3504

Insulation monitoring device detected insulation error

SMA · SUNNY CENTRAL 500CP XT / 630CP XT Solar Inverter

What does 3504 mean?

The insulation monitoring device has detected an insulation error. If parameter IsoErrIgn is set to 'On', this error is ignored. This indicates a potential safety risk due to compromised insulation in the PV array.

Common Causes

  • Ground fault in the PV array.
  • Degraded insulation in PV modules or wiring.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check the PV array for ground faults using an insulation resistance tester.

Browse all codes in this manual (29)
Verified technical data. Last updated: March 2026

Related Faults

3520Insulation fault has occurred and has been fixed3507Ground fault on ungrounded terminal of PV array0205*Grid frequency change not permitted or synchronization impossible
Source: SMA SUNNY CENTRAL 500CP XT / 630CP XT Solar Inverter
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