ABB LWT300 series User Manual

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Contents

ABB LWT300 series User Manual Manual pdf 8 page image

4 User GuideELECTROSTATIC DISCHARGESBefore performing any connection, operators shall make sure that they have dischargedall static electricity from their body before touching electronic components.• All connections must be established in a de-energized state.• Before installing the instrument, make sure that the appropriate supply voltage is available.• The power supply shall be equipped with short circuit protection and auto restart functions.• For continuous installation protection, a double insulation power supply (5 kV or higher) shall beused for the current loop.• In an industrial environment where EMIs (electromagnetic interferences) are extremely present (e.g.,rock quarries, mines, large chemical plants, etc.), ABB recommends the use of noise filters on the DCpower supply to the instrument and on signal isolators’ 4 – 20 mA output.• Instruments will not work if exposed to common mode voltages in excess of the maximum allowedsupply voltage.Grounding• Ground the instrument according to requirements (see “Grounding the instrument” on page 22).WARNINGEnsure that the equipment or any device or power cord connected to the instrumentis properly grounded.If an interruption of the protective earthing connection is suspected, make sure thatthe equipment is not used. All protective earthing connections (grounding) must beactive at all times. The absence of grounding can lead to a potential shock hazard thatcould result in serious personal injury.Use the instrument only if a properly grounded power source is available inaccordance with the local electrical code.• To avoid injury or property damage in external installations exposed to lightning, a transient voltagesuppression module or galvanic isolator shall be installed, with proper grounding, before entering abuilding with a cable. Refer to local building and electrical codes for proper practices.NOTICEThe presence of noise on the instrument 4 – 20 mA output can be a sign of poor orintermittent grounding, insufficient cable shielding, or noisy power line in the vicinity.