on a transformer), sync (typically breaker 1/2 and ring bus configurations). Line PT's can be used for all the above as well.
A variety of electrical transformers are produced for a variety of purposes. All of the types use the same principle discovered by Michael Faraday, and employ many of the same parts. The various types include. Audio transformers, Instrument transformers, Pulse transformers, Power transformers, RF transformers. .