Engine-room automation & monitoring

Tracing the loop before condemning the board

Fault-finding on engine-room monitoring and alarm systems starts at the loop, not the cabinet. Loops are traced end to end — sensor, wiring, module — before any board is condemned, because a control card is the most expensive part of the circuit and the least likely to have failed.

A repeating alarm with no corresponding fault is usually a sensor drifting out of calibration or a termination that has gone high-resistance. Both read as a module fault from the alarm list alone, which is why the reading is taken at the sensor and again at the input card rather than inferred from the screen.

Scope of work

Alarm & monitoring loop fault-finding

Loops traced from sensor to input card, with the reading taken at both ends rather than read off the alarm list.

PLC and I/O module replacement

Modules replaced and configured once the loop has been proven, not as a first step.

Sensor & transmitter calibration

Transmitters checked against a known reference and recalibrated where they have drifted.

Engine-room monitoring networks

Network integrity, supply and termination checked across the monitoring backbone.

Pump & compressor starter logic

Starter, interlock and control logic verified against the scheme, including auto-changeover behaviour.

As-built drawing updates

Drawings corrected to match what is actually installed, so the next engineer is not working from fiction.

Field-mounted temperature transmitter on lagged pipework in a ship's engine room, grey cast housing with digital display

Attendance sequence

Phase	Stage	Actions and deliverables
01	Measured readings	Loop readings taken at the sensor and at the input card, plus insulation and supply values per circuit.
02	Photo record	Before and after each cabinet opened or termination made, timestamped.
03	Parts & work list	Modules replaced, sensors recalibrated, logic adjusted — and what remains outstanding.
04	Recommendations	Defects found but not addressed, with a priority against the next docking, and drawings corrected to match the installation.

What is measured

A loop is proven from both ends before a module is replaced. Every reading is logged against the loop it came from.

Loop reading at the sensor

Taken at the transmitter itself, so a drifting sensor is separated from a wiring fault before anything is ordered.

Loop reading at the input card

The same loop read at the cabinet — a difference between the two ends is the wiring, not the module.

Insulation resistance

Measured on the loop wiring, which is where moisture ingress in a machinery space shows up first.

Supply and termination

Cabinet supply, common rails and termination state checked before any card is condemned.

Where this work is carried out

Vessels attended in port or at anchor across the North Adriatic, including the commercial quays at Koper.

Croatia Pula, Rovinj, Vrsar, Poreč, Umag, Novigrad

Slovenia Izola, Koper, Portorož

Italy Trieste, Muggia

Questions asked most often

An alarm repeats with no fault present — is the card failed?

Rarely. A repeating alarm with nothing behind it is usually a sensor drifting out of calibration or a termination gone high-resistance. Both look identical from the alarm list, which is why the loop is read at the sensor and again at the input card.

Can a module be replaced without the original drawings?

Yes, but the loop is traced and recorded first. Where the as-built drawings no longer match the installation they are corrected as part of the work, rather than leaving the next engineer to rediscover it.

Is calibration equipment carried aboard?

Yes — transmitters are checked against a known reference on site. Specialist tooling beyond the standing inventory is hired in where a job requires it.

Can this be done alongside a class survey?

Readings are logged per loop with a timestamped photographic record and an outstanding-defect list, which is the form a surveyor can work from.

Engine-room automation