CurveSelect tool updated to easily optimise protection selectivity

CurveSelect can be used to assess not only interaction between a wide range of Eaton products, but also between Eaton products and those of other manufacturers.

For effective and economical protection of power systems, the tripping curves of the protection devices must be accurately matched to the specifications of the equipment used. However, in practical applications, it is almost always necessary to use several protection devices that work in conjunction with each other. To determine the exact tripping response of the devices used in such applications, the actual settings of each device must be taken into account. This is a difficult and time-consuming process when working simply with printed tripping characteristics.

CurveSelect makes this task faster, easier and more certain. An Excel-based software tool, CurveSelect allows the precise tripping curves for all devices to be generated and documented. It also supports simultaneous display of curves for multiple devices using the same time and current scales.

Eaton has recently carried out exhaustive tests to confirm the suitability of products in its popular motor control range for use with the latest IE3 high-efficiency motors. Today, all PKZ and PKE motor-protection circuit breakers have been shown to be suitable for efficient and dependable control of IE3 motors and have, therefore, been designated ‘IE3 ready’. CurveSelect does now reflect the amended characteristics of these devices.

Additional Eaton devices with characteristics pre-loaded in CurveSelect include NZM, IZM and BZM circuit breakers; ZB and ZEB thermal overload relays; FAZ miniature circuit breakers with B, C, D, K, S and Z tripping characteristics; and type gL and gG fuses. It is possible to enter additional tripping characteristics so that medium-voltage circuit breakers and non-Eaton devices can be analysed.

The ability to define custom curves means that specific scenarios can also be examined. Using the motor starting curves, for example, it is possible to check whether a given protective device will allow trip-free starting of a particular motor. Users of CurveSelect can also determine whether incoming circuit breakers comply with prescribed medium voltage protection requirements and whether existing devices can provide sufficient protection for planned extensions.