N60 Voltage reference

[Energizer]

I'm in Texas, US with a normal 200a panel. 
If I wanted to monitor 40 branch circuit can you explain how and what to use for voltage reference? Is it one per each 10? or is it like iotawatt that you use just one per the whole unit.

[admin]

Is it one per each 10? --->Yes.

[Energizer]

Is it one per each 10?  --->Yes.

How do you connect the wire to the panel? You need to use special breaker or just a regular 15amp breaker will do?

[admin]

regular breaker is ok.