DDS353 and GEM120CTM

Can someone tell me in layman's terms what these two displays actually show? The installer told me, but I have now forgotten!

Philipandrea Hi, welcome to the forum.

Someone more knowledgble will probably be along later. I'd not come across these, but google finds the former as
https://www.jwsmartmeters.co.uk/shop/din-rail-mounted-meters/single-phase-din/ytl-dds353-singe-phase-meter-din-rail-mounted/
and the latter is in the givenergy knowledge base:
https://kb.givenergy.cloud/article.php?id=118&oid=19

One/both of these are fitted in the mini-consumer unit as part of your installation?
I'm guessing they will display power imported and exported by your system. Not quite sure why you need both. Ah - looks like the GEM one uses a CT clamp which is probably around your main meter feed, so it's measuring total power in and out of the house. The other, I'm guessing, measures inline power, so that's probably just the power to/from the inverter itself?

The "modbus" reference on the GEM120 means the inverter is able to access it digitally - this is its primary purpose, and is how the inverter is able to respond to changes in house load to try to keep grid import to a minimum. So the display isn't really that important for this one.

The DDS one doesn't seem to mention a modbus interface, so I'm not quite sure what that's for ???

Thanks very much for that, much appreciated. I think you are right about what they are for.

I'll be back with more questions as we can't currently connect the battery to the internet to use the app... the dongle just doesn't work and we have no internet connection at the house.

If you have no internet connection then the app won't work - even in so-called "local" mode.

That was the installer's view too

Philipandrea If you have no internet connection at the house, how did the installer commission the system?

Vestas its a requirement of the warranty that the inverters are internet connected. Sounds like the installer may have put a 3G dongle in if you don’t have home internet. If its not working they need to come back and sort it out

geoffreycoan I know but that doesn't mean it happened 🙂