Quote:
Originally Posted by smac999
Measure with a clamp meter. You can zero calibration the shunt if needed. But I have install 100.’s and never had one off that needed calibration. I’d bet it’s wired wrong and you have a wire on the battery side of shunt.
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I agree with this, with an additional comment... if there were loads that were connected on the battery side of the shut the current through the shunt would be low not high. Now if the
solar panels are connected on the battery side of the shunt, there is your issue. Based on the net size of the error, I'm actually betting that's the answer, or something very similar
I recently redid a Victron
monitor that was installed by a "professional" who had no idea what he was doing, and installed it in totally the wrong place. All the
solar controllers were on the battery side of the shunt, along with the
alternator. Probably cost the
boat owner the better part of 3 grand to rewire the
boat to make it right after that yahoo go finished with it.
Totally agree that these shuts are really very accurate. There can be a very small zero offset, 10's of milliAmps) but nothing like 2 Amps. If you are seeing a consistent bias on the high side for the shunt, and you are 100% sure the
wiring was done right, the next place I would go is the connections. High resistance connections will translate into Amp readings that are higher than they should be. Anything that increases the voltage drop across the shunt will add to the error. Even things like putting the
stainless steel washers UNDER the cable terminals will cause problems. (Yes, people do this, for some odd reason...) and even a little bit of
corrosion can make a mess of things.
This should be easy to measure... which one is right? Then why is one wrong? Assuming a design fault in the shunt is very, very far down the list of possible causes.