Arc Flash Equipment Labeling Requirement
Equipment labeling requirement for arc-flash were initially introduced in NEC 2002 and later in NFPA 70E 2009.Since then, it has become a norm not only in North America but in …
Short-circuit Apparent Power of the System
In this article, I have presented the effects of utility fault level on low voltage equipment. Assuming an infinite bus as the utility fault level will have a significant cost …
Effect of Utility Fault Level to Low Voltage Equipment Ratings
There are times that the Electrical Engineer are unable to get the utility fault level data to calculate the required electrical parameters for a project. In such case, it is …
Miniature Circuit Breaker Applications
Miniature circuit breakers despite being common in domestic use are not created equal. There are several types of MCBs with different tripping characteristics, each of which are designed for particular …
Lightning protection
Lightning is a high-voltage discharge (usually negative) within clouds (intra-), to each other (inter-), or to the earth. The cloud-to-ground (CG) flash is the one we are usually concerned with …
Earth-fault Factor – Importance in Equipment Selection
IEC 60071-1 [3.15] defines earth-fault factor k to be at a given location of a three-phase system and for a given system configuration, the ratio of the highest r.m.s phase-to-earth …