Types and Classification of Faults on Electrical Power Systems

Question: How many types of faults exist on the power system and how they are classified?

Answer: Generally four types of faults exist and are classified into two categories.

Symmetrical faults: They give rise to symmetrical equal currents having a displacement of 120°.

Unsymmetrical faults: They gave rise to unsymmetrical currents having unequal displacements.

List contains:

  1. Line to line to line fault
  2. Line to ground
  3. Line to line
  4. Double line to ground

Types of Fault


Severity of Fault

3 Line


Most Dangerous

Line to Line

Unsymmetrical Fault

More Dangerous

Line to Ground

Unsymmetrical Fault

Least Dangerous

Double Line to Ground

Unsymmetrical Fault

Dangerous than Line to Line and Line to Ground Fault


Author: Ankit Modi

I have received my M.Tech. (Power Electronics, Machines and Drives) and B.E. (Electrical Engineering) degrees in the year of 2013 and 2010 respectively. I have worked as a lecturer in C. K. Pithawalla College of Engineering and Technology, Surat for 2 years. I am currently working as an assistant professor in Electrical Engineering Department in Sankalchand Patel College of Engineering, Visnagar since May-2014.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s