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Smartshut DC Energy Monitor for Hydro Generator showing negative power

I have a 100% Victron System with a hydro generator and 3 separate solar arrays. Our Hydro is running through a VIctron MPPT Charge Controller to help give us a little more boost from the hydro. I also hae a smartshunt (configured as a DC Energy Meter) installed between the Hydro MPPT and the battery buss to monitor the power our hydro is feeding into the batteries. Everything is working well except the current coming into the MPPT controller is positive and the output power is showing negative for the hydro. We have checked all of the wiring and it is proper. Does anyone have any idea what might be causing this?

MPPT SmartSolarSmartShuntHydro and Wind Power
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seb71 avatar image seb71 commented ·

Everything is working well except the current coming into the MPPT controller is positive and the output power is showing negative for the hydro.

Not clear what you meant to say here.

Anyway, it sounds like the SmartShunt is mounted in the wrong direction (In/Out).

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mtsguy answered ·

The Shunt is wired correctly. In fact we even temporarily reversed the wiring to check it and there was no change. The postive to negative change seems to be happening in the MPPT Charge Controller and not the smartshunt. The readings from the hydro into the MPPT are positive on the PV input side and negative on the battery side.

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seb71 answered ·

Victron MPPTs are designed for PV panels, not for hydro.

Could be damaged.

But post some screenshots with those "negative readings".

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mtsguy answered ·

20230823-103118.jpg

This shows the input to the MPPT from the hydro as positive current.

20230823-103132.jpg

This is the MPPT output as showing as negative current. This output goes directly to a smartshut then to the battery buss.

screenshot-20230823-103216.jpg

This is a screenshot of the MPPT.

All wiring has been checked and rechecked and is correct.


20230823-103118.jpg (225.8 KiB)
20230823-103132.jpg (229.2 KiB)
screenshot-20230823-103216.jpg (167.2 KiB)
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seb71 avatar image seb71 commented ·
Current flow is normal.

MPPT screenshot looks normal.


How is the SmartShunt wired?


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seb71 answered ·

The Shunt is wired correctly. In fact we even temporarily reversed the wiring to check it and there was no change.

This is hard to belive.

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mtsguy answered ·

The battery output of the MPPT goes into the source side of the shunt and the other terminal is connected directly to the battery buss.

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seb71 avatar image seb71 commented ·

By "Source side" you mean the side labeled "To system minus", I presume. That looks correct (if it is in the negative wire).


But you say that reversing the Shunt does not reverse the Shunt reading (+/- flow direction of current and power as shown by the SmartShunt)?

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mtsguy answered ·

Reversing the shunt does not change the reading.


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