MRO Magazine

Oil-free, variable speed, magnetic bearing centrifugal compressors

December 12, 2017 | By Rehana Begg

Tallahasee, Fla. – Danfoss, the world’s leading manufacturer of Danfoss Turbocor oil-free, variable speed, magnetic bearing centrifugal compressors, has added to its portfolio of low-GWP (global warming potential) compressors by introducing an option to use R-513A, and expanded its operating map range to cover low lift applications for the TT Series compressor family.

Danfoss Turbocor compressors are engineered and manufactured in Tallahassee and deployed around the world to help buildings reduce energy consumption and costs.

New low-GWP refrigerant option


R-513A is a low-GWP, non-flammable (A1) alternative refrigerant to R-134a that allows chiller manufacturers to meet future HFC regulations, such as the European Union’s F-gas regulation. All Turbocor TT Series compressors produced starting in December 2017 with compressor firmware version 4.1 will be compatible with both R-134a and R-513A. Existing Turbocor TT Series compressor revision F models using R-134a can be retrofitted to use R-513A by simply changing the electronic controllers.

This new refrigerant option broadens Danfoss’ comprehensive portfolio of Turbocor compressors using low-GWP refrigerants. In addition to the TT Series compressors, Danfoss already offers the Turbocor TG Series compressors that use ultra-low-GWP refrigerant HFO-1234ze. Similar to R-513A, HFO-1234ze allows chiller manufacturers to be in compliance with upcoming refrigerant regulations that restrict the use of HFC refrigerants.

In summary, the following Danfoss Turbocor compressors now use low-GWP refrigerants:

  • Available with HFO-1234ze: Danfoss Turbocor TG Series Compressors – 40 to 150 tons
  • Available with R134a and R513A: Danfoss Turbocor TT Series Compressors – 60 to 200 tons

New low lift capabilities

Danfoss also has expanded the operating range of its Turbocor TT Series compressors to support low lift applications such as air-cooled heat pumps — enabling chiller manufacturers to expand their product offering to cover even more air-conditioning and process applications. The low lift operating range allows chillers to start and operate at low condenser water temperatures that are common during cold ambient temperature conditions and gives manufacturers the flexibility to eliminate the use of expensive economizers on chillers.

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