Philippine Electrical Code: Mandatory Rules, Permissive Rules, Explanatory Rules, and Appendices

The Philippine Electrical Code (PEC) is an essential set of standards and regulations that govern electrical installations in the Philippines. It aims to ensure the safety, reliability, and efficiency of electrical systems, protecting both property and human lives. The PEC is divided into various sections, including Mandatory Rules, Permissive Rules, Explanatory Material, and Appendices. This article provides an in-depth understanding of these components, helping electrical professionals, electricians, engineers, and enthusiasts navigate the complexities of the PEC effectively.

Mandatory Rules

Definition and Importance

Mandatory Rules in the PEC are those that specify actions that are either required or prohibited. These rules are characterized by the use of terms such as “shall” or “shall not.” Compliance with these rules is not optional; they are legal requirements that must be followed to ensure the safety of electrical installations.

Key Characteristics

  • Legally Binding: Mandatory rules are enforceable by law, and failure to comply can result in legal consequences, including fines or other penalties.
  • Safety-Centric: These rules are designed to prevent electrical hazards such as shocks, fires, and explosions.
  • Specific Requirements: Mandatory rules provide clear and precise instructions, leaving little room for interpretation.


  • Grounding and Bonding: The PEC mandates specific grounding and bonding requirements to ensure that electrical systems are safely connected to the earth, reducing the risk of electrical shock.
  • Wiring Methods: Specific methods and materials are prescribed for wiring installations to prevent overheating and potential fire hazards.
  • Overcurrent Protection: The code outlines the necessary protective devices to prevent overcurrent conditions that can damage electrical components and pose safety risks.

Permissive Rules

Definition and Flexibility

Permissive Rules in the PEC identify actions that are allowed but not required. These rules provide flexibility by offering options or alternative methods that can achieve compliance with mandatory rules. Permissive rules are characterized by the use of terms such as “shall be permitted” or “shall not be required.”

Key Characteristics

  • Optional Compliance: Permissive rules provide choices, allowing for professional judgment and situational adjustments.
  • Flexibility in Implementation: They offer alternative methods or materials that can be used to meet the same safety standards as mandatory rules.
  • Innovative Solutions: Permissive rules enable the use of new technologies or practices that can enhance the efficiency and effectiveness of electrical installations.


  • Alternative Wiring Methods: While the PEC specifies certain wiring methods, it may also permit the use of other methods that meet the same safety criteria.
  • Use of Protective Devices: Different types of overcurrent protection devices may be permitted, as long as they provide adequate safety measures.
  • Installation Practices: Certain installation practices may be allowed as alternatives to the prescribed methods, provided they do not compromise safety.

Explanatory Material

Purpose and Content

Explanatory Material in the PEC is provided in the form of Fine Print Notes (FPN). These notes offer additional information, references to other standards, or explanations related to a specific code rule. Although these notes are informative, they are not enforceable as requirements of the PEC.

Key Characteristics

  • Informational Only: Explanatory material provides context and clarity but is not legally binding.
  • Educational Value: These notes help electrical professionals understand the rationale behind certain rules and how to apply them effectively.
  • Cross-References: They often include references to related sections of the PEC or other relevant standards and guidelines.


  • Clarifications: Fine Print Notes may explain why a particular grounding method is required, providing background information on its importance for safety.
  • References: Notes might direct users to additional resources, such as industry standards or best practice guides, for further information on a specific topic.
  • Contextual Information: Explanatory material can provide historical context or technical details that enhance understanding of a rule’s application.


Non-Mandatory Guidance

Appendices in the PEC provide supplementary information that can be valuable for understanding and applying the code. However, they are not part of the enforceable requirements and are included solely for informational purposes.

Key Characteristics

  • Supplementary Information: Appendices offer additional details that support the main text of the PEC but are not mandatory for compliance.
  • Best Practices: They often include recommendations and best practices that can help improve the quality and safety of electrical installations.
  • Non-Binding: While useful, the information in the appendices is not legally required to be followed.


  • Technical Tables: Appendices may include tables with technical data, such as conductor ampacities or voltage drop calculations, to assist in the design and installation of electrical systems.
  • Safety Guidelines: Additional safety guidelines or checklists may be provided to enhance the safety measures already outlined in the mandatory rules.
  • Installation Examples: Practical examples of compliant installations can help illustrate how the rules should be applied in real-world scenarios.


The Philippine Electrical Code (PEC) is a comprehensive document that ensures the safety and reliability of electrical installations. Understanding the different components of the PEC—Mandatory Rules, Permissive Rules, Explanatory Material, and Appendices—is crucial for electrical professionals. Mandatory Rules are legal requirements that must be strictly followed, while Permissive Rules provide flexibility and alternative methods. Explanatory Material offers valuable context and educational insights, and Appendices provide supplementary information to aid in the effective application of the code. By familiarizing themselves with these aspects, professionals can ensure compliance with the PEC and contribute to safer electrical installations across the Philippines.

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