Danfoss VLT® drives get bigger and smaller

Internal and external airflow options           High density installation

Danfoss High Power Range

Spectacular advances in drive efficiency and cooling techniques have enabled Danfoss to offer more compact air-cooled drives, right up to 1200kW.

Although Danfoss VLT® drives are now a market leading 98% efficient, that miniscule 2% loss still represents a fair amount of heat in larger drives. At 450kW, for instance, there is still 9kW of heat to be dissipated from within the drive and when there are a series of drives in a control room, heat is an issue that must be taken into consideration when planning the installation.

With advanced air-cooling techniques Danfoss has now expanded their VLT® range to a mighty 1200kW at voltages from 380V right through to 690V, enabling it to address the global market. Within the design of the drives, Danfoss has created a unique cooling channel at the rear of the drive that extracts 85% of the heat created and this can be channelled to the outside of the control room. This heat is isolated from the drive control circuitry resulting in extended drive life and higher reliability.

Improved drive efficiency has been a design goal for Danfoss and the current high efficiency of new drives has resulted from examining every element of heat production within the drive. Efficiency is an important factor in every component choice at the design stage and once heat loss within the drive has been minimised, innovative heat management techniques have been adopted to direct most of the heat away from the control section of the drive. High efficiency power transistors are mounted on thermally efficient heat sinks, copper in some instances, with the heat sink fins mounted into a cooling duct at the rear of the drive. Cool air can be drawn from and exhausted to the outside of the control room or even from outside of the building while intelligent design of the heat sink ribs ensures minimum retention of ambient pollutants.

Corrosion protection of the cooling circuits if available as an option to cope with harsh environmental conditions. To provide for where the customer requires conformity with standard industrial enclosures, Danfoss has developed the concept into an IP00 format that enables the drives to be mounted into standard industrial cabinets such as the Rittal TS8 series.

This high efficiency and intelligent heat management makes for very compact high power drives, enabling the drives to be mounted tightly side-by-side and consequently reduces the space required for installation. So although Danfoss’ drives have just got bigger, they’ve also just got smaller and cooler.

E-mail:- uk.drives.sales@danfoss.com
Web:- www.danfoss.co.uk/drives