Module 1: Installation Standards (IEC/NEC Aligned)
Module 1: Installation Standards
Estimated time: 45 minutes | Reference: IEC 62446, NEC Article 690
1.1 System Architecture Overview
Every SolarCity installation follows a standardized architecture. Understand these components before arriving on site.
Standard System Components:
- Solar Array — LONGi panels mounted on rooftop or ground frame
- DC Wiring — 4mm or 6mm solar cable with MC4 connectors
- DC Protection — String fuses, DC isolator, surge protection
- Inverter — DC to AC conversion (Deye, Sungrow, or Huawei)
- AC Protection — AC isolator, surge protection, circuit breaker
- Battery (if applicable) — BYD HVS or Pylontech, connected to hybrid inverter
- Monitoring — WiFi/4G dongle for remote system monitoring
- Grid Connection — AC output to customer's distribution board
1.2 String Design Rules
Proper string configuration ensures the inverter operates within its MPPT voltage range.
| System Size | Panel Count | String Configuration | String Voltage |
|---|---|---|---|
| 3 kW | 6 panels | 1 string of 6 | 6 x 41.95V = 251.7V |
| 5 kW | 9 panels | 1 string of 9 | 9 x 41.95V = 377.6V |
| 10 kW | 17 panels | 2 strings (8+9) | 336V / 377.6V |
| 20 kW | 30 panels | 3 strings of 10 | 10 x 41.95V = 419.5V |
Critical Rule: Never exceed the inverter's maximum input voltage (950V for Sungrow/Huawei). At cold temperatures (-5C in northern Iraq winter), Voc increases. Maximum panels in series: FLOOR(950 / 49.9) = 19 panels. All SolarCity configurations are pre-verified — do NOT modify string design.
1.3 Mounting Standards
Rooftop Installation (most common)
- Minimum roof angle: 10 degrees (optimal: 30-35 degrees for Iraq latitude)
- Panel orientation: facing south (azimuth 180 degrees)
- Clearance from roof edge: minimum 500mm
- Spacing between rows (if multi-row): minimum 1.5x panel height to avoid shading
- All mounting points must be into structural members (not just roof sheeting)
Welding Frame vs Mechanical Rail
| Method | When to Use | Advantages |
|---|---|---|
| Welding Frame | Flat concrete roofs (most Iraqi homes) | Strongest, cheapest, permanent |
| Mechanical Rail | Metal roofs, villas, commercial | No welding needed, adjustable angle |
1.4 Electrical Wiring Standards
- DC cable: Minimum 4mm² for systems up to 10kW, 6mm² for 20kW
- MC4 connectors: Must use genuine MC4 or compatible (no mixing brands)
- Cable routing: UV-resistant conduit for exposed outdoor runs
- Grounding: All exposed metal frames bonded to earth ground
- Labeling: All DC and AC isolators clearly labeled with voltage and current ratings
Knowledge Check
Q: What is the maximum inverter input voltage for Sungrow/Huawei?
Q: What string configuration is used for a 10kW system?
Q: What is the minimum cable size for systems up to 10kW?
Answers: 950V | 2 strings of 8+9 panels | 4mm²
Rating
0
0
There are no comments for now.