PEC – Is Voltage Drop Calculation Required?

There are provisions in the Philippine Electrical Code stating the maximum voltage drop for branch circuits and feeders.

Philippine Electrical Code Part 1/Chapter 2. Wiring and Protection/Article 2.10 - Branch Circuits

FPN No. 4: Conductors for branch circuits as defined in Article 1.0, sized to prevent a voltage drop exceeding 3 percent at the farthest outlet of power, heating, and lighting loads, or combinations of such loads, and where the maximum total voltage drop on both feeders and branch circuits to the farthest outlet does not exceed 5 percent, provide reasonable efficiency of operation. See FPN No. 2 of 2.15.1.2(a)(3) for voltage drop on feeder conductors.

Philippine Electrical Code Part 1/Chapter 2. Wiring and Protection/Article 2.15 - Feeders
FPN No. 2: Conductors for feeders as defined in Article 1.0, sized to prevent a voltage drop exceeding 3 percent at the farthest outlet of power, heating, and lighting loads, or combinations of such loads, and where the maximum total voltage drop on both feeders and branch circuits to the farthest outlet does not exceed 5 percent, will provide reasonable efficiency of operation.

In the Philippines, seldom do you see voltage drop calculations in electrical project documentations. What is the requirement of the Philippines Electrical Code for voltage drop calculations?

In Article 2.20 - Branch-Circuit, Feeder, And Service Calculations, Table 2.20.1.3 Additional Load Calculation References, states that voltage drop calculation is mandatory for

  1. Fire Pumps, Section 6.95.1.7
  2. Sensitive Electrical Equipment, Section 6.47.1.4(d)

With the above provisions, voltage drop calculation is optional for any other installations. If you are the electrical designer, how would you guaranty that the cable selections are suitable for the project. I will answer this in my next article.