I think I must be missing something obvious, but I’m trying to setup EmonPi2 on a 3-phase supply
I have 3x100A CT clamps on the 3 supply phases.
On the default single phase firmware it came with I get readings of:
P1: 1394, P2: -394, P3: 175
If I change to the 3-phase firmware I get:
P1: 1425, P2: 0, P3: 0
I’m using a single phase emonVS, does this have to be a 3-phase version for it to work with P2 and P3 correctly? I’m just after a total value that tracks the billable amount on the meter.
(From the previous monitor it’s replacing the phases weren’t well balanced with most usage on phase 1)
Yes, to use the three-phase firmware to monitor three-phase it’s essential to use a three-phase emonVS which is connected to each phase to be able to get voltage sample of each phase:
It would be possible to use a single-phase emonVS and single-phase firmware to monitor one of the phases, you will need to make sure the emonVS is connected to the same phase as the circuit your monitoring.
Is it possible to use the other 3 CT clamps (4, 5 and 6) to monitor single phase feeds to individual devices, or are they tied to the same 3 phase setup?
e.g So you could use CT1-3 to monitor a three-phase incoming supply then use CT 4-6 to monitor single phase loads, but CT4 can only monitor a single phase load on L1, likewise CT5 can only monitor a load on L2.
It is possible to adjust these allocations, but this will require recompiling the firmware.
Indeed. If you’re able to edit, recompile and reload the sketch, you have complete flexibility in which voltage(s) each CT is paired with. If you want and feel competent to do this, the emonLibDB documentation gives full details.