Event number 4003
Event number 4003 indicates that the STP has detected a reverse current of more than 2 A on one of the string inputs. If this detected reverse current does not represent a danger for the other strings, e.g., because all strings are polarity-reversed, event number 4003 and no-load operation are generated. The DC relay is opened and the STP beeps.
The (very few) cases with event number 4003 reported to SMA Service so far all involved reverse polarity of the DC strings during a new installation, e.g., due to interchanged cables in the external DC string box or in the external DC overvoltage protection.
Corrective measures for system operators:
• Contact an installer or an SMA solar power professional. The subsequent steps require the specialist knowledge of an electrically qualified person or installer.
Corrective measures for installers:
DANGER! The tasks described below may only be performed by electrically qualified persons:
• Disconnect Sunny Tripower (see installation or service manual)
DANGER! If the STP beeps and the display shows an error message that prohibits disconnecting the ESS, wait until dark. The ESS can only be disconnected once it is dark.
• Measure the open-circuit voltages of all strings when the irradiation is sufficient, pay particular attention to polarity.
If the message keeps on appearing, even though the PV system has been checked as described, the subsequent steps must be clarified with SMA Service.
In this case, please contact SMA Service with the following information:
• Device type and serial number of the inverter
• Are there further error messages?
• How long has the error been present for now? Did it occur during the (new) installation?
• Measured DC voltages of all strings
All work on the inverter and the cabling of the PV array must be carried out by an electrically qualified person. SMA accepts no liability for the information and solutions given in the Online Service Center. Additional information can be found in our Online Service Center’s terms and conditions of use.