G
Graysonlad
I have been following a thread on another forum in which a guy reported that the neutral bar on a fused board was at times "glowing hot" At other times, when a neutral was disconnected there was a spark. This was on a 240 volt single phase AC supply. He also reported that when measuring voltage across neutral to earth he got a reading of 130 volts.
This intrigues as I have never come across this before. I have had three phase motors and three phase battery chargers burn out due to a phase having gone down on a three phase supply, but never this.
With regards to disconnecting the neutral, my own working rule is never disconnect a neutral whilst it is carrying current. I wonder if that could be the reason for the sparking i.e. it was in use?
Q 1: Would a bad connection on the earth or neutral be the cause of the 130 volts on neutral to earth?
Q 2: Testing across neutral to earth, on a sound/good installation, what voltage reading would you expect?
Q 3: Metering between Live and Earth what value would you expect?
Note: Having checked the single phase supply at my home I get approx 30 volts at:
Neutral -Earth. and the same again at Line - Earth.
Line to Neutral reads 240 Volts.
This intrigues as I have never come across this before. I have had three phase motors and three phase battery chargers burn out due to a phase having gone down on a three phase supply, but never this.
With regards to disconnecting the neutral, my own working rule is never disconnect a neutral whilst it is carrying current. I wonder if that could be the reason for the sparking i.e. it was in use?
Q 1: Would a bad connection on the earth or neutral be the cause of the 130 volts on neutral to earth?
Q 2: Testing across neutral to earth, on a sound/good installation, what voltage reading would you expect?
Q 3: Metering between Live and Earth what value would you expect?
Note: Having checked the single phase supply at my home I get approx 30 volts at:
Neutral -Earth. and the same again at Line - Earth.
Line to Neutral reads 240 Volts.