Consultant eNewsletter April 2009

Altivar® 21 Variable Frequency Drive receives global recognition its industry leading harmonics reduction in HVAC & Pumping applications

Schneider Electric was recently awarded the 2008 European HVAC Electric Drives Technology Innovation Award for the technology utilized in the Altivar 21 electric drive. The Altivar 21 is the industry leader in harmonic reduction for AC Drives for HVAC and Pumping applications. This award is given to companies that successfully develop and introduce new technologies, formulate well-designed product families, and make significant contributions to the industry.
Designed specifically for HVAC systems, the Altivar 21 drive was introduced in 2006. It meets or exceeds the harmonic reduction by traditional line reactors utilizing innovative power conversion design and reduced DC bus capacitance. Compact in size, the power rating range is 0.75 KW (1 HP) to 75 KW (100 HP), which covers the full range of construction projects. It can also reduce noise pollution, through smooth and silent operation and offers many communication cards including; BACnet, LonWorks, APOGEE FLN, and other available networks.

Altivar 21 offers:

Reduced harmonics without the use of line reactors
Reduced installed cost
Proven quality and reliability
Simple installation
Energy efficiency
Compact size

Motor noise reduction

Learn more about the Altivar 21 and the Frost & Sullivan 2008 European HVAC Electric Drives Technology Innovation Award online or email us at HVAC@us.Schneider-Electric.com

Line Reactors, Harmonics and Drives, OH MY!

Power line harmonics and harmonic distortion are words found in almost every specification for variable frequency drives. An increasing number of electronic devices are being installed and retrofitted into buildings that generate power line harmonics, including devices that convert AC power to DC power. This intermittent current draw, caused by the capacitors charging in these devices, can have high peak current values. Managing these high peak current values and managing the input current waveform are the keys to mitigating power line harmonics.

While harmonics is a term referred to regularly, there are few industry guidelines on this subject. IEEE 519-1992, recommended Practices and Requirements for Harmonic Control in Electrical Power Systems and is often referenced when discussing harmonic mitigation. However, this standard was developed to cope with harmonic issues in electrical transmission lines and power grids and is a systems standard which cannot be effectively applied to individual products. The international standard IEC EN61000, Limits for Harmonic Current Emissions, is being increasingly referenced. IEC EN61000 part 3-12 discusses harmonic current limits produced by equipment connected to public low voltage systems. This IEC standard provides criteria for evaluating individual products. For compliance to IEC EN61000 the THDI must be less than 48%.

Our S-Flex enclosed drive packaged with the Altivar® 21 Variable Frequency Drive (VFD) was designed specifically for commercial HVAC and pump applications. This drive package offers all the benefits of metal enclosure but includes a unique and effective approach to reducing harmonics, called Reduced Harmonics Technology (RHT). The S-Flex drive offers a distinctive optimized power section and a powerful motor control algorithm that significantly reduces harmonic currents without the use of additional harmonic reduction devices like line reactors or DC chokes.

Learn more about line reactors, harmonics and variable frequency drives online.