Exam Question
2. a) What are the advantages and advantages of Neutral insulated system(6)
b) An Alternator does not build up any voltage after start. Describe step by step procedure to
solve the problem for all reasons.(10)
ETO
ETO Exam papers
📅 Mar 2026
Reference Answer
### Part A: Advantages and Disadvantages of a Neutral Insulated System
A neutral insulated system, also known as an unearthed IT (Isolé Terre) system, is commonly used in marine applications where continuity of power to essential services is paramount. The neutral point of the power source (generator or transformer) is not intentionally connected to the ship's hull (earth).
#### Advantages (6 Marks)
1. **Enhanced Continuity of Supply:** This is the primary advantage. A single phase-to-earth fault does not cause an immediate trip of the protective device. The system can continue to operate, allowing the vessel's crew to locate and rectify the fault at a convenient time without losing power to critical machinery such as steering gear, main engine lubrication pumps, or navigation equipment. This prevents a potential blackout situation from a single insulation failure.
A neutral insulated system, also known as an unearthed IT (Isolé Terre) system, is commonly used in marine applications where continuity of power to essential services is paramount. The neutral point of the power source (generator or transformer) is not intentionally connected to the ship's hull (earth).
#### Advantages (6 Marks)
1. **Enhanced Continuity of Supply:** This is the primary advantage. A single phase-to-earth fault does not cause an immediate trip of the protective device. The system can continue to operate, allowing the vessel's crew to locate and rectify the fault at a convenient time without losing power to critical machinery such as steering gear, main engine lubrication pumps, or navigation equipment. This prevents a potential blackout situation from a single insulation failure.
Full answer on MeoMock — surveyor-grade reference answers for 7,000+ written exam questions.
Prepare on Android — MeoMock on Google Play