How a Solar Farm Cut Downtime by 25% with a 1000V DC Combiner Box 1 In 1 Out Isolator

Customer Background

A mid-sized commercial solar farm in Arizona, operating a 5 MW PV installation with 2,000 panels, faced frequent maintenance shutdowns. The farm supplies power to a local grid under a 20-year PPA. Due to aging infrastructure and growing operational costs, the facility needed a more reliable and safer method to manage DC circuits.

Challenges and Pain Points

The original setup used conventional combiner boxes without integrated isolators. Each time a string needed maintenance, the entire array had to be de-energized, causing hours of downtime. Technicians also faced safety risks when working on live connections. On average, the farm lost 12 hours per month to unplanned outages., the lack of a local disconnect meant compliance with safety codes was difficult.

Why the 1000V DC Combiner Box 1 In 1 Out Isolator Type?

After evaluating several options, including boxes from manufacturers in China and Europe, the farm’s engineering team chose the Soutya 1000V DC Combiner Box 1 In 1 Out Isolator type. The key reasons were: built-in isolator switch allowing safe disconnection under load, compact 1-in-1-out design reducing wiring complexity, and full compliance with IEC 62548 and IEC 61643-11 standards. The price point was also 30% lower than comparable European products.

Implementation Process

The project was rolled out in phases over three weeks. First, a pilot installation on one sub-array of 100 kW. The team replaced four old boxes with the new Soutya units, each handling 1000V DC and up to 15 A per string. Wiring was straightforward due to the pre-wired terminal blocks. After testing isolation and SPD functionality, the entire farm was upgraded. A one-day training session helped technicians become comfortable with the local isolator operation.

Quantifiable Results

• 25% reduction in downtime – from 12 hours/month to 9 hours, due to faster isolation and maintenance.
• 30% lower maintenance costs – fewer components and easier access saved $2,500 annually.
• 100% elimination of arc-flash incidents – the isolator allowed safe lockout/tagout.
• Increased energy yield – reduced downtime added 15 MWh per year.

Client Testimonial

“The Soutya combiner box with its built-in isolator changed how we handle daily operations. We no longer need to shut down the whole site for a single string fault. It’s a simple, robust solution that paid for itself within six months.” – Lead Engineer at the solar farm

Lessons and Recommendations

• Prioritize integrated isolation: For facilities with multiple strings, boxes with per-string or per-box isolators drastically improve uptime.
• Check compliance early: Ensure the combiner box meets applicable IEC or UL standards to avoid rework.
• Plan for scalability: The 1-in-1-out modular design allows easy expansion without redesigning the entire combiner system.

Industry References

• IEC 62548:2016 – Photovoltaic (PV) arrays – Design requirements
• IEC 61643-11:2011 – Low-voltage surge protective devices – Part 11: SPDs connected to low-voltage power systems
• UL 1699B:2018 – Photovoltaic (PV) DC Arc-Fault Circuit Protection (as supplementary reference for safety)