pacbasics

2 Key Metrics in Overcurrent Protection: Why Time-Current Curves and Coordination Time Intervals Matter More Than You Think

TCC and CTI are the two most common acronyms in overcurrent protection coordination. Understanding Time-Current Curves Preventing human injury, limiting…

4 weeks ago

Transformer Tertiary Winding Basic Application

Tertiary winding in transformers have been widely used in the transmission and distribution of electricity - from power transformers up…

5 years ago

How Do Reclosers Work? Settings and Operation

Photo Credit: NOJA Power Reclosers, otherwise known as autoreclosers (derived from "automatic reclosing" capability) or ACRs (Automatic Circuit Reclosers) have…

5 years ago

Impedance-Based Fault Location | A Step-by-Step Guide

Impedance-based fault location is widely used throughout the power transmission and distribution industry. In fact, for most numerical relays, one-ended…

5 years ago

Distance Relaying Fundamentals | What is Apparent Impedance?

In our introductory article on distance relaying, we presented a simple apparent impedance calculation for a phase-to-phase fault on a…

5 years ago

ETAP Star Coordination on Focus | Detailed Example

The main objective of any protection system is to interrupt short-circuits as fast as possible. The means to achieve this…

6 years ago

Development of IDMT Relay Curves

Inverse Definite Minimum Time (IDMT) overcurrent relays operate when current exceeds the pick-up value and with an operating time that…

6 years ago

Practical Evaluation of a Power Fuse Interrupting Capacity

The selection of the short-circuit rating of power fuses and low voltage circuit breakers are treated differently than medium and…

6 years ago

Overcurrent Protection Devices and their Time Current Curves

Understanding overcurrent protection device characteristics is very important in a protection coordination study. To start our discussion on common overcurrent…

6 years ago

kAIC Rating Assessment of an Electrical Recloser

Electrical reclosers are widely used in overhead electrical distribution systems to detect and interrupt momentary faults mostly due to vegetation,…

6 years ago