TWA 251÷1501 TT/Y


_ktk_icon_versions_cooling_only.png _ktk_icon_compressor_turbocor.png _ktk_icon_axial_fan.png _ktk_icon_flooded_shell_and_tube.png _ktk_icon_microchannel.png _ktk_icon_gsm.png _icon_A_CLASS_2018_KTK_cooling.png _ktk_icon_refrigerant_R134a.png ktk_icon_refrigerant_R513A.png

The innovative TWA 251÷1501 TT/Y units, with R134a refrigerant, are designed to provide an effective solution to highly selective system needs. Efficiency at partial loads, low inrush currents, an excellent silent functioning, reduced weight and the specific design and handling of every manufacturing aspect make the series the top unit of the range.
The use of TURBOCOR dynamic partial-load oil-free magnetic levitation compressors managed by the TURBOSOFT self-adaptive electronic control, of flooded shell and tube evaporator and innovative heat exchangers, traditional or Microchannel, results in a high energy efficiency with unequaled SEER values, with minimum water content, and an excellent silent functioning. Compared to traditional units, equipped with Screw compressors, TURBOLINE units have low operational costs during their entire operating period, even lower than 50%.
Are available as option the new EC Inverter fans with high available static pressure and efficiency.
The units are compliant to the 2021 ErP Regulation.
On request, units can be supplied with R513A refrigerant.


  • TWA - Cooling only
  • TWA/MC - Cooling only with MICROCHANNEL coils

Power range

  • 248-1456 kW
  • 71.0-414 Ton


  • Structure with supporting frame, made of galvanised sheet metal with additional protection provided by polyester powder coating.
  • Semi-hermetic centrifugal compressors with dual Turbocor turbine, oil free, magnetic rising rotor, thermal protection, continuous capacity adjustment system thanks to built-in INVERTER, automatic anti-cavitation system. The power circuit of the compressor is fitted with a set of electrolytic condensers to control the rising in the event of a power failure, reactor for the power factor correction, EMI filter for electromagnetic compatibility.
  • Axial fans directly coupled to an electric motor with external rotor.
  • Condenser made of copper tube and aluminum finned coils or aluminium MICROCHANNEL coils.
  • High efficiency flooded shell and tube type evaporator, with one independent circuit on the refrigerant side and one on the water side, complete with water differential pressure switch.
  • Cooling circuit shut-off valves on suction, discharge and liquid line.
  • Electronic expansion valve.
  • Electronic high and low pressure gauges.
  • R134a refrigerant. On request R513A refrigerant.
  • Electrical board includes: main on-off switch with door lock, fuses, electronic/digital overload device to protect the compressors and thermocontacts for fans, interface relay and terminals for external connections.
  • Condensing Control is included: electronic proportional device that ensures efficient and continuous functioning of the unit with outside air temperature down to –20 °C. It also allows to reduce the sound level especially at night. It consists of a fans speed controller with continuous speed regulation, high and low pressure transducers on cooling circuit and an electrical heater on electrical board.
  • TURBOSOFT control and regulation system, equipped with RS485 serial interface, can be supplied with an optional Web Monitoring device for remote monitoring via GPRS/EDGE/3G/TCP-IP network.

Factory fitted accessories

  • IM Automatic circuit breakers
  • EC EC Inverter fans
  • ECH EC Inverter fans with high available static pressure
  • TX Coil with pre-coated fins
  • TXB Coil with epoxy treatment
  • EW External water connections
  • PU Single circulating pump
  • PD Double circulating pump
  • FE Antifreeze heater for evaporator
  • FX Antifreeze heater for evaporator and pipes
  • FZ Antifreeze heater for evaporator, single pump and pipes
  • FH Antifreeze heater for evaporator, double pump and pipes
  • TS Touch Screen Interface
  • WM Web Monitoring - Wireless remote monitoring (GPRS/EDGE/3G/TCP-IP)
  • IST Modbus TCP/IP protocol, Ethernet port
  • ISB BACnet MSTP protocol, RS485 serial interface
  • ISBT BACnet IP protocol, Ethernet port
  • ISL LonWorks protocol, FTT-10 serial interface
  • ISS SNMP protocol, Ethernet port
  • IAV Remote set-point, 0-10 V signal
  • IAA Remote set-point, 4-20 mA signal
  • IAS Remote signal for second set-point activation
  • IDL Demand limit from digital input
  • CP Potential free contacts

Loose accessories

  • MN High and low pressure gauges
  • CR Remote control panel
  • RP Coils protection metallic guards
  • FP Coils protection metallic guards with filter
  • AG Rubber shock absorbers
  • AM Spring shock absorbers
  • FL Flow switch
Cooling STD versionCooling capacity (1)kW248282335627770929107512601456509403
Absorbed power (1)kW738197185221274311362433145116
EER (1)3,403,483,453,393,483,393,463,483,363,513,47
Cooling STD version (EN14511)Cooling capacity (1)kW247281334624767925107212561450507402
Absorbed power (1)kW748298188224278315366439147117
EER (1)3,323,433,403,333,433,323,413,433,313,463,42
SEER (2)4,885,065,075,165,345,295,365,405,255,145,18
Energy Efficiency (2)%192199200203211209211213207203204
Cooling MC versionCooling capacity (1)kW248282335627770929107512601456509403
Absorbed power (1)kW647386163198243281328381132106
EER (1)3,883,863,903,853,893,823,833,843,823,863,80
Cooling MC version (EN14511)Cooling capacity (1)kW248282335627770929107512601456509403
Absorbed power (1)kW647386163198243281328381132106
EER (1)3,883,863,903,853,893,823,833,843,823,863,80
SEER (2)4,935,115,125,225,405,345,415,465,315,195,23
Energy Efficiency (2)%194201202206213211213215209205206
Refrigerant circuits11111111111
Capacity stepsSteplessSteplessSteplessSteplessSteplessSteplessSteplessSteplessSteplessSteplessStepless
EvaporatorWater flowl/s11,8513,4716,0129,9636,7944,3951,3660,2069,5624,3219,25
Pressure dropskPa6440405646684650594435
Water connectionsDN100100100150150150150200200125125
Electrical characteristicsPower supplyV/Ph/Hz400/3/50400/3/50400/3/50400/3/50400/3/50400/3/50400/3/50400/3/50400/3/50400/3/50400/3/50
Max. running currentA1681681683375095177636581002329262
Max. starting currentA25252519428028853451577318633
Unit with pumpPump available static pressurekPa150200195145155120170220185175165
Water connectionsDN100100100150150150150200200125125
Sound pressureSTD version (3)dB(A)6969697070697071717069
MC version (3)dB(A)6868686969686970706968
WeightsTransport weightkg24402440277040204055571064607430764036852790
Operating weightkg25102510290041704225591066807660788038252920




  • 1 Chilled water from 12 to 7 °C, ambient air temperature 35 °C.
  • 2 Seasonal energy efficiency of cooling at low temperature. According to EU Regulation n. 2016/2281.
  • 3 Sound pressure level measured in free field conditions at 1 m from the unit. According to ISO 3744.
  • N.B. (1) Data of MC version are specified on technical brochure.