FI has triggered at TNS network

Check the residual current circuit breaker according to the operating instructions (TN-S units only). The RCD must be set to "I" when the MobilHybrid is switched on. Now press the "T" button. The RCD must switch to "off" (marked "O"). When the test has been completed positively, flip the switch back to "I". The MobilHybrid is ready for operation.