Standards and Statutory Laws
What do NFPA 70 and AS/NZS 3000 have in common? The former is National Electrical Code (U.S.) and the later is the Wiring Rules (Australia and New Zealand). Both are …
Voltage Drop Calculations
In 2008, I have written some articles on voltage drop calculations as a tool in the selection of the correct cable sizes. Voltage Drop Calculation; Voltage Drop Calculation Part 2; …
Time-Current Curves Using Excel 2013
This tutorial serves a guide for the creation of time-current curves using Excel 2013. The user is expected to have at least an intermediate level of knowledge in the usage …
Insulation Coordination – Why is it required?
What is insulation coordination and what is its importance? There are many definitions of insulation coordination provided by different authorities. In this instance we wanted to use IEC 60071-1 definition …
Grounding and Bonding Permitted Methods
Grounding is one of the most taken for granted provision of the Philippine Electrical Code. The incompetence of Electrical Inspectors make this practice worst. I inspected the grounding system of …
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 …