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

Input offset voltage of operational amplifier, Q. Input offset voltage of o...

Q. Input offset voltage of operational amplifier? When both inputs are tied to ground, i.e., both differential-mode and common-mode inputs are zero, the output should be zero.

DLD, draw alogic diagramto implement F=ABCDE using only 3 inputAND gates

draw alogic diagramto implement F=ABCDE using only 3 inputAND gates

Determine the voltage across the capacitor, (a) Let a unit impulse of curre...

(a) Let a unit impulse of current i(t) = δ(t) be applied to a parallel combination of R = 3 and C = 1/2 F. Determine the voltage vC(t) across the capacitor. (b) Repeat (a) for

Di disable interrupts instruction, DI Disable  Interrupts Instruction ...

DI Disable  Interrupts Instruction The interrupt enable  flip flop is reset and all the  interrupts of 8085 microprocessors  except  TRAP  are disabled . the  instruction  form

Examples of attribute data relevant for a power utility, Examples of attrib...

Examples of attribute data relevant for a power utility: Examples of attribute data relevant for a power utility are given below. •          Consumer data such as categor

Design the synchronous sequential circuit for state diagram, Design the Syn...

Design the Synchronous Sequential Circuit for State Diagram Illustration: - We wish to design the synchronous sequential circuit whose state diagram The kind of flip-f

Principals applied in product design, What are the broad principals that wi...

What are the broad principals that will be applied in product design to facilitate automated assembly ?

Types of bias circuit for class a amplifiers, Types of bias circuit for Cla...

Types of bias circuit for Class A amplifiers: There are five common types of biasing circuits used with Class A bipolar transistor amplifiers: A. Fixed bias B. Collector

Find the percent voltage regulation of the transformer, Q. A 25-kVA, 2400/2...

Q. A 25-kVA, 2400/240-V, 60-Hz, single-phase transformer has an equivalent series impedance of 3.45 + j5.75  referred to the primary high voltage side. The core loss is 120 W. Whe

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