SolarEdge Monitoring Incorrect

[PaulRLondon90]

I've got a SolarEdge System. I've googled this and find quite a lot of people talking about their CT clamps being labelled incorrectly and/or put on the wrong way.

My consumption is wildly off. For Nov11th-Dec12th the import from the grid is under-reported by almost half, according to my gas/electricity provider and smart meter I imported 1432kwh but for the same time period according to SolarEdge I only imported 414kwh from the grid, with 243kwh from battery and 278kwh from PV. The export to the grid according to my gas/elec was 44kwh but solar edge says 6kwh

I'm confused by the CT clamps. I appear to have 3?? 1 even appears link to another grey box I'm not sure what that is.

 

[Mike 134]

Why is there so much dust on them? Can you take another picture that shows the entire panel?

 

[RCinFLA]

Normal CT sensor magnetic core is somewhat non-linear so current measurement accuracy is dependent on absolute current level.

Other things effecting accuracy, in approximate order of severity on reported current error:

- Any gap in the clamp jaw effects accuracy.

- Residual magnetism of CT sensor magnetic core due to sudden surge current overload spike saturating core or being brought in close proximity of a magnet at some point in its life. If sensor max current rating is significantly exceeded during a surge current spike it will permanently magnetically bias the core effecting accuracy of readout. When core is open it is more susceptible to magnetic core bias from nearby magnetic fields. Always keep clamp closed until you need to install it.

- Temp changes on core changes reported current slightly.

Always do twisted pair on CT sensor output wires. This helps cancel any nearby stray field pickup. Twisted pair transmission line impedance is close to 100 ohms so a 100 ohm burden load resistor is often used in sense voltage receiving device.

It appears from picture that the CT sensor with black and red sense wires are not twisted together. The large black-white sensor output bundle knot of wire also should be avoided. It can corrupt the AC phasing relation sensing, important to power flow direct and power factor measurement.

 

[PaulRLondon90]

Bumping this -

I've worked out the import/export is out by 2.5x every single day. Is there somewhere in the config I can apply this in SolarEdge to correct the reported figures??

 

[Mike 134]

Bumping this -

I've worked out the import/export is out by 2.5x every single day. Is there somewhere in the config I can apply this in SolarEdge to correct the reported figures??

Yes sounds like the wrong CT size was programmed in. My Solar Edge was DIY BUT, I'm a master Electrician so was able to get all the installer info from the solar edge site as if I was an installer even though this was a one-time solar install for me. I used the "setApp" smart phone app to set the size of my CTs.

Good Luck