Page 18 - EngineerIT January 2022

MEASUREMENT

Solar installation troubleshooting

using a clamp meter

By Hans-Dieter Schuessele, application and technology expert EMEA of Fluke

he dynamic growth in solar level of protection built into a tool and how to use it when completing maintenance and
installations is creating an troubleshooting. Troubleshooting a PV system typically focuses on four parts of the system:
Tever-increasing demand the PV panels, load, inverter and combiner boxes.
for technicians who know how to
troubleshoot PV systems efficiently and 1. Troubleshooting PV panels
effectively. Clamp meters are often used A technician should first check the output of the entire system at the metering system
in the installation and commissioning or inverter. Before commencing troubleshooting, the inverter’s input voltage and
phase as well as when completing current level from the array should also be checked and recorded.
maintenance and troubleshooting. The combiner box can be a great place to troubleshoot the system because the
individual wires from the modules are brought back to it. Each module may have a fuse
The new-to-market Fluke 393 FC that should be checked with the Fluke 393 FC.
clamp meter is the world’s only CAT III Wiring problems and loose connections may cause a module to produce a voltage
1500 V rated true-RMS clamp meter that is too low. These can be traced out using the Fluke 393 FC to check wiring
which enables technicians to take connections at the junction boxes.
measurements in DC environments The Fluke 393 FC provides an audio polarity warning when testing Voc. If
such as industrial solar farms. The tool the polarity is reversed, it may mean that other circuits in the combiner box are
was tailormade to test and measure unintentionally connected in series, resulting in voltages over the maximum inverter
solar PV applications with key functions input voltage.
including:
• an IP54 rating which is ideal for 2. Troubleshooting PV loads
working outdoors on solar arrays and Start by checking the load switches, fuses, and breakers with the Fluke 393 FC to see if
wind power systems the correct voltage is present at the load’s connection. Next, check the fuses and circuit
• DC power measurement with readings breakers. Find and replace blown fuses or tripped breakers. If the load is a motor, an
displayed in kVA internal thermal breaker might be tripped or there might be an open winding in the
• an audio polarity indicator to prevent motor. For testing purposes, plug in another load and see if it operates properly.
accidental mis-wiring
• Visual continuity turns provide a
bright green light in the display to aid
technicians working in dark and noisy
environments
• Logging and reporting of test results
via Fluke Connect software

The transition to using renewable
energy is accelerating and it’s critical
that installers and maintenance staff
have access to the right instruments
to not only get solar farms online
fast, but keep them working at peak
performance.
As solar distribution systems and
loads become larger and more complex,
the implications for the safety of a
technician become more important. It is
critical for technicians to understand the

EngineerIT | January 2022 | 16