Chapter 4 - Philippine Electrical Code (PEC) Overview

Philippine Electrical Code (PEC) Overview

• The PEC’s rules ensure electricity is used safely by people and regarding property
• PEC is divided into two sections
• PEC I covers electrical installations inside buildings
• PEC II covers electrical installations outside buildings

Adequacy

• Strict compliance with the code for safety in electrical installations and construction
• Does not guarantee efficiency, convenience, or adequacy for future expansion regarding electrical use

Categories of PEC Rules

• Mandatory rules use "SHALL"
• Mandatory rules are strictly followed for compliance and safety
• Advisory rules use "SHOULD"
• Advisory rules are recommendations but not mandatory

Safe Use of Electricity

• Establishes material standards and electrical work standards
• Ensures safe electricity usage for various needs, including light, heat, power, communications, signaling, and other applications

Legal Basis and Mandates

• PEC is mandated by Republic Act (R.A.) 7920, or R.A. 184, the New Electrical Engineering Law
• Referral codes are mandated by respective laws
• P.D. 1096 is the National Building Code
• P.D. 1185 is the Fire Code of the Philippines
• Structural Code under R.A. 7920 provides comprehensive regulations for electrical engineers and electricians practicing, licensing, and registration

Objectives

• Government authorities implement PEC
• Office of the Building Official implements PEC
• Office of the City Electrician implements PEC
• Office of the Municipal Electrician (or Electrical Supervising Engineer) implements PEC
• Regional Office of the DOLE implements PEC

PEC Scope

• Covers electrical conductors including optical fiber cables installed within or on, coming to or from:
• Public and private buildings
• Electrical generating plants
• Temporary and permanent substations
• Industrial plants
• Transformer stations
• Railway switchyards
• Yards, carnivals, and parking areas
• Watercraft, Dockyards, and Airfields
• Quarries and mines
• Mobile homes, travel trailers, and recreational vehicles
• Offshore facilities
• Other premises needing electrical installation

PEC Exclusions

• PEC does not apply to:
• Aircraft
• Motor vehicles
• Railway rolling stock

Permits and Inspection Certificates

• A permit is needed before electrical installations
• An inspection happens after installation
• A Certificate of Final Electrical Inspection (CFEI) is issued after a successful inspection

Exceptions to Permit Requirement

• A permit is not needed for:
• Installing rated electrical portable equipment up to 1,200 VA
• Reconnecting disconnected service due to non-payment or change of occupants, after one year

Electrical Permit Requirements

• Needed Form: DPWH form No. 77-001-E
• Application accomplished, signed, and submitted by a Professional Electrical Engineer
• If not exceeding 20 lighting/receptacle outlets or 4000 volt-amperes, 230 volts, can be prepared, signed, submitted by Registered Electrical Engineer or Master Electrician
• Application includes name, signature, and seal of the electrical practitioner in charge and signature of the owner or representative
• Five sets of plans and specs with the seal/signature of responsible Professional Electrical Engineer must be submitted
• If not exceeding stated limits, five sets of sketches and bill of materials done by Registered Electrical Engineer or Master Electrician
• No plans needed for buildings of indigenous materials or cost not more than P15,000.00, as per P.D. 1096

Electric Circuits in Buildings - Services

• Generally, a building or structure has only one service
• Exceptions include:
• Fire pump requires separate service
• Emergency electrical system requires separate service
• Multiple-occupancy building
• Capacity Requirements: Two or more services permitter where requirements more than 2,000 amperes at a supply voltage of 600 volts or less, or where single-phase load needs are more than the serving agency typically supplies
• Building area of 10,000 m^2 or more total area
• For different voltage characteristics or different uses (different rate schedules)

Overhead Service-Drop Conductor

• Defintion: Overhead service conductor from the last pole or aerial support, with splices, to entrance conductors at the building
• General: Sufficient ampacity to carry the load without detrimental temperature rise and adequate mechanical strength
• Minimum Size: Not smaller than 8 mm^2 copper or 14 mm^2 aluminum, or copper-clad aluminum

Clearances - Overhead Service-Drop Conductor

• Above Roofs: Vertical clearance of not less than 2,500 mm from the roof surface
• Vertical Clearance from Ground:
• 3,100 mm: At the electric service entrance to buildings, at the drip loop, or above sidewalks
• 3,700 mm: For areas listed in the 4,600 mm classification when the voltage is limited to 600 volts to ground
• 4,600 mm: Over residential property and driveways, and commercial areas not subject to truck traffic
• 5,500 mm: Over public streets, alleys, roads, parking areas subject to truck traffic, driveways on other than residential property, and other land traversed by vehicles (cultivated, grazing, forest, and orchard).

