Communication-capable Circuit Breakers

WL Circuit Breaker

External power consumption of a WL Circuit Breaker with CubicleBUS

WL Circuit Breakers with CubicleBUS are designed to provide internal and external communication when the main contacts are open. It is therefore necessary to connect an external power supply.

General information

The current sensing devices of WL Circuit Breakers consist of two components. The Rogowski coils deliver the current measuring values, and the energy converters provide the trip units with power. For breakers without an additional external supply, the trip units are

already activated and monitor the current at minimum values of 80A for Frame Size II, and 150A for Frame Size III.

The current from the sensors are sufficient to not only activate the protective functions of the ETU745 or ETU748 trip units, but also to activate the display, however, the back-lighting requires an external power supply. If the CubicleBUS has been connected to a UL Listed 24V DC class 2 power supply, the display is fed with energy from this supply.

The display of the ETU776 only functions when an external CubicleBUS power supply has been connected. The protective functions are fully operational when primary current is flowing even though the display is not active.

If additional CubicleBUS components are applied on a WL Circuit Breaker, the breaker must be connected to an external UL Listed 24V DC class 2 power supply.

The CubicleBUS consists of four wires, two for the communications and two for the UL Listed 24V DC class 2 power supply. The CubicleBUS is connected to the external terminal X8.1 to X8.4.

Table 2-23To find a suitable external power supply for the WL Circuit Breaker with CubicleBUS the continuous current and the peak inrush current must be observed.

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WL MODBUS Communication and Electronic Accessories • January 2005

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Siemens UL1066, UL 489 specifications General information

UL 489, UL1066 specifications

Siemens UL1066 and UL489 are essential components in the landscape of electrical equipment, specifically in circuit protection and control. These standards ensure reliability, safety, and efficiency in various applications, including industrial, commercial, and residential settings.

The Siemens UL1066 is primarily focused on disconnect switches. These devices are designed to isolate electrical circuits, ensuring the safety of both personnel and equipment during maintenance or in case of faults. One of the key features of UL1066 disconnect switches is their high breaking capacity, enabling them to handle significant fault currents without failure. This characteristic is crucial in protecting downstream equipment from damage caused by short circuits. The UL1066 switches are also known for their robust construction, often featuring a metal enclosure that enhances durability and environmental resistance. Additionally, these switches can be operated manually or remotely, offering flexibility in operation and control.

On the other hand, Siemens UL489 circuit breakers provide comprehensive protection against overcurrents and short circuits. These devices not only interrupt fault currents but also protect connected devices from damage due to overload situations. Key features of UL489 circuit breakers include adjustable trip settings, which allow users to customize the response to overcurrent conditions based on specific application requirements. This adaptability makes them suitable for a wide range of environments, from large industrial plants to smaller commercial buildings.

Both UL1066 and UL489 products are constructed with advanced technologies, such as thermal-magnetic or electronic trip mechanisms in UL489 devices, ensuring precise and timely interruption of fault currents. These technologies promote energy efficiency and stability within electrical systems. In addition, many of these devices are equipped with indication features, providing clear visual status cues for quick assessment in emergency situations.

In terms of characteristics, both UL1066 and UL489 devices adhere to rigorous testing and certification processes to meet UL standards. This compliance assures users of their performance and reliability. Furthermore, the devices are designed to accommodate a wide range of operating temperatures and environmental conditions, making them versatile choices for various applications.

In summary, Siemens UL1066 and UL489 devices are paramount in ensuring safety and efficiency in electrical circuits. Their advanced features and robust construction make them indispensable in protecting both personnel and equipment in an array of industrial and commercial applications.