What is a potential transformer

Instrument transformers are high accuracy class electrical devices used to isolate or transform voltage or current levels. The most common usage of instrument transformers is to operate instruments or metering from high voltage or high current circuits, safely isolating secondary control circuitry from the high voltages or . Primary of this transformer is connected across the phase and ground. Just like the transformer used for stepping down purpose, potential transformer i. PT has lower turns winding at its secondary.

The potential transformer is connected in parallel with the circuit.

The primary windings of the potential transformer are directly connected to the power circuit .

One of the major difference between them is that the current transformer convert the high value of current into low value whereas the potential or voltage transformer convert the high value of voltages into low voltage. Some other differences between the current and the potential transformer are explained below in the the . This is because measuring meters or instruments and protective relays are low . Instrument Transformers How will you measure AC currents and voltages of very high magnitude? You will need the measuring instruments having higher range, which literally mean huge instruments. T can not be open circuited on any circumstance when it is under service. T is independent of the secondary circuit condit.

The original magnitude can be determined by just multiplying the result with the transformation ratio. Such specially constructed transformers . The secondary voltage is substantially proportional to the primary voltage and differs from it in phase by an angle that is approximately zero. Potential transformer working principle, how voltage control transformer works concept is explained in this video tutorial. Voltage ratio calibration for . Reduce current by current transformer.

Y at 1 rated voltage with 120V based ANSI burden. They may also be operated line-to-ground or line-to-neutral, at reduced voltage , ( of rated volts). BBS type fuse in the secondary to protect the transformer. With six exceptions these transformers are ANSI C57.

IEC Rated models are available. They transform the high voltage into low voltage adequate to be processed in measuring and protection instruments secondary equipment, such as relays and recorders). Need advice on selecting an instrument transformer ?