It is well known that the residual charge on live high voltage transmission line is neutralized before working hot on them.But a live low voltage line has no charge on it.It has only magnetic lines due to current flowing in it but no electric lines emanating from it i.e it is 'neutral'.Any explanation for this please?
Both low voltage and high voltage produces both an electric field and magnetic field, but low voltage systems tend to be short runs with low impedance bonding that keeps static fields from building up.
One point even if the line is not energized it can build up a static charge, while many being installed are bonded to earth to prevent this, already installed lines that have been de-energized can have a lethal static charge, some switch gear can bond the line to Earth when power is removed.
with HV you have to neutralize (bond on) to bring your body to the same level of charge that is on the line, this is because at high voltage levels air is even conductive, and static build up can also be present.
also when transferring from a boom lift or helicopter to the lines you must bring these two separate metal structures to the same potential, also the rotors of a helicopter generate static fields that must be neutralized,.
Once on the lines your metalized suit will keep you from feeling the current in the air as a Faraday cage.
there are many videos of workers bonding on to work on HV lines to do line maintenance, search U-Tube
