Neutral to Earth voltage in 3 Phase

[Bjtpower_magic]

Hello Everyone,
Hope you are doing well and Safe!

I have small observation for 3 Phase system.
First observation-
1) When 3 Phase AC Source was balanced
a) L1-N=230VAC
b) L2-N=230VAC
c) L3-N=230VAC
i checked voltage between Neutral and PE (Protective Earth) and found it 0.023V

Next observation-
1) When 3 Phase AC Source was imbalanced
a) L1-N=230VAC
b) L2-N=230VAC
c) L3-N=0VAC
i checked voltage between Neutral and PE (Protective Earth) and found it 70V

Now i could not able to differentiate why this is happened.
Can someone help me with mathematical calculations how to find Neutral to PE (Protective Earth)?

Marx

 

[KlausST]

Hi,

L3 - N = 0V sounds like a short circuit ... or an open L3

Please show how the load is connected in "imbalanced state". Which load from which point to which point?

Klaus

 

[betwixt]

It is impossible to calculate. As Klaus pointed out, the measurement depends on the exact circuit details. In theory, PE and Neutral are different circuits so any potential is possible.

If PE and Neutral were joined together, which is a common scenario, there would always be zero between them, excepting some small amount due to wire resistance, inductance and capacitive coupling.

Brian.

 

[Easy peasy]

If the neutral and earth wiring are too small, or the N-E linking bar at the nearest distribution board is faulty

you will get readings like this - what country / city are we talking about ? possibly not a 1st world one ?

Also what are you measuring with ?