Underground Service-Lateral Conductor

• Definition: Underground service conductor between the street main and the first connection to the service-entrance conductors in a terminal box, meter, or other enclosure
• Insulation: Must withstand exposure to atmospheric and other conditions without detrimental current leakage

Exceptions

• Grounded conductor can be uninsulated
• Bare copper in a raceway
• Bare copper for direct burial where suitable for soil conditions
• Bare copper for direct burial as part of a cable assembly identified for underground use
• Aluminum or copper-clad aluminum without insulation as part of a cable assembly identified for underground use in a raceway or for direct burial

Underground Service-Lateral Conductor - Size and Rating

• General: Sufficient ampacity to carry the current for the load and adequate mechanical strength
• Minimum Size: Not smaller than 5.5 mm^2 copper or 8.0 mm^2 aluminum or copper-clad aluminum
• Where two to six service disconnecting enclosures supply separate loads from one service drop or lateral, one set of service entrance conductors permitted to supply each or several such service equipment enclosures

Underground Service-Lateral Conductor - Size and Rating Exceptions

• Exception: For installations to supply only limited loads of a single branch circuit, they shall not be smaller than 3.5 mm^2 copper or 5.0 mm^2 aluminum or copper-clad aluminum

Service Entrance

• The portion of the supply from the street main/transformer to the building supply, the conductors/equipment for power to the premises
• Types include
• Overhead Service Entrance: Most common, company provides overhead service cable between the building property line
• Underground Service Entrance: Raceway conduit from building to property line, Underground Service Entrance cable (USE) is recommended

Exceptions - Service Entrance

• Buildings with more than one occupancy
• Where two to six service enclosures grouped at one place supply loads from a service drop/lateral

Service Entrance - Size and Rating

• Conductors must sufficiently carry the computed loads
• Ungrounded conductors not smaller than:
• 100 A for one-family dwelling with six or more 2-wire branch circuits
• 60 A for one-family dwelling with initial computed load of 10 kVA or more
• 40 A for other loads

Service Entrance - Size and Rating Exceptions

• Consisting of not more than 2 – wire branch circuits, 5.5 mm^2 copper or 8.0 mm^2 aluminum or copper-clad aluminum
• By special permission, for loads limited by demand or supply source, 5.5 mm^2 copper or 8.0 mm^2 aluminum or copper-clad aluminum
• For limited loads of single branch circuit, 3.5 mm^2 copper or 5.5 mm^2 aluminum or copper-clad aluminum

Installation of Service Conductors

• Service entrance conductors installed per Code, using:
• Open-wiring on insulators
• Rigid Metal Conduit (RMC)
• Intermediate Metallic Tubing (IMT)
• Electrical Metallic Tubing (EMT)
• Service-Entrance Cables
• Wireways, Busways and Auxiliary gutters
• Rigid Non-Metallic Conduit (RNMC)
• Cable Bus
• Mineral-Insulated Metal-Sheated Cable
• Type MC Cables

Protection

• Service entrance conductors subject to physical damage must be protected by
• RMC, IMC, and RNMC suitable for the location
• EMT
• Type MC cable or other approved means

Service Equipment - Disconnecting Means

• Service-disconnecting means to disconnect all conductors from entrance conductors
• Number not more than six switches in enclosure/switchboard for each set/subset of entrance conductors
• Must be inside/outside the building readily accessible near entrance conductor point
• Rating is related to load carried, one circuit not less than 15 amperes, two circuits not less than 30 amperes.
• One family dwelling: 60 A when initial computed load is 10 kVA or more, 100 A where consists of six or more 2-wire banch circuits
• Others: Not less than 40 amperes

Service Equipment - Disconnecting Means Notes

• Service means must simultaneously disconnect all ungrounded conductors, able to close on a fault, short-circuit protective
• Ungrounded conductor device in each ungrounded conductor
• Fuses must be an interrupting rating no less than maximum current at circuit supply terminals
• Circuit breakers must be free to open, an interrupting rating at supply terminals

Feeders and Mains - Essential Considerations

• Large installations: one feeder per floor
• Small installations: up to two feeders
• Motor feeders must be separate
• Feeders over 50 mm diameter conduit should not be used
• Feeders should be subdivided if bends/offsets because 50 mm conduit largest
• Feeders radiating from distributing panel get properly rated switch/circuit breaker
• Always put feeders/mains inside a conduit pipe as it carries high voltage

Parts of Standard Electrical Plan - General Notes/Specs:

• Compliance with the latest PEC edition for all authorities
• The nature of the service (voltage, phase, and frequency)
• Type of wiring approval for service entrance, feeders, branch circuits, control systems, fire protection, communication systems
• All relevant construction details

Parts of Standard Electrical Plan - Example:

• Compliance with PEC, building code, municipal ordinances, and Meralco
• Service type: 230 volts, 1 phase, 2 wire system, 60 hertz, with one service drop to the building
• Wiring method: EMT both exposed/embedded, Metal molding where concealed conduits impractical
• All materials and equipment for intended

Parts of Standard Electrical Plan - Location and Purpose

• Lighting and convenience outlet homeruns must use 2 sq. mm and 3.5 sq. mm
• B. Legend and Symbols
• Legend shows symbols/configurations of the needed devices
• Standard symbols are in the Appendix A in the PEC
• C. Location Plan - Location or site plan with structures and owner's land appropriate metric scale
• Bordering areas show public and well-known streets
• Location of service drop, equipment, nearest pole of utility company
• Clearance of drop path/structure wires to structures
• Lighting/power panel boards circuit breaker mounted, doors locked/directory card
• Junction boxes of proper sizes shall, convenient/inconspicuous
• Outdoor installations shall be weatherproof
• All electrical work is under the supervision of a licensed Electrical Engineer