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Modular variable speed drive for HVAC systems PDF Stampa
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30 Aprile 12012

Siemens Energy-efficient modular variable speed drive for HVAC systems

The Siemens Building Technologies Division has just introduced the G120P variable speed drive for HVAC systems. The device has a modular structure, which makes individual components easy to replace. Various user-friendly functions ensure high energy efficiency and safety while keeping operating costs low. Thanks to protection classes IP54 and IP55, the G120P variable speed drive can also be used under harsh environmental conditions.
The Siemens G120P variable speed drive is suitable for applications that require an economical, energy-efficient and easy-to-operate drive for pumps or fans. It operates in a power range from 0.37 to 90 kilowatts (kW). The device has a modular structure, consisting of a control unit, the power module and an operating panel (basic operating panel BOP-2, or intelligent operating panel IOP) or a blanking cover. This design enables individual components to be exchanged without having to replace the entire drive. For example, a power module can be exchanged without reconfiguring the entire device or rewiring the signal and bus cables.
A high protection class, either IP55 (with the BOP-2 or blanking cover) or IP54 (with IOP), allows the variable speed drive to be used under harsh environmental conditions at temperatures up to 60°C, for example for controlling the speed of fans and recirculation pumps in heating and cooling systems. The new variable speed drives replace the Siemens SED2 devices.
The G120P variable speed drive is tailored to the needs of pump installations and ventilation systems and therefore offers numerous safety features. The device can routinely detect different events (such as overloaded motors, pumps that are blocked or have run dry, blocked fans, cracked belts, etc.) and respond to them immediately, for example by shutting down the pump or fan, triggering an alarm or starting a predefined process. When used in ventilation systems, the G120P automatically switches to emergency mode in the event of a fire. As a result, the overpressure generated by the ventilation is retained as long as possible, and the escape routes remain smoke free.
The G120P has various functions that improve energy efficiency for operating HVAC applications and systems economically. For example, the device is characterized by very low apparent power. The integrated hibernation function supports an energy-efficient and wear-reducing idle mode, depending on the current requirements. Because the drive automatically switches to mains operation at nominal speeds, it can cut energy consumption by as much as three percent. In addition, the variable speed drive has a low impact on the power grid and meets the IEC/EN 61000-3-12:2011 standard without additional components such as line reactors. A comprehensive fan, filter and motor monitoring system is integrated into the device to avoid loss of HVAC plant and rising operating costs. Flow optimization in U/f mode and during vector control adapts the motor magnetization to the partial load of the pump or fan. This helps increase motor efficiency under partial load, which substantially increases the efficiency of the overall system.
Plug connections for motor and power cables on the power modules up to frame size C and screwless terminals on the control unit permit easy installation of the G120P variable speed drive. The Starter software, which comes with several application wizards, is available to facilitate commissioning. The variable speed drive also has an integrated MMC (Micro Memory Card) slot for commissioning and diagnosis. This makes it possible to preconfigure the parameters for entire series of variable speed drives and to back up the settings.
The I/O and field bus interfaces, such as Modbus RTU, USS and BacNet MS/TP, are customized to the special requirements of HVAC. This allows the variable speed drive to be integrated easily into building management systems such as Siemens Desigo.
The G120P models with protection classes IP54 and IP55 are available now, and a device with the lower protection class IP20, which is suitable for panel mounting, will follow later this year.
The G120P frequency converter is part of Siemens' Environmental Portfolio. In fiscal 2011, revenue from the Portfolio totaled about €30 billion, making Siemens one of the world's largest suppliers of ecofriendly technologies. In the same period, our products and solutions enabled customers to reduce their carbon dioxide (CO2) emissions by nearly 320 million tons, an amount equal to the total annual CO2 emissions of Berlin, Delhi, Hong Kong, Istanbul, London, New York, Singapore and Tokyo.

Ritorno all'Indice
05 Aprile 2012
Desigo V5: Innovations from Siemens increase building efficiency
The Siemens Building Technologies Division has introduced version 5 of its Desigo building automation system. Its innovative products such as Total Room Automation as well as efficiency features, like RoomOptiControl and Eco Monitoring, give building operators and users an active role in energy management, leading to permanent reductions in energy and maintenance costs.
A state-of-the-art building automation system is always optimized for energy-efficient operation. However, these optimized settings may start to drift over time. One of the underlying causes is often a lack of transparency for users who simply don't know how the setpoint changes they make can impact energy consumption. This is particularly true for air-conditioned rooms which are also equipped with lighting and sun protection controls. The new version of Desigo keeps room users and building operators apprised of the building's efficiency status. Feedback to users is given using the innovative Green Leaf display, adapted to the expertise and control options of each user group. The system makes it possible to change settings if needed to restore optimal energy efficiency. A study by Technische Universität München (TUM) indicates that by actively involving operators and users in the energy management of a building, energy consumption can be reduced by up to 25% without affecting comfort.
Total Room Automation offers energy savings without reducing comfort
The open, programmable room automation range Desigo Total Room Automation (TRA) is a holistic solution encompassing the HVAC, lighting and shading disciplines. Desigo TRA uses an innovative efficience feature called RoomOptiControl. It automatically detects unnecessary energy consumption in the room and notifies users by changing the color of the Green Leaf icon on the QMX3 room control unit: If room operations are energy efficient, this icon is green. If settings made by a room user lead to unnecessary energy consumption, the icon turns red. To reset room control to energy efficient operation, the user simply presses the display and the Green Leaf icon returns to green.
Using BACnet/IP, PXC3 room automation stations—also part of the TRA package—are integrated seamlessly into the PX automation level with its primary systems (heating generators, HVAC main units and cooling generators). The primary systems are controlled directly through the demand signals from the rooms. This means that the primary systems are only turned on if needed and their operation is adjusted so it meets the room requirements without exceeding them. One room automation station can cover multiple rooms. TRA offers complete integration of KNX, DALI and EnOcean devices; existing or new sensors and actuators from Siemens can be incorporated as well.
Eco Monitoring to reduce energy consumption and wear
Eco Monitoring is another innovative efficiency feature of Desigo. It monitors ongoing operations of HVAC systems based on energy-related quality condition indicators such as readings from temperature, humidity and pressure sensors, runtime, switching behavior and operational performance of the systems. Should deviations from the target state, inefficient operations or increased energy consumption occur, the building operator is notified via the Green Leaf display on the Desigo Insight management station. Current and future international standards (such as EN 15323:2007) require such a feature in order to optimize building operations over the long term.
Desigo Eco Monitoring not only helps optimize energy consumption, it also reduces wear. Thanks to its dynamic behavior and timely reporting, the Eco Monitoring feature recognizes unfavorable system operations early on, allowing operators to intervene immediately before any negative impact occurs. If desired, operators can choose to be notified of unusual events via text messaging (SMS), fax or e-mail.
Expanded networking of the automation level
Starting with version 5, Desigo also offers expanded end-to-end networking of the automation level. Enhanced support for communications standards ensures efficient system integration. The PXC series of compact automation stations has a higher number of universal inputs/outputs, which makes them much more flexible. To protect existing investments, different device generations, such as PTM and TX I/O modules and RXC room controllers, can be used in parallel on the same PX automation station.

Ultimo aggiornamento Lunedì 30 Aprile 2012 10:04