Electro-Technical Officer (ETO) interview questions

The earth fault monitor or insulation monitor on the switchboard shows that the insulation resistance on a system has dropped. On an insulated (unearthed) system, one earth fault does not stop the equipment, but a second fault on another phase can cause a short circuit, so I find it quickly.

My method:

1. Identify the affected system and switchboard section from the monitor.
2. Isolate circuits one by one, in agreement with the engineer on watch and, for essential consumers, with the bridge, and watch the monitor. When the reading returns to normal, I have found the faulty circuit.
3. Test the circuit with an insulation resistance tester (megger) after isolating it, and narrow down to the cable or the consumer.
4. Repair the cause, often water in a junction box, a damaged cable or a faulty motor winding, and test again before putting it back in service.

I record the readings and the repair, because regular insulation readings help find a deteriorating circuit before it fails.

High-voltage work is done only under a permit to work and the company's HV safety procedure, by authorised persons. The key steps are:

1. Planning and permit: the job, the switching plan and the isolation points are agreed with the Chief Engineer, and the permit is issued.
2. Isolation: the equipment is disconnected from every possible source, including back-feeds, and the breakers are racked out, locked and tagged.
3. Test for dead: I prove the voltage tester on a known source, test the equipment, and prove the tester again.
4. Earthing: the conductors are earthed with the approved earthing switch or portable earths before work starts.
5. Safety barriers and signs around the work area, and only authorised people inside.

The permit is cancelled only after all the people and tools are clear, the earths are removed and the equipment has been checked. I never work alone on HV equipment.

I start by understanding the fault: what the alarm says, when it happened, and what the operator saw. Then I work from the outside in:

1. Check the basics: power supply, fuses, communication cables and connectors.
2. Check the field devices: sensors and transmitters give the right signal (for example 4–20 mA), actuators respond, and wiring is not damaged.
3. Check the PLC: the status lights, the diagnostic messages, and the input and output states compared with the real condition.
4. Use the drawings and manuals to follow the signal path; I do not change settings or software without the Chief Engineer's approval and a backup.

After repair I test the function with the operator and record the fault, the cause and the solution. Many repeated faults come from the same weak point, such as a vibrating connector or a damp junction box, so I look for the root cause.

On container ships, reefer containers are often the ETO's responsibility. My duties are:

• Before loading: check the reefer plan, the number of sockets available and the power capacity, so the generators can supply the load.
• Connection: connect the containers, check that each unit starts and runs at the set temperature, and report any wrong settings to the Chief Officer, because the set point is given by the shipper.
• Monitoring: check the units regularly through the remote monitoring system or by rounds, and record the temperatures as the company and the charterer require.
• Faults: repair simple faults if allowed by the company and the container owner, or inform the Chief Officer quickly, so the cargo owner can decide.

Reefer cargo is valuable and sensitive, so accurate records are important in case of a claim.

The emergency generator and the emergency batteries must be ready to supply the essential services if the main power fails. I keep them ready by:

• Testing the emergency generator at the intervals required by SOLAS and the company procedure, including automatic starting and supply to the emergency switchboard.
• Checking the batteries: charging system, voltage, electrolyte levels where applicable, terminals and ventilation of the battery room.
• Checking the emergency switchboard and the transfer from the main to the emergency supply.
• Checking the emergency lighting, communications and navigation equipment supplied from emergency power.

I also make sure the fuel tank for the emergency generator is full and the starting arrangements are working. I record every test in the PMS and the logbook, because inspectors check these records carefully.