Optimize comfort, reliability and energy efficiency
With multiple pump-dedicated control features, intelligent protection capability and sensorless pump control, Danfoss AC drives optimize comfort and energy efficiency and protect the drive, the motor and the equipment in the system. They also ensure optimized liquid supply in the event of leakage or a broken pipe. Dedicated features include:
Embedded multi-pump controller
The Pump Cascade Controller distributes operation hours evenly across all pumps. Wear and tear on individual pumps is therefore reduced to a minimum, extending their lifetime expectancy and reliability considerably.
Dry pump protection and end of curve detection
If the pump runs without creating the desired pressure, the drive sets off an alarm or performs another pre-programmed action. This happens, for example, when a well runs dry or a pipe leaks.
Auto tuning of PI controllers
Auto tuning enables the drive to monitor how the system reacts to corrections made by the drive constantly. The drive learns from it and calculates the P and I values, so precise and stable operation is restored quickly.
A pressure sensor mounted close to the pump provides a reference point that enables pressure to be kept constant at the discharge end of the system. The drive constantly adjusts the pressure reference to follow the system curve. This method both saves energy and reduces installation costs.
No/low flow detection and sleep mode
In situations with low or no flow, the drive enters sleep mode to conserve energy. When the pressure falls below the predefined set-point, the drive starts automatically. Compared to continuous operation, this method reduces energy costs and equipment wear and helps extend the lifetime of the application.
Pipe fill mode
Useful in all applications where controlled pipe filling is essential, such as water supply systems. Controlled (closed loop) filling of pipes prevents water hammering, bursting water pipes or blowing off sprinkler heads. Pipe fill mode can be used in both vertical and horizontal pipe systems.
The initial ramp provides fast acceleration of pumps to minimum speed, from where the normal ramp takes over. This prevents damage to the thrust bearings on the pump. The final ramp decelerates pumps from the minimum speed to stop.
The flow confirmation monitor protects equipment from unexpected flow stoppage. The monitor communicates on an ongoing basis with an external device such as a valve or flow switch. If the signal from the external device times out, the monitor trips the AC drive.
Some machines require lubrication of their mechanical parts before and during operation to prevent damage and reduce wear. During lubrication, certain equipment must remain active, for example exhaust fans. To achieve this, the Pre Lube feature supports a signal to an external device to perform a specific action for a user-defined time period. Configurations available: “Pre Lube Only”, “Pre & Running” and “Pre & Running & Post”.
Freely programmable texts
This function supports versatile adaptation to the application. Use freely programmable text messages, based on internal or external events, for information, warnings or alerts. The function also supports actions based on events, for example initiation of a ramp down triggered by a valve opening.
Advanced minimum speed monitor
Submersible pumps can suffer from insufficient cooling and lubrication when pump speed is too low. The advanced minimum speed monitor protects the pump by monitoring and adjusting the trip speed to reduce wear and tear. Downtime for maintenance is minimized, with no need for external monitoring equipment.
Check valve ramp
The check valve ramp prevents water hammering when stopping the pump, by ensuring slow pump speed ramp down just as the check valve ball is almost shut.
Sensorless pump control
Sensorless Control is a distribution pump control method which infers the average HVAC system heating or cooling demand from the hydraulic system resistance, and then adjusts the pump(s) speed to balance satisfying that demand with minimizing the energy used. Sensorless pump curves are embedded in the drive.
Reliability and Consistency Make Danfoss VFD's a Sure Bet in Las Vegas
For the mechanical systems that manage the indoor environment in this desert city, consistency and simplicity are desirable traits. Owners of casino hotels and restaurants that operate around-the-clock require HVAC equipment that is reliable and easy to operate and maintain.