AS/NZS 3000:2017 - Electrical Installations Standard

Identify an Australian or International Standard (must have Engineering applications).

Define the attributes of the Standard and its broad applications.

Describe how the Standard applies to a specific Engineering product, service or system (use a an explicit example)

About AS/NZS 3000:2017 standard

Standards Australia is an organization which was established in 1922 and is identified as the peak non-government standards organization body in the country (Standards Australia, 2018). The organization is recognized as the representative body of Australia on the Pacific Area Standards Congress (PASC) (Pascnet.org, 2018). The International Organization for Standardization (IOS) is also having Standards Australia as a member association (guidelines et al., 2018) and the Standards Australia is an integral part of the International Electrotechnical Commission (IEC) as well (Commission, 2018). The organization takes part in the major standard-related exercises which provide innumerable benefits to the country. It also acknowledges the good work in the industrial design sector in the form of the Australian International Design Awards (Good Design, 2018). The organization develops standards in joint activities with the Standards New Zealand in form of AS/NZS and the notable standard in electrical maintenance and installation sector is the AS/NZS 3000:2017 (Standards.govt.nz, 2018).

The standard is a general guideline for the electrical equipment installations and the proper maintenance of them (Barrett 2013). The standard specifies the wiring rules and the classification of the electrical equipments as well. It follows the electrical engineering sector with various guidelines and definition described for the electrical instruments and methods regarding the selection of the equipment, measurement, arrangement of the electrical installation and the control of the electrical installation. It also specifies the mode of operation during the emergency situation as it incorporates the fault protection guidelines, protection against overcurrent, fault current and appropriateness of additional equipment for the protection of the residual current devices. The general application of the standards adds the adverse cases like protection against under voltage, protection against overvoltage. The guidelines acknowledge the process of installation of the wiring system and the types of it along with a specific focus on the specified current carrying capacity of the conductors to be used in the installation. It describes the underground wiring systems and aerial wiring systems as well (Noone 2013). It defines the safety measures for the electrical instruments or accessories in the form of safety code and the specified education required for the electrical workforce (Lovrencic and Gomišcek 2014). It helps the industrial world to properly operate the electrical instruments like converter, transformer, motors, capacitors, circuit breakers and high voltage transmission devices. The guideline also specifies the earthing functions, systems, arrangements and equipment. Hence it has a wide range of applications in cases of electricity generation, transmission, distribution systems, the safety of workplaces, and qualification of the workers.

Attributes of AS/NZS 3000:2017 and its applications

As mentioned above, the guideline covers the definition of the major electrical equipments and the suitable ratings and procedure of them for the installation, the paper will discuss the implications of the concerned standards in the industry.

The standard follows the specified definition of the significant industrial equipments and the classification of them.

According to the guidelines, the protection against electrical shock does not depend only on the basic insulation in these sorts of equipments. These equipments have an extra safety precaution in the accessible conductive parts attached to the protective earthing conductor in such a manner that the basic insulation failure will not make the accessible parts become live.

The protection against the electric shock does not depend only on the basic insulation in this case as well and these equipments involve additional safety measures such as double insulation or reinforced insulation and have no connection on the protective earthing conductor in installation.

The class 3 equipments are specified as the equipments which depend on the supply at Safety Extra Low Voltage (SELV) for the protection against electric shock and the equipments which cannot generate the voltage more than the same in SELV.

A device that is designed to open a circuit to limit the flow of the instantaneous fault current is known as fault current limiter as per the guidelines.

Basic insulation:

According to the guidelines, the insulation subjected to the live parts to serve the basic protection is stated as the basic insulation.

It is separate insulation added to the basic insulation in order to provide the protection against the electric shock when the basic insulation fails to operate.

As per the guidelines the combination of basic and supplementary insulation are described as Double insulation.

It is one single insulation system subjected to the live parts which serves the protection against the electric shock, equivalent to the double insulation.

Considering the wiring system as one of the major discussed part in the standards, the guideline describes the types of the wiring system and the suitable atmospheric presence for the installation of the wiring system.

The wiring systems which will be selected, must align with the highest and lowest local ambient temperature. The current carrying capacity is generally selected in accordance to the ambient temperature and for the cables on air, 40 degree must be assumed for Australia and for the underground cables the ambient temperature is 25 degree to be assumed for Australia. The wiring systems are stated to be protected against the effects of the heat from the external sources by using the shielding method or by placing it far away from the source of heat. The temperature rise can also be reduced following the mechanism of limiting the current flowing through the conductor and by the selection of a system which has inbuilt feature to manage the temperature rise. The standards provide the appropriate guidelines for the installation of the wiring systems regarding the presence of water and high humidity.

