Gary started another thread for EKM metring, but I will answer your question here in case you don't see the new thread. The meter needs voltage inputs and current inputs that can be obtained directly from the line side of the EVSE (at the EVSE or junction box). Small donut-shaped current transformers around the supply conductors provide the current inputs. Voltage inputs come from connections to the line side conductors also. The voltage inputs should be fused with 1 ampere inline fuses to protect the meter and the small wires going to it. The meter is powered from the voltage inputs so it does not need a separate low-voltage power supply but it will need the neutral conductor in addition to ground and line conductors. I have been using a couple of EKM meters to monitor my Leaf power consumption and the power usage at my workshop garage for several months, but have not yet tried data logging. I will be looking at the thread Gary started for tips on the software and RS-485 connections.waidy said:Dear GaryGID. Thanks for the product recommandation and it saves me a lot of reading time. This is really good information. The photo has a pair of what it looks like a low voltage power wires. The installation instruction does not say it needs to be connected. Do you know by any chance whether the $140 EKM-25IDS-N unit needs to be connected to a low voltage power source? Is there a power pin inside the OpenEVSE I can tab the $140 meter. My electrician is coming tomorrow so it's a good time to add if the lower voltage is needed.
Gerry