• Avoid using wired telephones during an electrical storm. There is a remote risk of electric shock fromlightning.• Do not use a telephone in the vicinity of a gas leak to report the leak.• Rack Mount Instructions—The following or similar rack-mount instructions are included with theinstallation instructions:a. Elevated Operating Ambient—If installed in a closed or multi-unit rack assembly, the operating ambienttemperature of the rack environment may be greater than room ambient. Therefore, considerationshould be given to installing the equipment in an environment compatible with the maximum ambienttemperature (Tma) specified by the manufacturer.b. Reliable Earthing—Reliable earthing of rack-mounted equipment should be maintained. Particularattention should be given to supply connections other than direct connections to the branch circuit(e.g., use of power strips).SAVE THESE INSTRUCTIONS1.1.3 PrecautionsGeneral information• In the event of problems, you should contact your equipment supplier in the first instance.Graphical symbols for use on equipment and their descriptionsSymbol Explanation Symbol ExplanationAlternating current (A.C.)Class Ⅱ equipment (equipment inwhich protection against electricshock relies on Double Insulation orReinforced Insulation)Direct current (D.C.) "ON" (power)Protective earth "OFF" (power)Protective bonding earth Stand-by (power)Functional earth "ON"/"OFF" (power; push-push)For indoor use only Caution, risk of electric shock1.1.3 PrecautionsOperating Manual 11