Introduction, Safety Briefing and Objectives of the Course
Introduction, Safety Briefing and Objectives of the Course
Introduction
In marine field, voltage above 1kv is called as high voltage and voltage below 1 kv (1000v ac) is called as low voltage. 3.3 kv, 6.6kv and 11kv are the typical HV systems in marine. The usage of high voltage electrical systems in ships has been in an increasing state in the recent years. Though the applications of high voltage systems in ships are inevitable, the risks and consequences of electrical accidents involving high voltage are higher than low voltage installations. The main hazard for persons working in HV systems is electric shock. It is very important to follow safe working practices as per the guidelines. The design of electrical distribution system involving high voltage must be certified with the authorised sources. The HV electrical personnel should be trained on safety related work practices. It is also very important to secure the HV work place and danger notices have to be posted.
The HV electrical distribution systems in the ships includes switchboards, power panels, generators, essential loads, motor controllers, fuses, cables and protective devices and switch gears.
The various HV equipment which require HV installation are HV motors, HV generators, HV transformers, HV switchboard with HV protection devices, HV switch gear and HV cables. When working in these HV equipment, it is necessary to have a separate permit-to-work system. These equipment must be made dead or isolated or earthed before starting the work.
Electric propulsion with gas turbine or diesel engine driven power generation is used in hundreds of ships of various types. These electric propulsion systems require high current supply. The marine propulsion systems contain the integrated electric propulsion or full electric propulsion. For energizing the motors, three phase electricity generated either by the gas turbines or diesel generators or both is used. The main advantage of using electric propulsion system is less fuel consumption and maintenance.
Learning Objectives
At the end of this course, you will be able to
- Understand the importance of safety when working in High Voltage systems.
- Explain the High Voltage technology and its applications onboard ships, concepts and definitions.
- Understand the electrical hazards associated with High Voltage systems and their precautions Eg: Electric shock, Arc flash and Arc Blast.
- Describe the arrangement of High voltage installations, switch room, switch boards, transformers and earthing system.
- Explain the safety regulations regarding work on High Voltage installations.
- Explain the work permits and Procedures for preventing accidents while carrying out maintenance and repair.
- Understand the operation and safety features of High Voltage switch gear and the use of HV PPE.
- Understand the regulations governing High Voltage installations.
- Explain the concept of electrical stress, breakdown strength and ageing of high voltage electrical insulation structure.
- Describe the types of High Voltage distribution system, their construction, insulated and non-insulated system components, cables, fuses and protective devices.
- Understand how the safety documentation is issued and controlled.
- List out the safety lockout procedures and explain the Key Safes/Multi Hasp locking devices and isolation procedures.
- Describe the treatment of system neutral point.
- Describe the electrical propulsion systems.
- Explain about high voltage motor controllers
- Explain the construction and operation of High Voltage systems- High voltage motors, cyclo-converters, Frequency control and controlling of motors/propulsion drives, Transformers and other equipment.
- Understand the power management systems, instrumentation and high voltage measuring and testing equipment.
- List out the Polarization Index and IR test procedures for High Voltage equipment.
- Explain the ways of maintenance and fault identification in High Voltage system and procedure switching and isolation procedure using appropriate tools and PPE, VCB , key safe procedures.
- Describe the emergency procedures and related case studies.
- Demonstrate the High Voltage systems and procedure for carrying out work using appropriate tools and PPE.
