STULZ, Mirus, ebm-papst to host webinar on harmonic mitigation in data centres

FREDERICK, Maryland, 26 September 2021: STULZ, Mirus International and ebm-papst will be conducting part 2 of a e-discussion on harmonic mitigation in data centres, STULZ said through a Press release. The webinar is on September 28, the company added.

To improve energy efficiencies in today’s modern custom air handlers, highly efficient electronically commutated (EC) fans are often incorporated for air movement, STULZ said. This is because the fan systems can improve efficiencies over conventional AC motors equipped with variable frequency drives (VFDs) by 30% or more, it said. An EC fan incorporates a brushless DC permanent magnet motor (BLDC) controlled by an integrated rectifier, inverter and smart electronics.

BLDC motors, with efficiencies greater than 90%, provide a more effective ventilation system, so that ‘free cooling’ becomes more easily achievable, which contributes to the energy savings potential, it said. Also, air distribution can be improved with multiple fan arrays allowing upstream or downstream components, such as filters or heat exchangers, to receive a more even airflow, thereby improving air filtering and heat transfer efficiency, it added.

In striving towards reliable and efficient systems, one significant factor sometimes overlooked is electrical harmonic distortion, STULZ said. One of the few things common with AC/VSD and EC fan systems is that they are both harmonic generating, non-linear loads, it said.

Without proper harmonic mitigation, non-linear loads can distort the AC power distribution and possibly expose a mission-critical facility to electrical issues, such as overheating distribution equipment and failure of sensitive equipment connected to the same electrical bus, it added.

The speakers include Dave Meadows, Director of Technology, STULZ USA; Tony Hoevenaars, President and CEO, Mirus International; and Joe Landrette, Director, VAC & Data Centers and Digital Solutions, ebm-papst. According to STULZ, the webinar, scheduled for a 2pm (Eastern Time, US and Canada) start, will be useful to electrical engineers, mechanical engineers and end-users.

Cooling to the Green Deal with natural CO2 refrigerant systems

WELSHPOOL, United Kingdom, 17 August 2021: Invertek Drives showcased its dedicated VFD, Optidrive Coolvert, for use on CO₂ refrigeration display cases used in the retail sector. The company added that its Optidrive Eco operates on larger current refrigeration compressor racks and cold rooms.

Invertek make the announcement against the backdrop of the European Commission’s Green Deal, also referred to as Fit for 55, which sets out proposals to cut EU net greenhouse emissions by at least 55% by 2030, compared to 1990 levels. This could mean the current target of reducing fluorinated greenhouse gas (F-Gas) emissions by two-thirds by 2030, compared with 2014 levels, will be adjusted and tightened further.

The EU F-Gas Regulation brought a 44% reduction in the amount of available HFCs in the EU, compared to 2015. By 2030, the current regulation allows only 20% of HFCs being available, with stepped drops between then and now. This could change in the recast.

According to Invertek, the impact of both means there is a need to ramp up the use of natural refrigerants, such as CO₂, in cooling and refrigeration systems. And this isn’t just in the EU but throughout the world as part of the existing Kigali Amendment to the Montreal Protocol, it said.

Variable frequency drives (VFDs), the company said, are playing an important role in reducing emissions and energy use in HVAC&R systems. Optidrive Coolvert, it said, is one of the smallest VFDs in its class providing OEMs with opportunities to reduce panel space and lower machine costs. It fits directly into refrigeration display cases alongside a CO₂ compressor, it added.

This is in addition to end-user savings of up to 25% using CO₂ refrigerant condensing systems, which it is specifically designed to work with, the company claimed. A combination of meeting EU F-Gas Regulations and cutting energy use is a significant benefit for the end-user as well as for the environment, it said.

Mike Carman, Head of Sales, Invertek Drives, said: “The recast of the F-Gas Regulation comes as the EU sets out its new and wider environmental ambitions through the Green Deal. It’s widely believed this is the precursor to a significant adjustment in the F-Gas Regulation timeframe.

“With either more cuts in the amount of HFCs available in the EU or increased limits on emissions, it’ll impact on the manufacturers and end-users of refrigeration and wider HVAC/R systems”

According to Invertek, the Optidrive Coolvert also has the widest ambient operating range of between -20 degrees C and +60 degrees C, making it ideal for use in a wide range of environments. It can be used for the control of CO₂ ­­­­rotary or scroll, BLDC compressors used in supermarkets and convenience store display cases; heat pumps, and condensing units, the company said. This is in comparison to the Optidrive Eco VFD, which operates on larger-capacity semi-hermetic and screw compressors used in industrial and food retail refrigeration racks, and chillers, the company added.

According to Invertek, Coolvert is compatible with all motor types, including induction motors, permanent magnet motors, brushless DC motors, synchronous reluctance motors and Line Start PM motors ranging between Single Phase (Active PSE) 7A and 20A, and Three-Phase 14A to 24A (input of 200V to 480V).

Its open Modbus RS485 communication, the company said, ensures seamless connection to any external application controller, allowing the OEM freedom to select which components to use, which again helps lower manufacturing costs.

With an IP20-rated front and an IP55-rated rear, its panel mounting allows the drive’s power electronics to be cooled by the chilled air of the condenser, the company said, adding that this allows OEMs to select the smallest panel size for the control of the electronics, while removing heat generated by the drive and maintaining the IP rating.