Provides guidance on acceptable limits of voltage fluctuations on the power supply network produced by industrial equipment.

Part 4 of this Standard provides guidance on the acceptable limits of voltage fluctuations at the point of common coupling caused by industrial equipment supplied from high or low voltage electricity supply systems.The switching of equipment or variations in its loading may cause changes in voltage which could result in the unsatisfactory operation of other equipment and undesirable effects such as flicker in incandescent lamps.Part 4 of this Standard is applicable to all electrical equipment other than that covered by AS 2279.3. In particular, this Part is intended for application to equipment which-(a) is intended exclusively for industrial, professional or commercial purposes and with a rating greater than 4.8 kV.A; and(b) produces voltage changes in the range of one change per day to 1800 changes per minute.In addition, it concerns specific equipment subject to individual consideration by the supply authority before it may be connected to the system. Equipment which would produce voltage fluctuations and would fall within the Scope of Part 4 of this Standard includes pump and compressor motors, welding plant, furnaces, elevators, equipment for manufacturing processes, mining, lighting and air conditioning. This Standard does not apply to voltage unbalance in supply systems or intermittent transient disturbances e.g. spikes and dips.

Obsolescent 2001Under Revision see DR 99020 First published as AS 2279.4-1985.Second edition 1991. First published as AS 2279.4-1985. Second edition 1991.