L:e Voltage Slightly Higher Than L:n

[Khonwan]

My Live to Earth voltage is slightly higher than Live to Neutral by around 4V. I could understand this were N:E 4V but it’s actually 0V. What could cause this?

Rgds

Khonwan

[Crossy]

Who knows

Check outside, that Martian spacecraft perched on the 22kV could be affecting your power

Certainly not worth worrying about, but a few thoughts:-

Measurement (cheapo meter) error, 1% +- 1 digit would give a possible error approaching this magnitude on a 3 1/2 digit meter.

Voltage changed between readings.

Power factor (not sure how) but big phase angles between voltage and current can do odd things.

Different zero point on different ranges.

Weird L-E waveform confusing the meter.

Paranormal activity (your spirit house is correctly aligned isn't it).

Any combination of the above.

Do you have a MEN link?

Edited June 16, 2008 by Crossy

[Khonwan]

Who knows

Check outside, that Martian spacecraft perched on the 22kV could be affecting your power

Certainly not worth worrying about, but a few thoughts:-

Measurement (cheapo meter) error, 1% +- 1 digit would give a possible error approaching this magnitude on a 3 1/2 digit meter.

Voltage changed between readings.

Power factor (not sure how) but big phase angles between voltage and current can do odd things.

Different zero point on different ranges.

Weird L-E waveform.

Do you have a MEN link?

Hadn't thought about the Martians!

'Expensive' clamp meter. Readings taken several times. No MEN link (yet). Agreed that it's nothing alarming - just wondering as I can't make sense of it.

Thanks

Khonwan

Edit: spelling.

Edited June 16, 2008 by Khonwan

[tjo o tjim]

While Martians are the likely source, it isn't uncommon if you don't have an MEN link or if there is a break in the grounding. Just making an educated guess, I would say you are about 120m (along the wire) from the N-E bonding point.

The neutral is going to float a little higher due to the voltage drop back to the N-E bonding point. When you measure the N-E voltage, there is no current flow in that path, so no potential difference.

For the science fair project, if there is zero potential difference, you could short N and E and not have any current flow, right? To establish if there really is a problem when trouble shooting ground problems, we often short between N and E with high impedance (like a 60W incandescent light bulb). You can measure the voltage difference based on how bright the light bulb is, or use a current clamp or voltage probes. If there is no current, your ground is likely broken.