DC Combiner Boxes

DC Combiner Boxes

Designed and Manufactured in South Africa - Customized Combiner Boxes (or String Boxes)

Combiner Box with individual string current monitoring for PV power plants


• Polyester cabinet IP66
• Power supply 220V (Optional)
• Fuse-holder bases (Finger safe)
• RS485 data signal protection (optional)
• RS485 communication cables protection (Optional)
• Manual DC disconnector (digital signal optional)
• Surcharge protection (digital signal optional)
• 1000-1500V fuses
• IP66 cable glands

We give a minimum of 2 years warranty on all our products.
As electrical combiner specialists, we are able to adapt our devices to any project and customize our design to meet your technical requirements


Combiner Box Specs:
• Enclosure - glass reinforced polyester
• Fire self-extinguishing
• IP66
• Protection degree IK10 against external mechanical impacts
• Resistant to extreme temperatures: -40°C and 100 hours at +150°C
• Input and output cables through the bottom. IP66
• Busbars made from copper, appropriate to its design and dimensions.
• Opening through rigid door.
• Holes or glands sealed to prevent water leaks.
• The terminals used in the DC section withstand a voltage of a minimum of 1,500Vdc
• Provision of all necessary equipment to protect the facility and its components (cables, structures, modules, inverters, motors,etc) direct and indirect contacts, over-voltage, over-current, insulation failure protection
• GRP Cabinet has a 65% local content in South Africa



DC Combiner Boxes - Most common parts:

1. Input cable glands:
Typical cable gland input size range: up to 6mm (up to 32 inputs)
Cable gland for earth conductor

2. Outputs:
Two output cable glands suitable for up to 185mm

3. DC Disconnector:
Breaking capacity: up to 415A
Operating voltage: 1000-1500V
Auxiliary contact (optional)

4. Fuse Protection:
24 fuse protection units (positive and negative poles)
Fuse rating: 15-20A
Finger safe fuse holders

5. Lightning protection:
Class I - Class II Surge arrester for DC generation circuits (1500V, 40kA)

6. Enclosure:
Non-conductive: IP66
Material: Glass Reinforced Polyester
Color: RAL7035
Ventilation suited to prevent condensation under extreme climate conditions
Bolts,screws,washers and “mounting kit” to allow the installation of the Combiner Box to be wall mounted
Safety labels and diagrams

8. Internal Cabling:
Suited to the maximum expected operating current values
In full compliance with IEC/SANS standards
Color marking:
Positive cable: red
Negative cable: black
Grounding and bonding cables: green or yellow/green

9. Mounting kit:
Combiner box suited for fixing to a wall

10. Monitoring System:
Up to 32 monitoring channels
Hall system
RS485 communication