WengYang Industrial Zone Yueqing Wenzhou 325000
Work Hours
Monday to Friday: 7AM - 7PM
Weekend: 10AM - 5PM
Solar PV Combiner Box Configuration Diagram
Photovoltaic Protection Box – Technical Configuration
System Overview
Product by: Kuangya Electrical Equipment Supply (cnkuangya.com)
The PV Combiner Box is a critical component in solar installations, providing centralized DC protection, monitoring, and connection management for multiple PV strings before feeding into the inverter.
Configuration Diagram
┌─────────────────────────────────────────────────────────────────────┐
│ PV COMBINER BOX (IP65 Enclosure) │
│ Model: KYDB Series │
│ www.cnkuangya.com │
├─────────────────────────────────────────────────────────────────────┤
│ │
│ ┌───────────────── INPUT SECTION (DC+/DC-) ──────────────────┐ │
│ │ │ │
│ │ String 1: [+]─┤Fuse gPV 14×85├─┤SPD├─┐ │ │
│ │ │ │ │
│ │ String 2: [+]─┤Fuse gPV 14×85├─┤SPD├─┤ │ │
│ │ │ │ │
│ │ String 3: [+]─┤Fuse gPV 14×85├─┤SPD├─┤ DC Bus (+) │ │
│ │ │ │ │
│ │ String 4: [+]─┤Fuse gPV 14×85├─┤SPD├─┤ │ │
│ │ │ │ │
│ │ String 5: [+]─┤Fuse gPV 14×85├─┤SPD├─┤ │ │
│ │ │ │ │
│ │ String 6: [+]─┤Fuse gPV 14×85├─┤SPD├─┘ │ │
│ │ │ │
│ │ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ │ │
│ │ │ │
│ │ String 1: [-]─────────────────────┐ │ │
│ │ String 2: [-]─────────────────────┤ │ │
│ │ String 3: [-]─────────────────────┤ DC Bus (-) │ │
│ │ String 4: [-]─────────────────────┤ │ │
│ │ String 5: [-]─────────────────────┤ │ │
│ │ String 6: [-]─────────────────────┘ │ │
│ │ │ │
│ └─────────────────────────────────────────────────────────────────┘ │
│ │
│ ┌──────────────── PROTECTION SECTION ─────────────────────────┐ │
│ │ │ │
│ │ DC Bus (+) ──┤DC Circuit Breaker KYDB-63├─┐ │ │
│ │ (1500V, 63A) │ │ │
│ │ │ │ │
│ │ ┌──────────────────────────────────────────┘ │ │
│ │ │ │ │
│ │ │ ┌─────────────────────────────────┐ │ │
│ │ ├────┤ DC Surge Protector (SPD) │ │ │
│ │ │ │ Type 1+2, 1500V DC │ │ │
│ │ │ │ Imax: 40kA, In: 20kA │ │ │
│ │ │ └─────────────────────────────────┘ │ │
│ │ │ │ │ │
│ │ │ ├──── PE (Ground) │ │
│ │ │ │ │
│ │ │ ┌─────────────────────────────────┐ │ │
│ │ └────┤ DC Switch Disconnector │ │ │
│ │ │ Load Break Switch │ │ │
│ │ │ Manual Operation │ │ │
│ │ └─────────────────────────────────┘ │ │
│ │ │ │ │
│ │ DC Bus (-) ───────┴────────────────────────────────────┐ │ │
│ │ │ │ │
│ └────────────────────────────────────────────────────────────────┘ │
│ │
│ ┌───────────────── OUTPUT SECTION ────────────────────────────┐ │
│ │ │ │
│ │ DC Output (+) ────────────────────→ To Inverter (+) │ │
│ │ │ │
│ │ DC Output (-) ────────────────────→ To Inverter (-) │ │
│ │ │ │
│ │ PE (Ground) ────────────────────→ Equipment Ground │ │
│ │ │ │
│ └─────────────────────────────────────────────────────────────────┘ │
│ │
│ ┌───────────────── MONITORING SECTION ────────────────────────┐ │
│ │ │ │
│ │ • Voltage Monitoring (DC+ to DC-) │ │
│ │ • Current Monitoring (per string) │ │
│ │ • Temperature Sensors │ │
│ │ • SPD Status Indicator (Red Light = Fault) │ │
│ │ • Communication Port (RS485/Modbus) │ │
│ │ │ │
│ └─────────────────────────────────────────────────────────────────┘ │
│ │
└─────────────────────────────────────────────────────────────────────┘Component Specifications
1. PV String Fuses (gPV Type)
- Model: gPV 14×85 mm
- Rating: 10A – 30A (depending on string current)
- Voltage: 1000V / 1500V DC
- Breaking Capacity: High interrupting rating for DC applications
- Function: Overcurrent protection for individual PV strings
- Features: UV-resistant, replaceable modules
2. DC Surge Protection Device (SPD)
- Type: Type 1+2 Combined
- Voltage Rating: 1500V DC
- Maximum Discharge Current (Imax): 40kA (8/20μs)
- Nominal Discharge Current (In): 20kA
