Communication-capable Circuit Breakers

WL Circuit Breaker

Important functions/parameters for communications

Thanks to their modular construction and numerous I/O modules, WL Circuit Breakers offer flexible system solutions. These solutions include load management, alarms and additional tripping conditions via the extended protective functions. Although the utilization of these functions is also possible without the use of communications, their benefits can be fully utilized when used in communication applications.

Load Management

A circuit breaker with ETU745 or higher, offers two current setpoint values for local load management, the upper setpoint being that of load shedding, the lower setpoint being that of load restore.

Note: These setpoints will not effect the circuit breaker tripping function. If the current exceeds the set load shedding value in one phase, a load shedding warning will be generated. A load restore will only be generated when this value drops below the setpoint in all three phases. The warning messages are directly displayed by the BDA. However, they are also stored in the event log where they are labeled with a time stamp.

Note: The event log is only available with the COM16.

The respective process for the load restore threshold is reversed if all three phases fall short of the setpoint, and a load shed warning will be generated. If only one of the three currents exceeds the setpoint, a load restore event will not be generated.

In order to avoid load shedding on the basis of short-time current peaks and valleys, they can be delayed by a delay time t x which can be set to between 1 s and 15 s.

The load management parameters can be found in the parameter tree of the BDA.

The load shedding/load restore signals are available as outputs of the digital output module, which are provided with a rotary selection switch.

Extended Protective Function

The extended protective function of the metering modules adds additional tripping functions. The options listed in table 2-8 can be used as additional monitoring functions.

Figure Load shedding and restore are explained in this graphic. It’s based on the assumption

2-8of a WL Circuit Breaker with an overload setpoint of 1000 A.

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WL MODBUS Communication and Electronic Accessories • January 2005

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Siemens UL 489, UL1066 Important functions/parameters for communications, Load Management, Extended Protective Function

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.