Importance of Surge Impedance Loading (SIL) in Transmission Lines
Introduction
The demand for power is steadily increasing every year, leading to a growing gap between power supply and demand. This gap can be addressed by either adding new generation units or expanding the existing infrastructure. However, power generation and demand vary across regions, with some regions experiencing a surplus and others a deficit. Efficient utilization of power involves transferring...
Significance of K factor in High VoltageCircuit Breaker Ratings
High Voltage Circuit Breaker Interrupting Rating
The interrupting ratings of a high-voltage circuit breaker are primarily defined by two parameters: the rated short-circuit current, I, and the rated maximum voltage, V, at which the breaker must interrupt I. These concepts are straight forward and widely understood. However, high-voltage circuit breakers also feature a lesser-known parameter called the voltage range factor,...
Philippine Electrical Code – Ambient Correction Factor for Cables
Temperature in the Philippines
According to PAGASA data, the average mean annual temperature across all weather stations in the Philippines, excluding Baguio, is 26.6°C. The coolest month is January, with an average temperature of 25.5°C, while May is the warmest month, averaging 28.3°C. Latitude has little impact on temperature variations, whereas altitude significantly influences temperature. For instance, Baguio,...
Philippine Electrical Code – Objectionable Current
What is Objectionable Current?
The term "objectionable current" in the context of the Philippine Electrical Code (PEC) refers to the presence of current flow on grounding conductors or grounding paths that are not intended to carry current during normal operation. The PEC addresses objectionable current in Article 2.50.1.6, which highlights the need to minimize or eliminate such currents because...
Philippine Electrical Code – General Requirements for Grounding and Bonding
Performance-based requirements establish overall objectives without prescribing specific methods to achieve them. The opening paragraph of Section 2.50.1.4 explains that the performance objectives outlined in 2.50.1.4(A) for grounded systems and 2.50.1.4(B) for ungrounded systems can be met by adhering to the detailed prescriptive requirements set forth in Article 2.50 - Grounding and Bonding.
Section 2.50.1.4 does not dictate specific rules...
