Q3. a) What are the benefits of 3 Ph supply over a single-phase supply system? (6)
b) Explain 3-wire and 4-wire 3 phase a.c. distribution systems. (10)
Q5. With the aid of a simple circuit diagram, explain the electrical distribution system for essential loads on board a cargo ship. (16)
Q8. With reference to a three-phase shipboard electrical distribution system.
a) Enumerate the advantages of an insulated neutral system (4)
b) Enumerate the disadvantages of an insulated neutral system (4)
c) Compare the use of an insulated neutral system as opposed to use of an earthed neutral system with regards to the risk of electric shock from either system. (8)
Q2. With reference to a three-phase shipboard electrical distribution system:
(a) Enumerate the advantages of an insulated neutral system (4)
(b) Enumerate the disadvantages of an insulated neutral system (4)
(c) State why an Earthed neutral system may be earthed through a resistor (4)
(d) Compare the use of an insulated neutral system as opposed to the use of an Earthed neutral system with regard to the risk of electric shock from either system (4)
Q4. With reference to a three-phase shipboard electrical distribution system:
a) Enumerate the advantages of an insulted neutral system. (4)
b) Enumerate the disadvantages of an insulted neutral system. (4)
c) Describe how the Earthed neutral system is earthed. (4)
d) Compare the use of an insulated neutral system as opposed to the use of an Earthed neutral system with regard to the risk of electric shock from either system. (4)
Username or email address *Required
Password *Required
Note: Entering wrong username in the login form will ban your IP address immediately. Entering wrong password multiple times will also ban your IP address temporarily.
Log in
Lost your password? Remember me
No account yet?
