page 3 of 3 2007.12.06

Saving Energy, Improving the Product

Inverter technology
Danfoss offers the VLT6000 HVAC series of frequency converters specifically designed for the speed control of centrifugal pumps and fans.
Installation of an inverter will allow the user to make major energy savings and will make the control of the system more efficient and more readily adaptable to new demands that may be placed on the system in terms of flow or pressure.
The instrument has numerous functions and can be fully integrated with the Building Management Systems.
The power ranges from 1.1 to 450 kW, whereas the electrical supply can be 3 x 220-240 V or 3 x 380-460 V. The protection classifications are IP00, IP20 and IP54.
The inverters have RFI filters in conformity with the EN55011-1A regulation (relating to industrial settings) on shielded motor cables up to 150 m, and with the EN55011-1B regulation (relating to residential settings) on shielded motor cables up to 50 m.
There is also inductance in the intermediate circuit, in order to restrict the harmonic distortion in the grid.
The PID controller incorporates two comparative algorithms on two feedback voltage signals (current or pulse signals.)
Among the various features included, there is the AEO (Automatic Energy Optimisation) function, the Sleep Mode function, for systems with protracted idle times, and the internal Real Clock Time function, for the definition of given actions that present set sequences.
The Johnson Controls, Landis/Staefa and Modbus RTU protocols are all integrated, whereas the Profibus, LonWorks and DeviceNET protocols are optional.
Using the optional Cascade Controller board it is possible to manage up to 5 pumps or fans, with the possibility of alternating the pump/fan under the control of the inverter.