Parallel inverter synchronization fault

ID: fm:parallel-inverter-sync-fault
IRI: https://solarlattice.org/kb/fm/parallel-inverter-sync-fault
Status: active
Also known as: MulMasterErr, Addr-Conflict, HeartbeatLose, MasterLoseErr, SlaveLoseErr, Mode Conflict, SlavePrd-Err, MasterPrd-Err, ModeConflict, MasterSyncLose, SlaveSyncErr, Master/Slave Synchronization Message Failure, Follower Lost Fast Loop synchronization

In a system of inverters running in parallel, the master and slave units lose synchronization or cannot agree on their roles. The inverter shows alarms such as lost master or slave sync signal, an abnormal sync signal period, heartbeat loss, address conflict, multiple masters, or an on-grid/off-grid mode conflict. Common causes are a loose or wrongly connected parallel cable, a cable other than the one supplied, a cable with missing cores out of the 8, or a cable with no shield. Configuration causes include two units with the same address, a host address set to 0 (addresses must start at 1), or more than one unit set as master. Faults with the sync signal period can also come from poor local grid quality, so check the grid as well. Check the DIP switches, address settings, cable shielding and grounding, and firmware compatibility across all units. After you correct the wiring or settings, restart the inverter, and contact customer service if the fault does not clear.

<!-- review notes

sentence 6: support check: partial - The listed items are stated, but 'across all units' is not stated in the passage. -->

Claims

`caused_by`

c1 drafted · lead Unsuitable communication cable proposed

A parallel cable that is not the one supplied with the product, is missing cores of the 8-core wire, or has no shield can break communication between units.

44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r1 h=826afc04ed93
44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r2 h=88075f629793
44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r9 h=ef2d54c4c3a4

c2 drafted · lead Installation error

A loose or wrongly connected parallel signal line between inverters.

44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r1 h=826afc04ed93
44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r2 h=88075f629793
44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r6 h=cef65aa1799b
44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r9 h=ef2d54c4c3a4

c3 drafted · lead Duplicate device bus address

Two or more machines in the parallel system set to the same address raise Addr-Conflict.

44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r5 h=41aeb940851d

c4 drafted · lead Inverter parameter settings

Host address set to 0 (addresses must start at 1), or two or more units configured as master.

44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r6 h=cef65aa1799b
44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r8 h=0045ad23f8e3

c5 drafted · lead Poor grid power quality proposed

Poor local grid quality can disturb the master or slave synchronization signal period.

44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r3 h=b5096f21fbfc
44002518993-s6-hybrid-series-parallel-function-setup-guide tbl=1.r4 h=1af8e948fb46

c6 drafted · lead Communication bus wiring or termination fault

Shielding, grounding and DIP switch settings of the parallel communication link are typical checks.

44002781192-full-alarm-code-maintenance-overview sec=h11 h=ee2da61a2b27

review note: support check: partial - The passage lists DIP switch, shielded cabling and grounding as checks, but does not mention termination or tie them specifically to a bus wiring fault for sync.