Question about strange observation

[CallumWK]

I previously had the issue that the safety cut in the house, which protects the circuit that leads to the maids quarters, would sometimes suddenly trip.

 

I have been working on it and assume it has been sorted.

Though while working on it I had a strange observation.

With all breakers in the maids quarter open, including the main breaker, and all wall switches open.

With a multimeter I measure 235V between incoming positive and all red wires, as well as between incoming positive and the neutral bus bar and the grounding bus bar.

Is this normal?

[impulse]

15 minutes ago, CallumWK said:

I previously had the issue that the safety cut in the house, which protects the circuit that leads to the maids quarters, would sometimes suddenly trip.

 

I have been working on it and assume it has been sorted.

Though while working on it I had a strange observation.

With all breakers in the maids quarter open, including the main breaker, and all wall switches open.

With a multimeter I measure 235V between incoming positive and all red wires, as well as between incoming positive and the neutral bus bar and the grounding bus bar.

Is this normal?

 

You may want to include a photo inside the circuit breaker box so there's no confusion between wire colors and what is connected to what. 

 

Also, by "open", do you mean turned on or turned off?  I'd interpret that to mean disconnected, but some folks would interpret that like an open faucet, meaning turned on and flowing.

 

[Crossy]

You are probably reading "phantom voltages" caused by capacitive coupling and the high input-impedance of your multimeter.

 

Also, any load still on those circuits (plugged in charger for example) will have a similar effect.

 

Nothing to worry about.

 

 

 

 

[CallumWK]

17 minutes ago, Crossy said:

You are probably reading "phantom voltages" caused by capacitive coupling and the high input-impedance of your multimeter.

 

Also, any load still on those circuits (plugged in charger for example) will have a similar effect.

 

Nothing to worry about.

 

 

 

 

 

Phantom voltages are ghost voltage, so i assume they would be much lower than 235V and would disappear as soon as you connect anything?

 

Nothing plugged in the wall sockets either.

 

To be clear I measure between the marked wire and any red wire - neutral bar - grounding bar

 

 

 

[Crossy]

The magnitude of phantom (or whatever you want to call them) voltage is very much dependent upon your wiring arrangements and the length of parallel runs. it's this effect that sometimes causes LEDs to "glow" even when off (most annoying that is).

 

"Electricians meters" often have a "low-impedance" button that slugs the input of the meter to bust the ghosts. 

 

You could try a small 220V incandescent lamp instead of your meter, if it lights you have a problem.

 

Do you read anything between neutral and your "off" circuits?

[CallumWK]

2 minutes ago, Crossy said:

Do you read anything between neutral and your "off" circuits?

 

No readings

[Crossy]

Just now, CallumWK said:

No readings

 

You mean "zero" volts, yes?

[CallumWK]

Just now, Crossy said:

 

You mean "zero" volts, yes?

 

Yes zero volt

[Crossy]

I think it's absolutely fine, but do try a lamp if you have one 🙂 

 

[CallumWK]

26 minutes ago, Crossy said:

I think it's absolutely fine, but do try a lamp if you have one 🙂 

 

 

Did just that, incoming hot to red wires negative - Hot to neutral bar negative - hot to ground bar safety cut trips

 

[Crossy]

 

Grounding the hot (via your lamp) should be tripping the Safe-T-Cut - it did 🙂 

 

If your lamp never actually lit, (maybe a flash hot to ground before the Safe-T-cut opened) there's really no issue.

 

What are you actually worried about?

 

 

 

[CallumWK]

3 minutes ago, Crossy said:

What are you actually worried about?

 

I was worried that the measurements I noticed were abnormal, but seems to be fine then. Thanks

 

Lamp didn't lit when connecting to ground bar, safety cut tripped instantly.

 

I had a short flash one time connecting hot to the red wire that goes to the waterheater, but after that it was negative.