IEC 60092-504:2001 pdf download

IEC 60092-504:2001 pdf download.Electrical installations in ships -Part 504:
Special features – Control and instrumentation.
3.13
integrity
capability of a system to satisfactorily perform the required functions under all the stated conditions within a stated period of time
3.14
machinery control room
room or spaces where centralized controls and measuring and monitoring equipment for main
equipment and essential auxiliary machinery are located together with the appropriate means
01 communication
3.15
maintainability
ability of an item under given conditions of use, to be retained in, or restored to, a state in which it can perform a required function, when maintenance is performed under given conditions and using stated procedures and resources
3.16
monitoring functions
functions intended to collect data from equipment and systems for the purpose of display and recording
3.17
protection functions
functions intended to prevent damage to equipment or systems In the event of a fault
3.18
reliability
ability of an item to perform a required function under given conditions for a given time interval
3.19
safety functions
functions intended to prevent narm or danger to personnel
3.20
software
program, procedures and associated documentation pertaining to the operation of a computer system and including application (user( program. middleware arid operating system (firmware) program
3.21
system
collection of components organised to accomplish a specific function or set of functions
3.22
usability
extent to which a system can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction In a specified context of use
4 General requirements
4.1 Dependability
Systems shall be suitable for the user, the task and the application.
System Integrity shall be appropriate for the functions supported. with due regard to factors such as availability, reliability and maintainability.
4.2 Safety
Systems shall be designed such that risk of harm to persons or the environment is reduced to a level acceptable to the appropriate authority, both in normal operation and under failure conditions. Functions shall be designed on the tail-to-sate principle.
4.3 SegregatIon
Systems shall be designed such that failure of one component part or sub-system will not unduly affect any other system, sub-system or component and, as far as is practicable, shall be detectable,
Protection (safety) functions shall be independent of control and monitoring (alarm) functions. As far as is practicable, control and monitoring (alarm) functions shall also be independent.
Standby systems, or other redundancy arrangements, are to be functionally independent.
4.4 Performance
Systems shall maintain specified levels of performance in operation, and where necessary, under fault conditions.
Repeatability and accuracy shall be adequate for the proposed use and shall be maintained at their specified value during their expected lifetime and normal use,
Systems shall be stable throughout their operational range.
4.5 UsabIlity
Systems shall be readily usable under all intended operating conditions and shall support effective and efficient operation,
Adequate saleguards against incorrect operation shall be provided.
4.6 Integration
Where safety of personnel may directly depend on correct system operation or failure, such systems shall not be integrated with, or be mutually dependent upon, any other system, except those providing complementary functions.
Where safety may indirectly depend on system operation or failure, the integrity of the integrated system shall be to the satisfaction of the appropriate authority.
4.7 Dev&opment actIvities
Activities undertaken in the development process, from initial design through to eventual realisation, and any modifications in use thereafter, shall be planned and structured in a systematic manner, and are to be properly managed. Persons responsible for carrying out these activities shall be competent to do so.
Activities, scopes, responsibilities and competencies shall be documented.
6 Design
6.1 Environmental and supply conditions
Equipment shall be designed to operate satisfactorily within the expected environmental andsupply conditions,with due regard to the limits specified in Annex B of lEC 60092-101.
6.2Circuit design
Circuits shall be designed to enable efficient test,calibration，maintenance and repair.Preferably, they shall be suitable for repair by unit or card replacement. In some cases, it maybe desirable to provide simulation circuits or similar means to check correct operation of theequipment.
6.3Mutual effects
Systems shall be arranged such that faults will not affect any function provided by any othersystem.
6.4 Electrical subdivision
Design of circuits shall be such that there is no direct connection to any point of the ship’s mainpower supply system, e.g. isolating transformers shall be used for power supplies.The chassismay not form part of any circuit, except earthing for functional reasons.