Inst ToolsInst ToolsInst Tools
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Search
  • Books
  • Software
  • Projects
  • Process
  • Tools
  • Basics
  • Formula
  • Power Plant
  • Root Cause Analysis
  • Electrical Basics
  • Animation
  • Standards
  • 4-20 mA Course
  • Siemens PLC Course
Reading: Transformer Operation Under No-Load
Share
Font ResizerAa
Inst ToolsInst Tools
Font ResizerAa
  • Courses
  • Design
  • PLC
  • Interview
  • Control System
Search
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Inst Tools > Blog > Electrical Theory > Transformer Operation Under No-Load

Transformer Operation Under No-Load

Last updated: August 7, 2018 3:09 pm
Editorial Staff
Electrical Theory
No Comments
Share
2 Min Read
SHARE

If the secondary of a transformer is left open-circuited (Figure 6), primary current is very low and is called the no-load current. No-load current produces the magnetic flux and supplies the hysteresis and eddy current losses in the core.

The no-load current (IE) consists of two components: the magnetizing current (Im ) and the core loss (IH). Magnetizing current lags applied voltage by 90°, while core loss is in phase with the applied voltage (Figure 1b). VP and VS are shown 180° out of phase. IH is very small in comparison with Im , and Im is nearly equal to IE . No-load current, IE , is also referred to as exciting current.

Transformer Operation Under No-Load

Figure 1 : Open-Circuit Secondary

Example:

When the secondary of a 120/440 V transformer is open, primary current is 0.2 amps at a PF of .3. The transformer is a 5 kVA transformer. Find: (a) IP ,  (b) IE   (c) IH , and (d) Im

Solution :

(a) Full Load Current = KVA Rating / Vp

(b) IP at no load current is equal to IE

(c) IH = IE Cos θ = IE  x PF

IH = 0.2 x 0.3 = 0.06 amps

(d) Im = IE Sin θ

θ = across 0.3 = 72.5°

Im = 0.19 amps

Don't Miss Our Updates
Be the first to get exclusive content straight to your email.
We promise not to spam you. You can unsubscribe at any time.
Invalid email address
You've successfully subscribed !

Continue Reading

What is Electricity ?
Parallel AC Generators
Capacitance and Capacitive Reactance
Power Triangle
Impedance
Calculate Power in Series RC Circuit
Share This Article
Facebook Whatsapp Whatsapp LinkedIn Copy Link
Share
Leave a Comment

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Stay Connected

128.3kFollowersLike
69.1kFollowersFollow
210kSubscribersSubscribe
38kFollowersFollow

Categories

Explore More

Resonance, Resonant Frequency, Series and Parallel Resonance
Series-Wound Motor
Kirchhoff’s Laws
DC Circuit Analysis Loop Equations
Moving Iron Vane Meter Movement
Voltmeters
Starting a Synchronous Motor
AC Generation Analysis : Effective Values, Phase Angle and Frequency

Keep Learning

Shunt-Wound DC Generator Principle

Shunt-Wound DC Generators

Wiring Diagram

Wiring Diagram

How to Measure Specific Gravity of Battery

How to Measure Specific Gravity of Battery

Chemical Battery

Batteries

Calculate Power in Series RL Circuit

Calculate Power in Series RL Circuit

Armature Current in a DC Motor

DC Motor Torque

Calculate Power in Series RCL Circuit

Calculate Power in Series RCL Circuit

DC Motor Connections

DC Motor Connections

Learn More

Automatic Box Filling System using PLC Programming

Automatic Box Filling System using PLC Programming

Common Valve Abbreviations

Common Valve Abbreviations in US Engineering Drawings

Limit, Selector, and Override controls

Limit, Selector, and Override controls

Measure Duty Cycle using Multimeter

How to Measure Duty Cycle using Multimeter

PID Controller Responses to Two momentary step inputs

PID Controller Response with different Input Signals

PLC Interview Questions and Answers

PLC Interview Questions and Answers

Hydrogen sulfide gas

Hydrogen Sulfide Gas (H2S)

remote seal capillary type dp transmitter

Closed Tank Remote Seal Capillary type DP Transmitter

Menu

  • About
  • Privacy Policy
  • Copyright

Quick Links

  • Learn PLC
  • Helping Hand
  • Part Time Job

YouTube Subscribe

Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Welcome Back!

Sign in to your account

Username or Email Address
Password

Lost your password?