Uploaded October 2025 | Updated September 2026, 2 weeks ago
Explore the Fault Function, the core of the GFL-1500’s diagnostic capability. Learn how to inject signals on either the positive-to-ground or negative-to-ground side and choose between Array High, Array Low, or Unit modes depending on voltage and resistance levels.
This tutorial explains the logic behind each mode, including when to use manual versus automatic signal sourcing, how to read the lightning-bolt voltage indicator, and why high-capacitance arrays require special consideration.
It’s a complete guide to selecting and optimizing fault-tracing workflows for different PV configurations and resistance types.
Learn more: fluke.com/en-us/product/electrical-testing/best-solar-energy-industry-tools/fluke-gfl-1500
Explore the Fault Function, the core of the GFL-1500’s diagnostic capability. Learn how to inject signals on either the positive-to-ground or negative-to-ground side and choose between Array High, Array Low, or Unit modes depending on voltage and resistance levels.
This tutorial explains the logic behind each mode, including when to use manual versus automatic signal sourcing, how to read the lightning-bolt voltage indicator, and why high-capacitance arrays require special consideration.
It’s a complete guide to selecting and optimizing fault-tracing workflows for different PV configurations and resistance types.
Learn more: fluke.com/en-us/product/electrical-testing/best-solar-energy-industry-tools/fluke-gfl-1500
