The Danfoss VLT AQUA Drive is dedicated to water and wastewater applications. With a wide range of powerful standard and optional features, the drive is said to provide the lowest overall cost of ownership for water and wastewater applications. The full power range drive is available in the full power range from 370 W to 1,2 MW.
Auto tuning of the PI controllers
When enabling auto tuning of the PI controllers, the drive will enter Auto Tune Mode, where the drive for a short period of time operates in open loop with a constant speed. When the signal is stabilised at constant speed the drive will automatically change the speed, monitor the feedback reaction and in that way adjust the optimised settings for gain constant (P) and integral time (I). After setting the constants, the drive will automatically switch to closed loop and ensure optimised operation. The commission time is reduced and closed loop settings are optimised.
Pipe fill mode
The controlled filling of pipes prevents water hammer, water pipes bursting or sprinkler heads being blown off. This feature is useful in irrigation systems, water supply systems, etc.
The Pipe Fill feature in the new VLT AQUA Drive has two modes of operation. One for horizontal pipes where the system is operated with constant speed for a set time period and one for vertical pipes, where the system is operated in closed loop with a filling rate in units/sec.
End of pump curve detects breaks and leakage
The 'End of curve' function triggers an alarm, shuts off the pump, or performs another programmed action whenever a pump is found running at full speed without creating the desired pressure - a situation that can arise when a pipe breaks or leakage occurs.
Sleep mode
Sleep mode keeps pump wear and power consumption to an absolute minimum. In low flow situations, the pump will boost the system pressure and then enter sleep mode. Sleep mode in the new drive is based on speed and power. Monitoring the pressure, the VLT AQUA Drive will restart when the pressure falls below the required level.
Dry pump protection lowers maintenance costs
The VLT AQUA Drive constantly evaluates the condition of the pump, based on internal frequency/power measurements. In case of low power consumption at high speed - indicating a no-flow or low-flow situation - the VLT AQUA Drive can be programmed to stop.
Two-step ramps
Fast acceleration of the pumps to the minimum frequency, from where the normal ramp takes over. The feature prevents submersible borehole pumps from excessive wear and damage as they are brought up to minimum speed quickly. The final ramp takes over in a stop situation from min. speed to stop in order to quickly stop a submersible borehole pump to prevent damaging of the thrust bearings. Another ramp called check valve ramp can be enabled in, for instance, wastewater systems, etc, in order to ensure controlled closing of check valves.
Sensorless pressure or flow control
Sensorless pressure or flow control is a VLT feature that allows pump manufacturers to control the constant head (pressure) or flow levels without the use of sensors. The cost and time of installing, cabling and maintaining pressure and flow transducers are eliminated. Reliability also is increased, as no additional components or connections can cause malfunction.
Payback time indication
One of the major reasons for applying a VLT drive is the very short payback time due to energy savings. The VLT AQUA drive comes with a unique feature which continuously shows the remaining payback time for the investment. The user enters the specific energy price, the investment and the load profile for the application - the drive makes the calculation and provides the result. All this is easily done with the Danfoss Drives energy calculation PC software, VLT Energy Box.
Preventive maintenance function
20 preventive maintenance events can be scheduled based on the Real Time Clock, running hours or operating hours. Items can be user-defined words/messages, eg, 'Service pump'.
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