Photovoltaic DC combiner box on-site inspection

What is a combiner box in a photovoltaic system?

In a photovoltaic system, a combiner box acts as a central hub that consolidates and manages the direct current (DC) output of multiple solar panels. Its main purpose is to simplify the wiring structure, enhance system security and simplify maintenance procedures.

How do you disconnect a PV combiner box?

Ensure the circuit breaker is in the “OFF” or “TRIP” position (or the load isolation switch is in the “OFF” position) to disconnect the combiner box from the PV DC output side. All fuse holders inside the combiner box should be open (or remove the fuse core using specialized pliers) to disconnect the DC combiner box from the PV string input side.

Why is a pre-grid connection inspection important?

Ensuring normal and stable equipment operation, pre-grid connection inspections become crucial. Excessive string voltage due to connecting too many PV panels, raising the combiner box voltage above the system’s rated voltage, can degrade internal component performance over time, leading to component breakdown or even fires.

How do I Disconnect a DC combiner box?

All fuse holders inside the combiner box should be open (or remove the fuse core using specialized pliers) to disconnect the DC combiner box from the PV string input side. Verify cable connections against the wiring diagram and internal markings of the combiner box to ensure accuracy.

Where should a combiner box be installed?

Install the combiner box in a location that is easily accessible for maintenance while protecting it from extreme weather conditions. Proper waterproofing and ventilation are essential to extend the life of the components inside the box. Regular inspection and maintenance are critical to the longevity and reliability of your combiner box.

What should I do if I accidentally contact a PV module?

Accidental contact can cause fatal electric shock or severe burns. Cover PV modules or disconnect module connectors during wiring. Ensure the circuit breaker is in the “OFF” or “TRIP” position (or the load isolation switch is in the “OFF” position) to disconnect the combiner box from the PV DC output side.