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

Determine the load - thevenins equivalent circuit, Determine the load - The...

Determine the load - Thevenins Equivalent Circuit: Determine the load for which the source shall transfer the maximum power if load is connected across the terminal A and B, u

Explain the importance of distributing frames, Q. Explain the Importance of...

Q. Explain the Importance of distributing frames? Basically four levels of cabling are used as displayed in Figure. At the subscriber end, drop wires are taken to a distributio

Determine tick of the material, Tick off the material, which is different f...

Tick off the material, which is different from the group (A) Constantan.            (B) Manganin. (C) Nichrome.               (D) Brass. Ans: Tick off the materi

Detection and handling of gas leakage, Detection and Handling of Gas Leakag...

Detection and Handling of Gas Leakage : If you are using a toxic gas or have a store for it you must have some devices to indicate the leakage, if any. Though numerous monitoring

Machine, explain inifinite bus

explain inifinite bus

Industrial approach of speed control dc series motor, industrial approach o...

industrial approach of speed control of dc series motor

Voltage, Voltage, current, and charge control: The collector-emitter c...

Voltage, current, and charge control: The collector-emitter current can be seen as being controlled through the base-emitter current (current control), or through the base-emi

What is an amplifier, Q. What is an amplifier? What are the various types o...

Q. What is an amplifier? What are the various types of amplifiers? AMPLIFIER: A circuit that increases the amplitude of the given input signal is an amplifier. A small a.c. sig

Define sigma-delta analog to digital converters, Define Sigma-Delta Analog ...

Define Sigma-Delta Analog to Digital Converters? Sigma-Delta ADCs have the benefit of being implemented almost totally in the digital domain.  They are extremely reliable, high

Determine the speed of the motor, Q. A 10-kW, 250-V dc shunt generator, hav...

Q. A 10-kW, 250-V dc shunt generator, having an armature resistance of 0.1and a field resistance of 250 , delivers full load at rated voltage and 800 r/min. The machine is now ru

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