Direct current (DC);
To indicate on the rating plate that the equipment is suitable for direct current
only; to identify relevant terminals.
Both direct and alternating current;
To indicate on the rating plate that the equipment is suitable for both direct and
alternating current (universal); to identify relevant terminals.
Protective earth; protective ground;
To identify any terminal which is intended for connection to an external conductor
for protection against electric shock in case of a fault, or the terminal of a
protective earth (ground) electrode.
Functional earthing;
functional grounding (US) To identify a functional earthing (grounding) terminal,
for example, of a specially designed earthing (grounding) system to avoid causing
malfunction of the equipment.
Earth; ground;
To identify an earth (ground) terminal in cases where neither the symbol 5018 nor
5019 is explicitly required.
Class II equipment;
To identify equipment meeting the safety requirements specified for Class II
equipment according to IEC 61140.
Caution;
To indicate that caution is necessary when operating the device or control close to
where the symbol is placed, or to indicate that the current situation needs operator
awareness or operator action in order to avoid undesirable consequences.
Operator’s manual; operating instructions;
To identify the location where the operator’s manual is stored or to identify
information that relates to the operating instructions. To indicate that the
operating instructions should be considered when operating the device or control
close to where the symbol is placed.
Computer network;
To identify the computer network itself or to indicate the connecting terminals of
the computer network
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