Residual Current Abnormal

What does 318 mean?

A major fault indicating that the insulation resistance against ground on the input side of the SUN2000 has decreased during operation, leading to an excessively high residual current. This implies a potential ground fault or insulation breakdown, causing inverter shutdown.

• An accidental external circuit abnormality.
• The insulation resistance against ground of PV strings is too low.

Click steps to track your progress.

1. 1

   Observe if the SUN2000 automatically reverts to normal operating status if the alarm occurred accidentally due to a temporary external circuit abnormality.

2. 2

   If the alarm occurs repeatedly or persists for a long time, check whether the insulation resistance against ground of PV strings is too low.