AS/NZS 3000:2017 guidelines for electrical equipment installations

It is evident that an appropriate selection of the wiring systems and the installation is subjected to the minimization of the mechanical damage and the suitable protection to minimize the mechanical damage according to the standards can be achieved by concentrating on the below-mentioned points:

• Mechanical characteristics of the wiring systems.
• Selection of the location.
• Arrangement of the additional general and local mechanical protection.

The rigidity of the installation must be served on strong basis as the vibration related to the wiring systems will damage the efficiency of the wiring system (Gelonese 2017). The standards also defines the major concern of the effect of other mechanical stresses affecting the wiring system and the wiring systems are to be selected and installed in such a manner that it will minimize the damage of the cable insulation. The Standards defines the strategies to reduce the damage which are as follows:

• Usage of appropriate fixings for various sizes and types of cables that will grip the cable without any sort of damage.
• Usage of suitable connections according to the size and type of the cable that will reduce the presence of immense mechanical strain at the joints.
• Sharp attention to the minimum bending radius of the cables.
• The possible arrangement of support at frequent intervals to minimize the mechanical stress resulting from the mass of the cables of the wiring systems.

The current carrying capacity and the operating temperature in wiring system are specified by the standards. The standards also described that the total sum of the current carrying capacity of the different cables connected in parallel can determine the current carrying capacities of the circuits consisting with multi core cables or groups of single core cables and that is possible with the clauses specified in the standards such as the cable should not be less than 4 mm2, the cooling of the cables or the groups must not be affected by the grouping of the cables and the load current to be shared by each of the cables or the groups must be enough to eradicate any sort of overheating of any cable or group. The standards mentioned the different regulations for the circuit breakers and the High Rupturing Fuses (HRC) for overload operating characteristics like the current rating of the HRC fuses must not exceed 90 percent of the current carrying capacity of the conductors and the current rating capacity of the circuit breakers must not be higher than the current carrying capacity of the cables.

The installation conductors are specified by the colour codes for smooth identification of them in the installation of the wiring systems and the colour code that is to be maintained for the identification of the purpose of the cables are prescribed in the standards. The standards clarify that the green or yellow will be followed for protective earth and equipotential bonding. Neutral will be followed by black or light blue and any colour other than the mentioned ones will follow the active cable.

The AS/NZS 3000:2017 has significant implications in the electrical equipment settings and is the authorized guidelines for the electrical works throughout the countries. The Australian standards for the electrical works are continuously working on the major updates in the electrical field as it is evident that the technological advancement in the field of electrical engineering along with the wiring will be responsible for further and crucial modification in the guidelines specified in the standards. The standards has major significance in the safe conduct of the electricity generation, transmission and distribution as the procedure related to these events are specified in the standards with proper degree of safety measurement. The standards clarified the proper method of assessment of the electrical instruments and the suitability of those components in various cases of electrical installation.

References:

Barrett, R., 2013. Operating temperature of current carrying copper busbar conductors.

Commission, I. (2018). Welcome to the IEC - International Electrotechnical Commission. [online] Iec.ch. Available at: https://www.iec.ch/

Gelonese, G.A., Embertec Pty Ltd, 2017. Electrical device installation improvement. U.S. Patent 9,841,454.

Good Design. (2018). Good Design Australia | Good Design Awards. [online] Available at: https://good-design.org/

guidelines, Y., updated, A., standards, I. and out, G. (2018). ISO - International Organization for Standardization. [online] Iso.org. Available at: https://www.iso.org/home.html

Lovrencic, V. and Gomišcek, B., 2014, May. Live working as an example of electrical installation maintenance with the zero accidents philosophy. In Live Maintenance (ICOLIM), 2014 11th International Conference on (pp. 1-8). IEEE.

Noone, B., 2013. PV integration on Australian distribution networks. The Australian PV Association, UNSW, Australia.

Pascnet.org. (2018). PASC | Pacific Area Standards Congress. [online] Available at: https://pascnet.org/

Standards Australia. (2018). Standards Australia - Standard Organisation in Australia. [online] Available at: https://www.standards.org.au/

Standards.govt.nz. (2018). Standards New Zealand. [online] Available at: https://www.standards.govt.nz/