PKE Motor-Protective Circuit-Breakers with Electronic Wide Range Overload Protection
Eaton Expands its PKE Motor-Protective Circuit-Breakers with Electronic Wide Range Overload Protection.
Bonn,… As one of the leading manufacturers of components and systems for electrical engineering and automation, Eaton is launching a SmartWire-Darwin Module for the PKE Motor protective circuit breakers.
When it comes to the technical performance of motor-protective circuit-breakers, plant operators nowadays have the following key requirements: keeping the engineering and design requirements to a minimum; reducing the range of variants by the optimum adaption of ratings and increased system availability; and safety by the transfer of process data (condition monitoring). In this respect, motor-protective circuit-breakers with wide-range overload protection have key benefits compared to devices with thermal releases: Large setting ranges, low heat dissipation, tripping classes also higher than CLASS 10, precise and long-time stable tripping characteristics, as well as the possibility to read out parameter data.
Motor-protective circuit-breakers with electronic wide-range overload protection measure the current rise via the integrated current transformer in the trip block, and evaluate it via a special electronic circuit which sends a pulse via an actuator system to the switch mechanism. The voltage supply of the electronic circuit is implemented via a transformer. The opening time depends on the ratio of the tripping current to the setting current and is stored in the form of a long-time stable tripping characteristic curve.
Motor-protective circuit-breakers with electronic wide-range overload protection operate with a larger current transfer ratio. In this way, the device has a wide current setting range in the ratio 1:4 compared to conventional bimetal motor-protective circuit-breakers (bimetal 1:1.6). The large current setting ranges reduce the number of variants by up to 75 percent compared to bimetal trips. This minimises design engineering requirements and reduces costs. The benefits described can be implemented in the motor-protective circuit-breaker even more efficiently in a modular design: The basic unit of the PKE can be separated from the trip block (control unit). The plug-in design enables the control unit to be fitted easily into the basic module. Any functions required can also be later defined in the control unit without disconnecting the main current wiring.
Compared to the bimetal solution, PKE motor-protective circuit-breakers have up to 85 percent less heat dissipation, thus reducing energy consumption and costs. The temperature rise in the switching cabinet is also reduced.
The startup phase of a motor is always a critical period since the motor uses considerably more current during the start than during normal operation. PKE motor-protective circuit-breakers offer selectable trip classes for the current-dependent and delayed overload protection. The tripping characteristics of the overload release are determined by the tripping class to which it is assigned. For this tripping curves for continuous three and two-phase operation are stored in the device, and these can be selected as tripping classes (CLASS), according to the startup behaviour of the drive. Thanks to the adjustable tripping classes CLASS 5…20, optimum protection of drives for virtually all startup conditions is provided with one motor-protective circuit-breaker.
Previously, it was only possible to evaluate switch states or discriminate overload or short-circuit trip indications. PKE motor-protective circuit-breakers with electronic overload protection offer considerably more indication functions, as well as diagnostics, status or overload messages, right up to the actual current flow. The data of networked motor starters can be transferred directly via a fieldbus cable to the controller and made available for the entire installation, for example, for condition monitoring or remote maintenance. A Profibus and CANopen interface are at present available for the PKE. The increasing intelligence of motor-protective circuit-breakers extends the overall basic functions to cover aspects such as availability, efficiency and cost effectiveness.
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Eaton's Moeller Business
Since April 2008, Moeller has been a part of the Eaton Electrical Sector of the Eaton Corporation, a diversified power management company with 70,000 employees and an annual turnover of about US$ 11.9 billion in 2009. www.eaton.com/moellerproducts
Eaton's electrical sector
Eaton's electrical sector is a global leader in power distribution, power quality, control and industrial automation products and services. Eaton's global electrical product lines, including Cutler-Hammer®, Moeller®, Powerware®, Holec®, MEM®, Santak®, and MGE Office Protection Systems™ provide customer-driven PowerChain Management® solutions to serve the power system needs of the data center, industrial, institutional, government, utility, commercial, residential, and OEM markets worldwide.
Eaton Corporation is a diversified power management company with 2009 sales of $11.9 billion. Eaton is a global technology leader in electrical components and systems for power quality, distribution and control; hydraulics components, systems and services for industrial and mobile equipment; aerospace fuel, hydraulics and pneumatic systems for commercial and military use; and truck and automotive drivetrain and powertrain systems for performance, fuel economy and safety. Eaton has approximately 70,000 employees and sells products to customers in more than 150 countries. For more information, visit
For more information, visit www.eaton.com.