Internal fault (e.g. residual current monitoring unit)

What does 715 mean?

The Fronius Primo GEN24 208-240 inverter has detected an internal fault within its residual current monitoring unit (RCMU). This unit is crucial for detecting ground faults and ensuring safety. A fault here means the inverter cannot safely operate and will shut down.

• Internal fault (e.g. residual current monitoring unit).

Click steps to track your progress.

1. 1

   Perform a full power cycle of the Fronius Primo GEN24 208-240 inverter by opening both the AC circuit breaker and the DC disconnector, waiting, and then reclosing them.

2. 2

   Ensure there are no actual ground faults in either the AC or DC circuits that might be causing the RCMU to incorrectly trip or fail.

3. 3

   Check for any moisture ingress or contamination within the inverter that could affect sensitive RCMU components.

4. 4

   Review the inverter's event log for any preceding fault codes related to insulation faults (e.g., 3xx codes) or grid issues.

5. 5

   As this is a critical safety component, if the fault persists, contact Fronius service immediately for inspection and potential replacement of the RCMU.