Neutral and Earth detection mechanism in 3 PH electronics circuits

[Bjtpower_magic]

Hi,
I am working on 3 PH Meters configuration for North america and Europe region.(WYE Connections)
1) For north america- i understood that grid doesnt have neutral, They have Earth/GND which is connected directly to Enclosure body. (All Phase measurement done wrt to Earth)
2) For Europe region- We have 5 wire system (L1, L2, L3, N and PE)- Where all measurment done wrt to Neutral (Correct if i am wrong)

Problem statement is- I want to involve circuitry which will detect when External neutral wire is absent and same for Earth/GND Connection.

How can we detect that Neutral or PE Cable is not connected so accordingly we can take action thru controllers?

Please help out with few articles or application note or Idea.

 

[d123]

Hi,

Do they have identifiably different habitual impedance values/ranges that could be used to select one measurement circuit configuration or the other?

 

[FvM]

In a grid without neutral, you have load only connected between phase terminals. Phase-to-ground voltage is respectively irrelevant. What do you exactly want to achieve?

We have in Europe also 4-wire connection (3 phases + PE) of high power systems in industry. They are internally generating 230 V control voltage by a 400/230V transformer. You don't perform measurements between phase and PE in these systems and make no assumptions about the potential of a virtual star point.

 

[scopeprobe]

Hi,
I am working on 3 PH Meters configuration for North america and Europe region.(WYE Connections)
1) For north america- i understood that grid doesnt have neutral, They have Earth/GND which is connected directly to Enclosure body. (All Phase measurement done wrt to Earth)
2) For Europe region- We have 5 wire system (L1, L2, L3, N and PE)- Where all measurment done wrt to Neutral (Correct if i am wrong)

Problem statement is- I want to involve circuitry which will detect when External neutral wire is absent and same for Earth/GND Connection.

How can we detect that Neutral or PE Cable is not connected so accordingly we can take action thru controllers?

Please help out with few articles or application note or Idea.

You could look at passing L1, L2, L3 & N through a magnetic core. The field of the Live currents should be cancelled out by the Neutral return current in normal circumstances. A seperate reference winding on the core would generated a voltage when the return current doesn't cancel out which could be detected by a an comparator or processor.