Mn1600

Common issues

• Reading drift or offset developing over time on the sensing element
• Cable or connector corrosion at the terminal/junction box
• Loose or degraded surface mounting giving a falsely low reading due to poor thermal contact
• Moisture ingress at the cable gland leading to intermittent or erratic signals
• Physical damage to the sensing element from mechanical impact or vibration
• Intermittent signal from oxidised or loose connector contacts

Inspection checklist

• Compare the sensor's reading against a calibrated reference thermometer at the same point
• Check the mounting clamp/bracket for tightness and good thermal contact with the monitored surface
• Inspect the cable and gland for damage or signs of moisture ingress
• Check the terminal/junction box for corrosion
• Verify alarm and trip setpoints in the alarm monitoring system against the class-approved list
• Check cable routing for chafing or heat damage along its run
• Confirm the sensor's tag/loop identity matches the alarm system database
• Verify loop power supply/signal voltage is within specification

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Complete replacement sensor unit (these are normally exchanged as a unit rather than repaired)
• Cable gland and connector kit
• Mounting bracket/clamp
• Terminal block/junction box hardware
• Marine-grade signal cable for the run length in use

Safety

• These sensors are frequently mounted on hot surfaces such as exhaust piping or bearings - burn hazard during replacement
• Electrically isolate the loop before disconnecting, especially on energised or hazardous-area circuits
• A miscalibrated sensor on a safety-related loop can trigger a false trip or, worse, mask a genuine alarm condition

Class survey

These sensors form part of the vessel's approved alarm monitoring system; class will normally expect the alarm/trip list, including setpoints for each sensor loop, to be verifiable at survey, and any replacement sensor to be like-for-like or otherwise re-approved with the system supplier.