MAIN ENGINE SLOW DOWN & PROPER CHECKING OF ELECTRIC MOTOR | MARINE ELECTRICIAN

Summary

In this detailed troubleshooting session, an engineer responds to a slow down alarm caused by a tripped main loop oil pump. The engineer performs a thorough inspection, checking the control panel and motor windings while ensuring safety protocols. Key steps include measuring winding resistance and confirming the motor's integrity by removing terminal plates for accurate readings. After assessing the motor condition and working with a second engineer to address mechanical issues, the team successfully reconnects the power cables and confirms the motor's stable operation, illustrating the importance of careful diagnostics in maintaining engine efficiency.

Takeaways

• 🔧 A slow down alarm was triggered due to the main loop oil pump tripping, prompting an investigation into the cause.
• 👀 The technician performed a visual inspection of the control panel and motor terminals for any signs of damage or abnormalities.
• ⚡ Safety first: The technician confirmed that the circuit was dead before proceeding to isolate the motor by disconnecting it from the control panel.
• 🔍 The technician explained the differences between delta and Y connections while checking the motor windings.
• 📏 Accurate measurements: The technician emphasized measuring the windings without the plates for more precise readings.
• 🔌 Using a multimeter, the technician checked the resistance between pairs of cables (u1, u2; v1, v2; w1, w2) to assess the windings' condition.
• 🌍 Ground checks: The technician measured line to ground for each cable to confirm the insulation integrity.
• 🛠️ After verifying that the windings were in good condition, the technician prepared for the second engineer to lift the motor for further inspection.
• 🔄 Once mechanical issues were resolved, the technician reconnected the cables and ensured proper insulation with shrinkable tubing.
• ✅ Final checks confirmed that the motor was functioning steadily without issues after the repairs.

Q & A

What was the initial alarm reported in the script?

The initial alarm reported was a slowdown in the main engine due to a trip in the main loop oil pump.

What steps did the technician take after receiving the alarm?

The technician visually inspected the control panel, checked the overload current relay, and reset the Eocr before proceeding with further troubleshooting.

Why did the technician choose not to test the motor initially?

The technician avoided testing the motor immediately because it was a large motor, and there was a risk of burning it out.

What specific checks did the technician perform on the motor's windings?

The technician checked the windings line-to-line and line-to-ground, looking for continuity and signs of grounding.

What are the two wiring orientations mentioned in the script?

The two wiring orientations mentioned are the Delta connection and the Y connection.

Why did the technician remove the terminal plates during the winding check?

The technician removed the terminal plates to obtain more accurate measurements, as impurities between terminals could affect the readings.

What precautions did the technician take before working on the motor?

The technician tested to ensure the line was not live before touching any connections, confirming it was a dead circuit.

What final checks were performed after the repairs were made?

After repairs, the technician checked the current readings to ensure they were steady and verified that the motor was functioning properly.

What materials did the technician use to insulate the connections after reassembly?

The technician used shrinkable tubing to properly insulate the gland after reassembling the connections.

How did the technician confirm that the motor windings were in good condition?

The technician measured the windings and found that they showed good continuity with no grounding, indicating that they were in good condition.