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
    • Standards
    • Basics
    • Formula
    • Erection & Commissioning
    • Process Fundamentals
    • Root Cause Analysis
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
Search
  • Courses
  • PLC
  • Control Systems
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Reading: Comparison of Electrical Protection Relays
Share
Notification Show More
Font ResizerAa
Inst ToolsInst Tools
Font ResizerAa
  • Courses
  • PLC
  • Control Systems
Search
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Standards
    • Basics
    • Formula
    • Erection & Commissioning
    • Process Fundamentals
    • Root Cause Analysis
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Inst Tools > Blog > Electrical Basics > Comparison of Electrical Protection Relays

Comparison of Electrical Protection Relays

Learn the comparison of electrical protection relays with brief details such as function, application, advantages, and disadvantages.

Last updated: October 29, 2023 7:17 am
Editorial Staff
Electrical Basics
No Comments
Share
5 Min Read
SHARE

Learn the comparison of electrical protection relays with brief details such as function, application, advantages, and disadvantages.

Contents
Electrical Protection RelaysComparison of Protection Relays

The electrical protection relays play a critical role in electrical systems by monitoring various parameters and ensuring system safety by triggering corrective actions such as circuit isolation or alarm activation.

Electrical Protection Relays

Comparison of Electrical Protection Relays

The field of electrical and electronics engineering often encounters different types of protection relays, each designed to serve specific purposes.

In this article, we will discuss the following types of electrical protection relays.

  1. Overcurrent Relay
  2. Differential Relay
  3. Distance/Impedance Relay
  4. Earth Fault Relay
  5. Voltage Relay
  6. Frequency Relay
  7. Reverse Power Relay
  8. Thermal Relay
  9. Motor Protection Relay
  10. Directional Relay
  11. Synchronizing Relay
  12. Reclosing Relay

Comparison of Protection Relays

In the below table, you can easily learn the different types of protection relays with brief details such as function, application, advantages, and disadvantages.

S.No.Protection RelaysFunction and ApplicationAdvantagesDisadvantages
1Overcurrent RelayMonitors current levels and isolates the circuit if current exceeds a predetermined limit.Simple, cost-effective, and widely applicable.Slower operation and limited to overcurrent protection.
2Differential RelayCompares current entering and exiting a system component to detect internal faults.High sensitivity and speed for internal fault detection.Complex setting and limited to specific portions of a system.
3Distance/Impedance RelayMonitors the impedance (voltage/current ratio) between the relay and potential fault point.Can provide zone-wise protection and useful for long transmission lines.Sensitive to system parameters like load, leading to incorrect operations.
4Earth Fault RelayDetects earth faults in a system by monitoring residual or zero-sequence currents.Quick and reliable earth fault detection.May require separate overcurrent protection and can be sensitive to CT (Current Transformer) inaccuracies.
5Voltage RelayActivates upon detecting under-voltage or over-voltage conditions.Simple design and effective in protecting against voltage irregularities.Cannot differentiate between load-related and fault-related voltage changes.
6Frequency RelayMonitors the frequency of the electrical system and acts if it goes beyond set limits.Useful for generator protection and maintaining system stability.Not effective against other types of faults and might require coordination with other relays.
7Reverse Power RelayMonitors the direction of power flow, mainly used in generator protection.Helps in avoiding motoring action of generators.Limited application and generally used in conjunction with other protection methods.
8Thermal RelayProtects motors and transformers from overheating by monitoring temperature or thermal capacity.Effective in protecting equipment against thermal damage.Response time may be longer, and it cannot provide protection against fast-developing faults.
9Motor Protection RelayA specialized relay providing multiple protections like overcurrent, under-voltage, and phase imbalance for motors.Comprehensive protection for motors with features like auto-reset.More complex and expensive compared to simpler relays.
10Directional RelayFunctions like an overcurrent relay but considers the direction of the current flow.Useful in complex networks where current direction is important for fault identification.Requires correct phasing and is sensitive to system configurations.
11Synchronizing RelayEnsures that two AC generators or an AC generator and a utility can be synchronized safely.Enhances system reliability and allows for generator paralleling.Complex settings and usually applicable only to specific synchronization scenarios.
12Reclosing RelayAutomatically attempts to close a breaker after it has been opened due to a fault.Improves system reliability by enabling quick recovery from temporary faults.Not suitable for permanent faults, and multiple attempts can worsen the fault.

The selection of the right type of protection relay often depends on various factors, including the kind of equipment being protected, the nature of the electrical network, and the specific types of faults that are likely to occur.

If you liked this article, then please subscribe to our YouTube Channel for Electrical, Electronics, Instrumentation, PLC, and SCADA video tutorials.

You can also follow us on Facebook and Twitter to receive daily updates.

Read Next:

  • Single Core and Multi-Core Cables
  • Difference Between HV and LV Cables
  • Types of Cables in Industrial Automation
  • Instrumentation Cables Testing Steps
  • Flame Resistant and Retardant Cables
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

Difference Between Trunking and Conduit
Difference Between AA and AAA Batteries
What is a Ground Rod?
Why is the Humming Sound Produced in Transformer?
Bus Riser in Switchgear
Why is Motor Control Required in Control Systems?
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
208kSubscribersSubscribe
38kFollowersFollow

Categories

Explore More

Advantages of Three Phase System Compared to Single Phase System
What is Electrical Conduit? Types, Advantages, Disadvantages
Circuit Breaker Making Capacity
Electrical Substation – Busbar Arrangements and Layouts
Totally Enclosed Fan Cooled (TEFC) Motors Rampant Winding Burnouts
Current Transformer Selection, Operation & Maintenance
Difference between Servo Motor and DC Motor
NO vs NC Contact

Keep Learning

Dahlander Motor

Dahlander Motors – Principle, Advantages, Disadvantages

Characteristics of Protective Relay

What is a Protective Relay? Principle, Advantages, Applications

What is a Current Transformer

What is a Current Transformer?

Advantages of Valve Regulated Lead Acid (VRLA) Batteries

Advantages of Valve Regulated Lead Acid (VRLA) Batteries

Star and Delta Wiring Animation

Basics of Star and Delta connections

What is Air Circuit Breaker

What is an Air Circuit Breaker? Working Principle & Applications

Electrical Link Box

What is a Link Box?

Trip Circuit Breakers

How Do Electrical Shorts and Ground Faults Trip Circuit Breakers?

Learn More

Fine wire strain gauge

Fine Wire Strain Gauge Principle

Pressure Transmitter Basics

Pressure Transmitter Applications

Smart HART Transmitter

Analysis of HART communicator and Smart HART Transmitter

Field Transmitter Installation

Cables and Cable Glands Questions and Answers

Difference between Availability, Reliability & SIL

Difference between Availability, Reliability & SIL

Traces in TIA Portal

What is Trace Function in Tia Portal?

Electric Circuits Objective Questions

Electric Circuits Objective Questions – Set 10

trip solenoid installed on a control valve appears

SIS Final Control Elements

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?