ADE7953 single phase connection for Dual live wire

there are a couple ways to do this 

1.  measure line to line voltage and current in each leg.    after calibration    power line 1 = voltage/2 * IA   power line 2 = voltage/2 * IB

2. measure line to line voltage and use one ct to measure both line 1 and line 2 currents. The link below explains this method

https://www.analog.com/media/en/technical-documentation/application-notes/an564.pdf   

3. If you need all voltages and currents use a 3 phase part only connecting 2 phases. 

Dave 

Dear Dave

       Some questions as below. Could you help it? 

1.  for CNS connection , is it correct for Fig 1? 

2. For UL connection, N phase is replaced by L2. Has any problem for it?  If not use the same board for UL and CNS, how  to design for CNS & UL board? 

3,  if connection is for differential, is it ok also for Fig 3? Thank you. 

Fig 1

Fig 2

Fig 3

BR

Patrick

Figure 1 and 2 are basically the same which are correct implementations just exchanging neutral for L2 . when usign figure 1 you have to assume Line and neutral may be swapped at installation the GND may be live even in figure 1. figure 2 gnd will be Live(L2 to earth)

3. What is the purpose of figure 3? Is this for protective impedance ? As far a voltage measurement it is similar to figure 1 and 2.  

Dave

Hello Dave

   Per my understanding, if figure 1 and figure 2 maybe have Live to earth while Line and neutral swapped. The GND of ADE7953 is connected to neutral but nor connect to earth, right? Or have any standard connection compatible CNS & UL to suggest? 

Other questions: 

1. The current of neutral must be measured by CT? Or just only measure L phase current is enough. 

2. If we not measure the current of  neutral . Could IBP、IBN be used for leakage current measurement? 

3. If we would like IBP、IBN for  leakage current measurement,  have any sample code or scenario to implement this function? Thank you.

BR

Patrick

Hello Dave

        Could you help comment as above? Thank you. 

BR

Patrick

Hello Dave

        Could you help comment as above? Thank you. 

BR

Patrick

   Per my understanding, if figure 1 and figure 2 maybe have Live to earth while Line and neutral swapped. The GND of ADE7953 is connected to neutral but nor connect to earth, right? Or have any standard connection compatible CNS & UL to suggest?  Isolation may be required to meet UL and CNS safety requirements 

Other questions: 

1. The current of neutral must be measured by CT? Or just only measure L phase current is enough. If this is single phase  not split  with line and neutral only one CT is needed 

2. If we not measure the current of  neutral . Could IBP、IBN be used for leakage current measurement? You could try, phase b current will give you RMS of anything you put into the inputs. Size the ct and burden appropreately. How fast do you need to respond to the leakage that may be the issue. 

3. If we would like IBP、IBN for  leakage current measurement,  have any sample code or scenario to implement this function? Thank you. This is just an RMS measurement  or you may need to use waveform samples. I do not have code for this 

Dave