JLN-740MK2 JLN-741MK2

Häufige Probleme

• Transducer face fouling by marine growth or paint overspray, degrading or losing the speed signal
• Seized or stiff transducer withdrawal valve/seacock from corrosion or lack of exercise
• Speed reading drift or offset requiring recalibration
• Cable or connector faults between the transducer and the display/processor unit
• Water ingress at the transducer housing or hull gland
• Display/processor unit failure requiring unit exchange
• Loss of speed-through-water or bottom-track accuracy after nearby hull work or repainting that disturbs the transducer face

Prüfliste

• Inspect the transducer face for fouling or marine growth at each drydocking
• Exercise and check the transducer withdrawal valve/seacock for free operation
• Compare the indicated speed against GPS speed-over-ground under known current/wind conditions as a sanity check
• Check power and data cable connections and insulation condition
• Verify calibration/offset settings in the display unit against the vessel's records
• Confirm alarm and interface outputs to other navigation equipment (radar, ECDIS, VDR) are functioning
• Inspect the transducer housing and hull fitting for corrosion or leakage
• Verify the dead-reckoning/backup mode functions correctly if the speed log signal is lost

Wartungsintervalle

Typische Intervalle für diese Bauart, keine Herstellerangabe für Ihr Modell. Verbindlich ist das Handbuch des Herstellers.

Kritische Ersatzteile

• Transducer withdrawal unit seal/gasket kit
• Interconnecting cable between transducer and display/processor unit
• Display/processor unit, normally handled by unit exchange rather than field repair
• Hull fitting/seacock seal kit

Sicherheit

• The transducer withdrawal fitting is a hull penetration - incorrect withdrawal procedure risks flooding, so only trained crew should carry it out
• Withdrawal or seacock work should only be done in sea conditions and vessel status that allow the seacock to be closed safely if needed
• Electrically isolate the display/processor unit before opening it for service

Klassenbesichtigung

Speed and distance measuring equipment is checked as part of periodical safety equipment/navigation surveys; flag state and class expect the unit to be on the vessel's approved equipment list and functioning correctly, with the transducer hull fitting maintained watertight and its withdrawal mechanism operable.