- Protection Level (Up): < 4kV
- Status Indication: Visual indicator window (Red = Failure)
- Function: Lightning and surge protection
3. DC Circuit Breaker
- Model: KYDB-63 Series
- Rated Current: 16A – 63A
- Rated Voltage: 1000V / 1500V DC
- Poles: 2P (Positive and Negative)
- Breaking Capacity: 10kA – 20kA DC
- Function: Overload and short-circuit protection, manual isolation
- Features: Arc extinction technology for DC applications
4. DC Switch Disconnector
- Type: Load Break Switch
- Rating: Up to 63A, 1500V DC
- Operation: Manual rotary handle
- Function: Safe isolation for maintenance
- Features: Lockable in OFF position, visible contact gap
5. Enclosure
- Material: Powder-coated steel or UV-resistant plastic
- Protection Rating: IP65 (dust-tight, water jet protected)
- Mounting: Wall-mount or pole-mount options
- Cable Entry: Bottom entry with cable glands
- Dimensions: Customizable based on string quantity
Technical Parameters
| Parameter | Specification |
|---|---|
| Max Input Strings | 6 – 16 (customizable) |
| System Voltage | 1000V / 1500V DC |
| Max Input Current per String | 15A – 20A |
| Total Output Current | Up to 400A |
| Operating Temperature | -40°C to +70°C |
| Altitude | ≤ 2000m (standard), higher available |
| Compliance Standards | IEC 60947, IEC 61643-31, CE, RoHS |
| Warranty | 5 years standard |
Protection Features
✓ String-Level Protection
Each PV string is individually protected with gPV fuses and SPDs, preventing fault propagation between strings.
✓ Surge Protection
Type 1+2 SPD provides comprehensive protection against direct and indirect lightning strikes, as well as switching surges.
✓ Overcurrent Protection
DC circuit breakers protect the main bus and downstream equipment from overload and short-circuit conditions.
✓ Isolation Capability
Switch disconnector allows safe maintenance with visible contact separation and lockout capability.
✓ Reverse Polarity Protection
Blocking diodes or fuse coordination prevents reverse current flow during shading or module mismatch.
Installation Guidelines
- Location Selection
- Install close to PV array to minimize DC cable runs
- Ensure adequate ventilation and shade from direct sunlight
- Accessible for maintenance and inspection
- Wiring Requirements
- Use UV-resistant DC cables (PV1-F or equivalent)
- Proper cable sizing based on string current and voltage drop
- Secure cable glands to maintain IP65 rating
- Grounding
- Connect enclosure to equipotential grounding system
- Ensure SPD ground lead is as short as possible (< 0.5m)
- Use copper grounding conductors (min. 16mm²)
- Labeling
- Clear identification of each string input
- Warning labels for DC voltage hazards
- Operation instructions on enclosure door
Maintenance Schedule
| Interval | Maintenance Task |
|---|---|
| Monthly | Visual inspection of SPD status indicators |
| Quarterly | Check for loose connections, clean enclosure |
| Annually | Thermal imaging scan, torque verification |
| As Needed | Replace failed SPDs, blown fuses |
Quality Assurance
Kuangya Electrical Commitment:
- ✓ Factory acceptance testing (FAT) before shipment
- ✓ IEC, CE, RoHS compliance certification
- ✓ Rigorous thermal cycling and voltage stress tests
- ✓ Comprehensive technical documentation
- ✓ Global technical support and spare parts availability
For detailed specifications, customization, or quotation:
Kuangya Electrical Equipment Supply\
Website: cnkuangya.com\
Product Line: DC Photovoltaic Protection Systems\
Experience: 25+ years | 2000+ projects delivered worldwide
This configuration represents a standard 6-string PV combiner box. Configurations can be customized for 8, 12, 16, or more strings based on project requirements.
