in our installations we use Eastron SDM 630 meters as grid, production as well as consumption meters.
We have installed them according to the manufacturers wiring diagrams where “incoming” energy e.g from grid/production flows from top of the meter through into the EMS being a the bottom of the meter. While on the other hand side the energy from EMS at the top of the consumption meter is flowing down to the consumer which is connected at the bottom of the meter.
At first we used the already existent Microcare SDM 630 meter component in OpenEMS. The Microcare is constructed identical to the Eastron afaik.
But we noticed that the energy readings where going in the wrong direction; consumption instead of production an vice versa.
In other meters we have seen an “inverted” flag which sometimes inverts only energy (which would help) but sometimes also inverts power and current.
Sometimes there could also be a “wrong” wiring in the installation like where a consumer is connected to the top of the meter. To avoid further confusion, we think the existing inversion functionalities should be restricted to this case only.
After further studies and discussion we came to the conclusion that the energy channel assignments should be generally “inverted” only based on the meter type.
For better demonstration and discussion we created this overview diagram:
Additionally, to demonstrate this in code we created this PR: Switch energy assignment and power inversion based on the meter type. by phfeustel · Pull Request #2176 · OpenEMS/openems · GitHub
My question to the community are:
- Does the switch of energy, power and current channel assignments based on the meter type make sense?
- Is a “wiring direction reversed” flag helpful to “fix” wrongly installed meters? If yes, should we move this functionality to a higher level like the AsymmetricMeter/SymmetricMeter or the new ElectricityMeter?
- If 1. and 2. are correct, should all meters be adapted to a common standard to avoid feature confusion?