Alternator shunt spurious invalid current reported


  • I recently installed my first WS500 in my boat with REC-BMS and Victron integration and a dedicated alternator shunt to measure output. It\'s awesome and solved some longstanding charging issues in a fairly complex system.   However, I noticed sporadic incorrect alternator current shunt readings in my Victron VRM dashboard. Mostly, the system reported correct readings then it would pin extremely high or low for an hour at a time before fixing itself. By high: +400A / -600A. I\'ve attached a picture. I\'ve checked the connections but will re-terminate them just in case. The shunt itself looks a bit worn, so I\'m wondering if it needs a cleaning. But this could be a software issue too.   Has anyone seen this kind of thing or do you have any suggestions? Thank you for any input or ideas.


  • The first place to start is with your wiring.  The current shunt sense wire measures a very low milli-volt signal and is susceptible to outside interference.  Make sure the wires are not near or wound around any other high current conductors. Try resetting your AMP connector as well and check to make sure the wiring pins are properly seated in the connector.

  • Rick, thank you again for your helpful responses. I think you might be on to something with the induced-current idea, as the shunt sense wires are coiled near the positive power cable where a lot of current runs. Let me try cleaning up the wires and making sure they aren\'t right next to something with a bunch of power running through it.

  • Just to close the loop, I trimmed the sense wires and ran them away from high current lines. I also cleaned the contact surface of the shunt and re-terminated. No sign of this issue since. Safe to assume that the root cause was either induced currents or a bad connection of the sense wires to the shunt.

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