Even more weird, is i have been searching the manual for AC coupling, but the manual sucks, and I have not found anything in the GUI or the manual. I am hoping Ian from Watts247.com puts out a video on the functions.
I am not sure if the way they use the term "AC Coupling" is the normal technical meaning. They seem to have an internal relay on the AC side (manual does not explain it though) for input and output functions, based on the grid tie level used programatically. It does test the input frequency and voltage levels though, as there are error codes when they are out of spec. I need to do a lot of testing once my units arrive.I searched it too (in both manual) and did not found anything related to this function
But for the US model there is even a pic in the the MPP Solar site about AC coupling (not in the EU model):
Thanks! You found it for me! Its mode 36 and 38! This will be fun to test....The Pic shows a normal AC coupled system
Deye/Sol-ark can do it. It would be great if MPP Solar can do it too.
So the differences in the menu:
Only EU version has:
35 - N/G relay close in battery mode
Only US version has:
36 - External CT function Disable (default) Enable
37 - PV parallel Disable(default) Enable
38 - Ac output coupling
Seems like that energy meter should allow the inverter (when in grid tie mode) to zero the grid usage. I’d really like to see more info regarding the modbus card and how that all works. I’ve heard of inverters using an energy meter to do limiting to grid. The SolArk and the GTIL2s (and manyother inverters) only use Cts, no external energy meter needed.
Where are you seeing 36 external Ct function? Found it nvm. I was looking at the UK manualI searched it too (in both manual) and found this function only in US model:
38 - Ac output coupling
But for the US model there is even a pic in the the MPP Solar site about AC coupling (not in the EU model):
More weirdness ...
US model has:
36 External CT function
EU model does not have this menu point.
But it has a pic with the Energy Meter and RS-485 connection.
We will need 3 people to lift it to the wall ?
Any idea how much the energy meter sells for?CT's are really clamp meters.
They measure the Amps flowing through and give out a DC Volt. This (analog) Volt is measured on the other side, this is how it knows the current Amps flowing and its direction.
You have two + and - because you use split phase and have 2 CT's
So here the CT's Volt is converted into Amp values in the inverter
An energy meter is an outside converting an communication unit.
The same DC Volt comes in from the CT's and it converts them to Amp values.
But it also communicates this values into the inverter (digitally like RS485).
So it is better sometimes because you can have a longer distance between the inverter and the CT sensors.
(digital signal can travel higher distances while analog signal could be corrupted)
The 2 big white box in it are relays
DPDT - Dual pole dual throw relays to be exact.
Why double throw (like a transfer switch)? I do not know :D
Does that energy meter have Cts inside of it, or do I need to also purchase Cts? I think I read in the manual that the inverter comes with an internal modbus card.
Do the grids wires have to go thru it? If Cts aren’t needed then what is the EX CT positive and negative ports for?
I’m in the US. The manual doesn’t talk at all (that I seen) about limiting the inverters output by using the Cts.That is for the US version
The EU version uses Energy meter (with inner CT and RS485 communication to inverter).
The US version uses external CT's and direct cables to inverter.
This is maybe the only part where EU version is a bit better.
