EnEnergy calculation on M30

[WellsGoFar]

I am trying to ask good questions, but am unsure of the exact terminology to use here. Please be patient with me.

Do I need to have voltage lines in on all 3 of the M30 ports, or can I use the voltage in only one of the 3? 
Do I need to make a change in the yaml file to use voltage line 1 with energy 2_1 computation? 
For US Split Phase, does the voltage line in need to be the same circuit measured in the current lines in that bank?

[admin]

1. every 1 voltage terminal work for 10 channel current. actually M30 have 3 group detector. every 10 channel current with 1 voltage. so total 10*3 group=30 channel. if you use detect <10 channel load, it's ok only connect with one voltage terminal.

2. No, can't do that. that is fixed. voltage line 1 use for energy1_x, voltage line 2 use for energy2_x, voltage line 3 use for energy3_x

3. Yes

[WellsGoFar]

1. every 1 voltage terminal work for 10 channel current. actually M30 have 3 group detector. every 10 channel current with 1 voltage. so total 10*3 group=30 channel. if you use detect <10 channel load, it's ok only connect with one voltage terminal.

2. No, can't do that. that is fixed. voltage line 1 use for energy1_x, voltage line 2 use for energy2_x, voltage line 3 use for energy3_x

3. Yes

Thank you. 

For US Split phase 240V circuits (2 120v lines on separate phases), can I put the clamp over both lines, or do I need 2 clamps to determine if the circuit is balanced?

[admin]

use one CT sensor by any phase line is ok , not need use two CT.