What do you mean by instrument transformers, Electrical Engineering

Assignment Help:

Q. What do you mean by Instrument transformers?

These are generally of two types, potential transformers (PTs) and current transformers (CTs). They are designed in such a way that the former may be regarded as having an ideal potential ratio, whereas the latter has an ideal current ratio. The accuracy ofmeasurement is quite important for ITs that are commonly used in ac circuits to supply instruments, protective relays, and control devices.

PTs are employed to step down the voltage to a suitable level, whereas CTs (connected in series with the line) are used to step down the current for metering purposes. Often the primary of a CT is not an integral part of the transformer itself, but is a part of the line whose current is being measured. In addition to providing a desirable low current in the metering circuit, the CT isolates the meter from the line, which may be at a high potential. Note that the secondary terminals of a CT should never be open-circuited under load. The student is encouraged to reason and justify this precaution. One of the most useful instruments for measuring currents in the ampere range is the clip-on ammeter combining the CT with one-turn primary and the measurement functions.


Related Discussions:- What do you mean by instrument transformers

Explain continuous-data and discrete-data systems, Q. Explain Continuous-da...

Q. Explain Continuous-data and discrete-data systems? A continuous-data system is one in which the signals at various parts of the systemare all functions of the continuous-tim

What is effect of temperature on semiconductor conductivity, What is the ef...

What is the effect of temperature on conductivity of semiconductor? Electrical conductivity of semiconductor changes appreciably along with temperature changes. At absolute zer

Digital ttl circuit, Execution of Digital Logic Circuits A safety circ...

Execution of Digital Logic Circuits A safety circuit is employed on a lathe to prevent the motor turning if it is not safe to operate. A series of 2 switches are used to check

Design a pulse generator, To design a VI that can also be used as a Sub VI ...

To design a VI that can also be used as a Sub VI in another VI. The title of the VI will be Pulse Generator. The output from the VI will be of the type Analogue Waveform and

Sim set interrupt mask instruction, SIM Set Interrupt Mask Instruction ...

SIM Set Interrupt Mask Instruction This  instruction is used  to mask unmask 8085 interrupts and send  serial  output  data. The accumulator  is used to load the  require data

Components in a microprocessor, What are the basic components in a Micropro...

What are the basic components in a Microprocessor? 1) Address lines to refer to the address of a block 2) Data lines for data transmit 3) IC chips 4 processing data

Induction motor, principle and operation of 3phace induction motor

principle and operation of 3phace induction motor

Give the properties and application of cotton, Give the properties and appl...

Give the properties and application of cotton. Cotton : It is base material for insulating fibres. Properties: It can be enhanced by impregnating with varnish. 1)

Explain how to represent power lines, Explain How to Represent Power Lines?...

Explain How to Represent Power Lines? The equivalent circuit of a power line depends on the length of the line and on the accuracy of the model required. In general, any power

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd