How to Make Your Home Electrical System Safe During Construction

Safe Electrical System for Your Home: What to Consider During Construction

A practical and engineering-based guide for homeowners building in tropical regions

Why Electrical Safety Is Non-Negotiable

When building a house, especially in countries like the Philippines with high humidity, strong rains, and unstable public grids, a safe and well-planned electrical system is essential. Poor design or installation can lead to:

Fire hazards

Short circuits

Equipment failure

Dangerous electric shocks

Premature cable degradation

1. Use a Licensed Electrical Engineer or Electrician

Never let general workers or "handymen" install your wiring.
Ensure you hire:

A PRC-licensed electrical engineer for system planning and load calculation

A licensed electrician for actual installation

Both should follow the Philippine Electrical Code (PEC) or international standards (IEC)

2. Plan Load and Circuit Distribution Carefully

Your house must have:

A clear load schedule (how many amps per room, per appliance)

Dedicated circuits for high-load equipment (air conditioners, heaters, ovens, pumps)

Separate lines for lighting, outlets, and kitchen loads

This avoids overloading and enables easy troubleshooting later.

Example:

2.0 HP aircon → separate 20–30 A breaker

Microwave, oven → own circuit

Bedrooms → 10–15 A each

3. Use the Right Materials

Wires:

Use copper, not aluminum

Minimum wire size for outlets: 2.0 mm²

For aircon/heavy loads: 3.5–5.5 mm²

Use heat and moisture-resistant cables (e.g. THHN or TW types)

Breakers:

Only use known brands: Schneider, ABB, Panasonic, Siemens

Avoid "no-name" breakers from cheap hardware stores

Main breaker must match total load + 25–30% margin

Panel Board:

Proper enclosure (metal, earthed)

Accessible but protected location

Labels for all circuits

4. Install a Proper Grounding System

A safe grounding system prevents shock and protects your equipment.

Use ground rods at least 2.4 meters long

Ground the main panel, appliance chassis, and metal fixtures

Bond all grounds together (equipotential bonding)

Use green wires for grounding, color-coded by standard.

5. Include RCD (Residual Current Device) / ELCB Protection

Install RCDs or RCCBs to cut off power in case of leakage current (e.g. water + electricity = fatal risk).

30 mA trip sensitivity

Install per room or per sensitive area (bathroom, outdoor, kitchen)

Combine with MCBs in your panel

This is a life-saving component, not optional.

6. Avoid Common Installation Mistakes

Running wires directly in cement without conduit

No junction boxes or open splices

Loose or unlabelled breakers

Undersized wires or cheap breakers

Exposed cables in damp areas

Always install all wires in conduit (PVC or flexible) – underground and surface.

7. Integrate Solar and Backup Systems Safely

If you plan to use:

Solar power: Install with hybrid inverter, proper disconnects, and surge protection

Generator: Use a transfer switch to avoid backfeeding the grid

Battery system: Needs proper ventilation, fuse protection, and fireproof placement

These must be planned before finalizing your panel board layout.

8. Final Checklist Before Commissioning

Before energizing your house:

Ground test: <5 ohms preferred

Insulation resistance test for wiring

Load test of main breakers

Circuit labeling completed

All outlets polarity-checked

 Lighting and switch operation tested

Conclusion: Safe Wiring = Safe Living

Electrical work is not a place to cut corners.
With high humidity, unpredictable voltage, and sensitive equipment (like ACs or smart devices), every connection counts.

By following correct standards, hiring professionals, and using quality materials, your home will be:

Safer

More efficient

Easier to expand later

And compliant with insurance or utility inspection

Build it right. Power it safe.

Autor: Nils Deden