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Events 77, 7701, 7702 or 7703 | Knowledge | Salesforce

Event numbers 77, 7701, 7702 and 7703 indicate a problem related to the relay test.

Before connecting to the grid, the inverter checks the grid relays and monitors the grid quality. Only if all test results are positive, the relays are switched and the inverter connects to the grid.

For all 3-phase inverters (STP): Especially in new installations, (but also in existing installations, depending on the grid quality on site)  the error often appears in connection with a shifted neutral point / star point. This can be caused by larger consumers on the grid, for example air conditioners, pumps, large motors and lifts or by a faulty installation.

Therefore, it is advisable to check the installation with regard to the correct connection of neutral conductor and PE (grounding), not only at the inverter connection but also in the sub-distribution and main distribution, and - depending on the plant size and system configuration - possibly also on the grid / plant transformer.

Corrective Measure:
Please contact your installer for further investigation.

Solar Power Professional

Additional information for Solar Power Professionals:

Special cases:
For all Sunny Boy (SB) inverters and for the Sunny Tripower (STP) of the type STP 20000TLEE-10, STP 20000TL-30, STP 24000TLUS-10, STPxx000TL-10 and STP xx000TLEE-JP-10/11: 
Please clarify the corrective action with the SMA Service before you check the AC installation.

Corrective Measure:

If the message keeps on appearing, clarify the issue with SMA Service, providing the following information:

Service Partner

Internal

Solution

The cause can be:

Defect AC Relais

  1. Single-phase inverters:
    For small or single-phase inverters, the error is usually (not always, but usually) permanent and the inverter or AC-CON must then be replaced.
    The cause is simply due to defective relays or the defective control of the relays.
  2. !Confidential Information! 
    Bluenote 620: AC Grid Relay Error 7702 and others
    Affected:

Overview of the AC-CON boards, which are already equipped with other relays, see this article: AC-CON Boards with New Relais - Supplement to Bluenote 620
For all STP with affected hardware: If it is not a new installation, and the error is permanent, we will replace the inverter or AC-CON component. In this case, the customer does not necessarily have to check the installation.
Please note: If, according to Bluenote 620 [link], preventive measures are carried out on a system, please also observe Bluenote 668 [link].

  1. ​Confidential Information
    Bluenote 668: Titan AC-IGBTs died due to overheating
    Affected:

In the case of a defect in the semiconductor module, as a consequence, the relay can also be destroyed. STP 20000TLEE-10 with affected assemblies need a component or inverter exchange. PCB-assembly change in field is preferred.

  1. For all other STP and for all STP in new installations, a fault in the AC installation is more likely than an inverter defect. Please check thoroughly.

Fault in AC Installation

Ask for the installation date: in new installations, a fault in the AC installation is more likely than an inverter defect.​

In new installations (but also depending on the power quality on site), the error often appears in connection with a shifted neutral point (star point).
This can be caused

Therefore, it is advisable to check the installation with regard to the correct connection of neutral conductor and PE.
This check should be carried out by measurement and visual and mechanical inspection.

Measure:

Voltage peaks / AC overvoltages can lead to defect of the AC relays.
Pay special attention and consult RSE / expierenced colleague, if there are several inverters with this problem in the plant, or if the previous inverter had an AC-related error, too.

If the fault persists even after a reboot of the inverter and the grid quality (voltages L to N, L to PE, N to PE and L to L) is okay, you can assume a defect in the AC relay. replace inverter or AC-CON component.

Further information

The following messages might be displayed in this context:"Event number 6404", "Event number 6408", "Event number 6411", "Event number 6432".

Observe the following diagnosis, if applicable:
"STP-TLEE (JP) - CRM Service ticket creation for assembly replacement (ACCON)".

Events 77, 7701, 7702 and 7703 in combination with Events 64, 6404, 6407, 6438, 64XX or 3501

Grid Relays contacts can stick together (bonded contacts) or can be destroyed by high currents that are caused by ground faults during operation.
The DC side should be checked for ground faults.

How to check the DC - Side see article: Event 35 or 3501

Special case STPxx000TL-30 displayed event 7702 (inicially) and after ACCON replacement showing event 6304:
In this case most probably the AST board was also damaged but the defect was hidden by the inicially reported relay defect. If the event can not be cleared by a reboot of the inverter a replacement of the AST board can solve the issue.

Documents

Developers Information and Wording for Event 77: see Excel Sheet "Eventliste"

Information:
The attachment contains the text which is sent to the customer/installer via Smart Connected in the event of an error.![[20082020_Event 7702_EN.pdf]]