Rodent Damage — Field Documentation¶
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Rodent damage to PV wiring is one of the most common and underdiagnosed causes of solar system failures in the NYC/Tri-State market. Squirrels, mice, and rats chew through wiring insulation, creating arc faults, ground faults, and complete string failures.
Why Rodents Target Solar Wiring¶
- Panels and racking provide shelter (warmth, protection from predators)
- The underside of roof-mount arrays is an ideal rodent habitat
- Wiring insulation materials are attractive for nesting
- Once rodents establish under an array, the colony can grow significantly
Signs of Rodent Activity¶
From ground level: - Debris dropping from under the array (nesting material, droppings, food) - Squirrels or birds observed nesting under the array
From roof inspection: - Chewed wiring — look for stripped insulation, exposed conductor - Nesting material between panels and around wiring - Droppings along panel edges and racking - Damaged wire clips or conduit entries
From monitoring: - AFCI (arc fault) trips — often the first sign - GFDI (ground fault) faults - String offline or underperforming - Intermittent faults that clear and recur
Damage Assessment Protocol¶
When rodent damage is suspected or found:
- Document all visible damage with photos before touching anything
- Note: location of chewed wires, extent of damage, evidence of nesting
- Do not re-energize a system with known rodent damage until repaired
- Full array inspection required — check all accessible wiring, not just visible damage
- Escalate to lead tech — scope of repair and cost estimate required
Escalation Required¶
Do Not Repair Without Authorization
Rodent damage repairs may involve: - Full wiring replacement (not just insulation repair) - Combiner box inspection - Warranty investigation - Pest exclusion measures
Get authorization and cost approval before proceeding. Document everything.
Remediation Approaches¶
| Measure | Description |
|---|---|
| Wire repair / replacement | Replace damaged sections with rated wiring |
| MC4 connector replacement | Replace any chewed or compromised connectors |
| Wire mesh / critter guard | Install mesh along array perimeter to exclude rodents |
| Wire loom / conduit | Add conduit to protect vulnerable wiring runs |
| Pest exclusion assessment | Identify and seal entry points under the array |
Note: Critter guard (mesh skirt around the array perimeter) is the most effective long-term prevention. Recommend to client after any rodent damage finding.
Documented Cases¶
Cases to be added here from field documentation.
Visit Log¶
| Date | Site | Finding | Resolution | Tech |
|---|---|---|---|---|
| To be documented |