Last edit: 28/06/2023
Chapter 3 of the Standard provided the fundamental terms and definitions. The definitions are divided in paragraph as follow:
3.1 General terms
3.2 Constructional units of assemblies
3.3 External design of assemblies, where we find:
3.3.1 open-type assembly: assembly consisting of a structure which supports the electrical equipment, the live parts of the electrical equipment being accessible
3.3.2 dead-front assembly: open type assembly with a front cover; live parts may be accessible from directions other than the front
3.3.3 enclosed assembly: assembly which is enclosed on all sites with the possible exception of its mounting surface in such a manner as to provide a defined degree of protection
3.3.4 cubicle-type assembly: enclosed assembly of the floor-standing type which may comprise several sections, sub-section or compartments
3.3.5 multi-cubicle-type assembly: combination of a number of mechanically joined cubicle-type assemblies
3.3.6 desk-type assembly: enclosed assembly with a horizontal or inclined control panel or a combination of both, which incorporates control, measuring, signaling apparatus, etc.
3.3.7 box-type assembly: enclosed assembly, intended to be mounted on a vertical plane
3.3.8 multi-box-type assembly: combination of a box-type assemblies mechanically joined together, with or without a common supporting frame, the electrical connections passing between two adjacent boxes through opening in the adjoining faces
3.3.9 wall-mounted surface type assembly: assembly for installation on the surface of a wall
3.3.10 wall-mounted recessed type assembly: assembly for installation into a wall recess, where the enclosure does not support the portion of wall above
3.4 Structural parts of assemblies
3.5 Conditions of installation of assemblies, where we find:
3.5.1 assembly for indoor installation: assembly which is designed for use in locations where the normal service conditions for indoor use are fulfilled
3.5.2 assembly for outdoor installation: assembly which is designed for use in locations where the normal service conditions for outdoor use are fulfilled
3.5.3 stationary assembly: assembly which is designed to be fixed at its place of installation, for instance to the floor or to a wall, and to be used at this place
3.5.4 movable assembly: assembly which is designed so that it can readily be moved from one place of use to another
3.6 Insulation characteristics, where we find:
3.6.3 overvoltage: any voltage having a peak value exceeding the corresponding peak value of the maximum steady-state voltage at normal operating conditions
3.6.6 power-frequency withstand voltage: r.m.s value of a power frequency sinusoidal voltage which does not cause breakdown under specified conditions of test
3.6.7 impulse withstand voltage: highest peak value of impulse voltage of prescribed form and polarity which does not cause breakdown of insulation under specified conditions
3.6.8 pollution: any addition of solid, liquid or gaseous foreign matter, that can result in a reduction of the dielectric strength or surface resistivity of insulation
3.6.9 pollution degree: conventional number based on the amount of conductive or hygroscopic dust, ionized gas or salt, and on the relative humidity and its frequency of occurrence resulting in hygroscopic absorption or condensation of moisture leading to reduction in dielectric strength and/or surface resistivity
3.6.10 micro-environment: immediate environment of the insulation which particularly influences the dimensioning of the creepage distances
3.6.11 overvoltage category: conventional number based on limiting the values of prospective transient overvoltages occurring in a circuit and depending upon the means employed to influence the overvoltages
3.6.12 surge arrester, surge protective device, SPD: device designed to protect the electrical apparatus from high transient overvoltages and to limit the duration and frequently the amplitude of the follow-on current
3.7 Protection against electric shock
3.8 Characteristics, where we find
3.8.5 nominal voltage: approximate value of voltage used to designate or identify an electrical system
3.8.6 short-circuit current Ic: over-current resulting from a short circuit due to a fault or an incorrect connection in an electric circuit
3.8.7 prospective short-circuit current Icp: r.m.s. value of the current which would flow if the supply conductors to the circuit are short-circuited by a conductor of negligible impedance located as near as practicable to the supply terminals of the assembly
3.8.8 cut-off current, let-through current: maximum instantaneous value of current attained during the breaking operation of a switching device or a fuse
3.8.10.1 rated current: value of current, declared by the assembly manufacturer which can be carried without the temperature-rise of various parts of the assembly exceeding specified limits under specifies conditions
3.9 Verification, where we find:
3.9.1 design verification: verification made on a sample of an assembly or on parts of assemblies to show that the design meets the requirements of the relevant assembly standard
3.9.1.1 verification test: test made on a sample of an assembly or on parts of assemblies to verify that the design meets the requirements of the relevant assembly standard
3.9.1.2. verification comparison: structured comparison of a proposed design for an assembly, or parts of an assembly, with a reference design verified by test
3.9.1.3 verification assessment: design verification of strict design rules or calculation applied to a sample of an assembly or to parts of assemblies to show that the design meets the requirements of the relevant assembly standard
3.9.2 routine verification: verification of each assembly performed during and/or manufacture to confirm whether it complies with the requirements of the relevant assembly standard
3.10 Manufacturer/User, where we find
3.10.1 original manufacturer: organization that has carried out the original design and the associated verification of an assembly in accordance with the relevant assembly standard
3.10.2 assembly manufacturer: organization taking the responsibility for the completed assembly
The original manufacturer is the organization which carried out the original design and the associated verification of an assembly and verify the characteristics in accordance with the relevant assembly standard. Moreover, in case of the construction of the product is done by others, the original manufacturer establishes and publishes rules that have to be followed to replicate the prototype.
The assembly manufacturer (if different from the original manufacturer) builds the assembly starting from separate items and, following the original manufacturer’s rules, obtains the final product complying with the specimens done and verified by the original manufacturer.
Ultimately, the original manufacturer shall guarantee:
– Design verification on prototypes;
– Instructions for choosing and installing the components
Instead, the assembly manufacturer shall carry out:
– The choosing and the installation of the components following the original manufacturer’s instruction;
– The verification of derivated configuration;
– Routine verification