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A conductor within a dashed enclosing line.
Also known as: Conductor inside a screen, Dashed line round a wire, Screen symbol, Cable screen notation
The dashed line around a conductor means a screen, and where that screen is connected is the whole of the engineering: earthed at one end it stops electrostatic pickup, earthed at both it can carry a circulating current that makes the noise worse.
Denotes a screened or shielded conductor, the enclosing broken line representing the screen.
Contexts: Electrical equipment
Requires a stated screen connection to be meaningful; a screen connected at neither end provides no protection.
Contexts: Electrical equipment
Can worsen interference if earthed at both ends, where a potential difference drives a current along the screen — the earth loop problem.
Contexts: Electrical equipment
A straight conductor line enclosed by a broken or dashed line running parallel to it on both sides.