Hi, my load values seems off.
Why is my DC load lower than the AC load?
This changes when the load is above 2kw. Then it shows more DC load than AC as I would expect because of losses.
Is my smart shunt broken?
asked
AC loads not the same as DC load
The inverter and MPPTs power values are less accurate.
You could check the SmartShunt zero current calibration to rule out that possibility (see the manual on how to do it). Especially if you clicked on the "Calibrate" button at some point.
You have both a DC side and an AC side in your system, yes? Isn't it possible to have DC loads and AC loads simultaneously that are at different levels? For example, the DC side has a load from a bunch of DC lights and a propane detector, while the AC side has a load from something plugged into an AC receptacle.
At the moment I have no DC loads. But if so, the DC side should always show more or equal than the AC side?
I'm not sure what I'm looking at in your graphic. Is it showing me that it's pulling power from the battery bank, through the inverter in the MPII and feeding an AC load...like this? I think that's what the little blue traces are showing but it's a small pic and, of course, they not animated in a screencap. :-)
If you're not putting power into the system anywhere else, then yes, these numbers do seem off. I would expect the power draw (from the battery, -153W in this case) to be greater than the output (200W to the AC side) because of inefficiency losses through the inverter. Plus, your batts discharge shows 6 amps. 25.53v x 6a = 153w, so that calculation is right. But the MPII line at the bottom says 25.52v at 9.1a. The calculations are off or the MPII getting a little extra power from someplace that's not being measured. Otherwise, you've just created a perpetual energy machine. ;-)
I do have the EXACT SAME issue and it's driving me crazy.
From one of the answers here the SmartShunt might be "broken" - how so, and how it breaks to always be like 50-80W behind?
