Introduction

Switching to solar energy is one of the best ways to reduce electricity bills and contribute to a greener planet. This blog provides a detailed step-by-step guide to installing a 3kW rooftop solar system, covering everything from planning to final commissioning.

Step 1: Planning & Site Assessment

Before installing solar panels, it is crucial to assess the rooftop space, sunlight availability, and structural integrity.

Checklist for Site Assessment:

✅ Roof Space Required: 18-20m² ✅ Orientation: South-facing (India) / North-facing (Southern Hemisphere) ✅ Tilt Angle: 15°-30° for maximum efficiency ✅ Shading Analysis: Ensure no obstacles block sunlight (e.g., trees, buildings) ✅ Structural Integrity: Check if the roof can support the panel weight

Step 2: Selecting Components

1. Solar Panels

• Model: Vikram Solar Eldora Grand 1500V
• Power Output: 315W – 340W
• Number of Panels: 9-10 panels needed for a 3kW system
• Efficiency: 16.23% – 17.52%

2. Inverter Selection

A 3kW MPPT inverter is required to convert DC from panels into AC for home use.

• Recommended Models:
  • Fronius Primo 3.0-1
  • SMA Sunny Boy 3.0
  • Growatt 3000TL-X
  • Sungrow SG3K-S

3. Mounting Structure

• Material: Galvanized Steel / Aluminum
• Types: Fixed-Tilt or Adjustable-Tilt
• Wind Resistance: 2400 Pa, Snow Load: 5400 Pa

4. Wiring & Protection Devices

• DC Cable: 4mm²-6mm² PV-rated copper cable
• AC Cable: 4mm²-6mm² copper wire
• DC Isolator: 1000V, 16A
• AC Isolator: 230V, 16A
• Surge Protection Device (SPD): For DC (600V-1500V) and AC (230V-415V)
• Earthing Kit: 6mm² copper grounding wire

5. Net Metering System

A bi-directional net meter to track energy imported/exported from the grid.

Step 3: Installation Process

1. Mounting the Solar Panels

🔹 Secure the mounting rails on the roof. 🔹 Adjust the tilt angle based on latitude (15°-30°). 🔹 Fix the solar panels using clamps. 🔹 Leave spacing to avoid shading between rows.

2. Connecting the Panels (DC Wiring)

🔹 Series or Parallel Configuration:

• Series: Higher voltage, lower current.
• Parallel: Higher current, lower voltage. 🔹 Use MC4 connectors for secure connections. 🔹 Route DC cables to the inverter.

3. Connecting to the Inverter

🔹 Connect DC output from panels to MPPT inverter. 🔹 Ensure polarity is correct to avoid damage. 🔹 Connect AC output from inverter to the AC isolator.

4. AC Wiring & Grid Connection

🔹 From AC isolator → Main Distribution Board (DB). 🔹 Install a Surge Protection Device (SPD). 🔹 Connect Net Meter → Grid Connection. 🔹 Separate circuit for home loads.

5. Earthing & Safety Measures

🔹 Connect all panels, inverter, and structure to an earthing rod. 🔹 Install a Lightning Arrestor (if required). 🔹 Ensure resistance is below 5 ohms for proper grounding.

Step 4: System Testing & Commissioning

Testing the Solar System

✅ DC Voltage Check: Measure panel output before connecting to the inverter. ✅ Inverter Configuration: Set up inverter settings (MPPT tracking, voltage range). ✅ AC Load Testing: Ensure the inverter feeds power to the home grid. ✅ Net Metering Approval: Submit for DISCOM inspection. ✅ Turn On the System: Power up DC and AC circuits.

Step 5: Monitoring & Maintenance

Monitoring the Solar System

• Inverter Apps: Fronius Solar.web, SMA Sunny Portal
• Energy Tracking: Check net metering reports
• Daily Logs: Maintain performance records

Maintenance Schedule

• Monthly: Clean panels to remove dust
• Quarterly: Check for wiring issues
• Yearly: Inspect inverter performance

Step 6: Cost Breakdown

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