Whitened insulation is a visible change on DC cables or connectors. Damaged parts may also look melted, burned, brittle, broken or cracked. It points to a cable or connector defect, which can lead to overheating, insulation faults, ground faults, lost production and a fire risk. Scan the affected connectors and cables with an IR camera, because damaged connectors often run hot early on. Open connectors may also show corrosion. Bad cable insulation cannot always be seen, so the only sure check is an insulation resistance measurement in dry and in damp or wet conditions. Check the monitoring data for inverter low-insulation faults or shutdowns after rain or in the early morning, when damp cables are most likely to cause trips. Also compare string currents and run fault localization on isolated circuits to find the damaged run. Do not confuse whitened cable insulation with whitening on the module backsheet, which is a separate failure called backsheet chalking.
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observed_asc1 drafted · lead Hot electrical connection
Damaged DC connectors or cables, including whitened ones, often show overheating or hot spots at an early stage when checked with thermography.
tbl=45.r1 h=64afea9d2672tbl=27.r1 h=64afea9d2672c2 drafted · lead Low insulation resistance alarm
Degraded cable insulation can cause inverter low-insulation faults or switch-off, especially after rain or in the early morning when cables and connectors are damp.
tbl=28.r1 h=4c61bdc62398review note: support check: partial - Passages link degraded/damaged cables to low-insulation faults or inverter switch-off after rain or early morning, but don't tie whitened insulation specifically to it, and insulation failure isn't always visible.
presents_as c18