The solar PV system troubleshooting checklist

By SPW | April 4, 2022

By Sean Silvey, product application specialist, Fluke Corp.

As the demand for solar systems explodes across the country, so does the need for technicians who can troubleshoot PV systems efficiently and effectively.

Solar system troubleshooting typically focuses on four parts of the system: PV panels, loads, inverters and combiner boxes. Here is a checklist for locating and addressing common problems in those areas.

Being able to troubleshoot PV systems is a critical part of the professional solar technician's skillset. It's about being methodical, thorough, and using the right tools.

Before you begin troubleshooting, check the output of the entire system at the metering system or inverter, and record the inverter's input voltage and current level from the array. One of two conditions is the most likely: either the entire PV system, or a portion of it, is down or not producing power (possibly a problem with the inverter), or the PV system output is less than expected (could be an issue with one of the arrays or modules).

The PV system is used to operate electrical loads, so any problems with the loads will affect the PV system as well.

A CAT III 1,500-V clamp meter rated for the power of today's PV systems is useful for measuring DC power, AC/DC voltage and current and for troubleshooting inverters.

The inverter converts DC power coming from the solar system into AC power for use in a building or connected to the grid, and a failure there can cause problems. If the inverter isn't producing the right amount of power, it may have a blown fuse, a tripped breaker or broken wires.

Combiner boxes are a good place to troubleshoot the system.

Amperage measurements and calculations are crucial to establishing whether the PV arrays are operating correctly.

Troubleshooting PV systems efficiently is about being methodical, thorough and using tools that are rated for the job. As solar systems and loads become bigger and more complex, it's also about safety. The best all-around tool for working in most areas of a solar installation today is a CAT III 1,500-V rated AC/DC clamp meter with features — such as DC power, audio polarity, visual continuity and a thinner jaw design for tight spaces — that are tailor-made for test and measurement in solar PV applications.

Sean Silvey is a product application specialist with Fluke Corporation, a leading manufacturer of electrical test and measurement tools, including multimeters, clamp meters and insulation, and earth ground and installation testers. His focus is on application awareness, product education, and worker safety. Read more on renewable energy and solar resources from Fluke.