Missing module
A module is physically absent from the racking. The gap is obvious in imagery, and the electrical consequences depend on how the remaining string was left.
Thermal signature
A rectangular gap in the array where the thermal camera reads the ground, ballast or racking behind the row instead of module glass. The surrounding modules frame the gap cleanly, and the paired RGB frame (when available) confirms the module is simply not there.
Typical ΔT
Not applicable — there is no module to measure. The frame shows background temperature through the gap, which can read markedly hotter or colder than the array.
What causes it
- Theft or vandalism
- Module removed for warranty or repair and never reinstated
- Mechanical loss — storm damage, wind uplift, racking failure
- Decommissioned module with the gap never closed out
Power impact
At minimum the missing module's output is gone. If the string was not properly jumpered when the module was removed, the entire string may be open-circuit — turning one missing panel into a string-scale loss.
Recommended action
Fix: within 30 days
Investigate within 30 days. Reconcile against maintenance and warranty records, check whether the string is still producing, secure any exposed connectors and cabling, and reinstate or jumper the position so the string operates safely.
Frequently asked questions
Is a missing module an electrical hazard?
It can be. Removal often leaves unmated DC connectors exposed to weather, and live string cabling hanging on the racking. Those connectors corrode, and a damp, corroded connector is a known arc-fault starting point — secure them promptly.
Why did the whole string stop after one module was removed?
Modules in a string are wired in series. Removing one without installing a jumper between the two open connectors breaks the circuit, so the remaining modules cannot export at all even though they are healthy.
Related anomalies
Suspect missing module on your site?
Fly the site, upload the thermal frames, and get every module graded against this taxonomy — severity-ranked, with flagged imagery and per-module locations. Quote your site size in seconds.
ΔT figures and abnormality classes on this page describe the typical industry interpretation aligned with IEC TS 62446-3 — indicative engineering guidance, not normative text from the specification. Temperature differentials are only meaningful when captured at ≥600 W/m² irradiance (per the TS) and verified on site before repair work.