Specification for GRUNDFOS dedicated controls
Requirements
The wastewater pumping station controller must as a minimum meet the following specifications; have a large minimum 3.54 x 4.72 in (min. 90 x 120 mm) graphical display for easy overview and operation, have easy to operate large keys, allow for easy setup and commissioning with start-up wizard and allow for free selection on language in the menu. It must be possible to activate all functionality without any programming, operate pumps direct on line, via soft starter, auto transformer or variable speed drive, allow for duty/standby and parallel operation of up to six pumps with any motor sizes, allow up to nine digital and five analogue inputs from sensors with voltage 1 – 10 V or current (0 – 20 mA, 4 – 20 mA), allow level control by means of either level switches or an analogue pressure or ultrasonic level sensor or a combination of digital and analogue sensors.
Control design
The Grundfos Dedicated Controller has been designed specifically for controlling one to six pumps in wastewater pumping stations. The large, highly intuitive, graphical user interface and the vast range of functionalities in the controller makes it very user friendly and flexible. The Dedicated Controller can also be integrated to most SCADA systems via a range of different communication protocoloptions.
Control construction
The controller must be built into either a powder coated steel cabinet for indoor use or a stainless steel cabinet for out-doors use. The control cabinet shall be fully documented with wiring diagrams and operating manuals.
The controls cabinet shall include an external visual alarm light.
The controller shall also be able to provide the following functionality; start level variation (reduced sedimentation), daily emptying and foam draining, anti-clogging, safety after-run delay, control mixer, pump flow calculation, and system flow calculation.
Controller specifications
The wastewater pumping station controller shall as a minimum meet the following specifications; allow connection of analogue water in oil sensor, allow surveillance and handling of alarm conditions of PT100 or PT1000 sensors in pump bearings and/or windings, it shall be possible to set start and stop delays in the controller, allow integration to Scada system via Modbus RTU/TCP IP or radio modem via RS-485 and be able to send SMS messages to up to three different numbers in event of alarm. The use of the different numbers must be selectable via a scheduler function.
Ensure tripping or warning in case of: Overload, under load, high motor temperature, over voltage, under voltage, power factor, current unbalance and loss of communication.
It must be possible to operate the connected pumps in two logically different groups and to alternate between the groups
The controller shall provide data logging such as alarms, runtime, flow, overflow, volume, energy, etc
The controller shall provide an electrical overview of all in – and outputs for service and maintains people.
The controller shall provide interlocking functionality so that if a pumping station is full shall the previous pumping station in the network delay start of pumps and thereby utilize the storage capacity of the entire network and avoid overflowing
Controller specifications for VFD operated pumps
The controller shall in addition include the following functionality for VFD operated pumps: anti-clogging (**), automatic energy optimization (*), specific energy test, output frequency, monitoring of voltage, monitoring of current, monitoring of phase sequence, monitoring of power, monitoring of energy, monitoring of torque, reverse start, run flush, and stop flush.
Controlled energy consumption
(*) Automatically optimized energy operation:
To ensure the lowest possible specific energy consumption kWh/m3, the controller shallcontinuously learn and adapt to duty conditions in the specific pumping system. The controller shallimmediately adapt pump speed in response to data from the frequency drive and a flowmeter. Specific energy consumption can also be provided by an electronic motor protection. This gives a continuous overview of pumping efficiency, enabling timely service and maintenance of pumps and mains.
Controller anti-blocking function
(**) Anti-blocking function:
To prevent clogging caused by the increasing amounts of the fibrous component and solids in sewage today the controller shall be able to “Flush or reverse” the sewage pumps.
This anti-clogging function must act on any abnormal events to stop pumps from clogging.
Parameters to be monitored: Monitoring of the power factor, monitoring of current, monitoring of power, monitoring of low flow via flow meter, and monitoring of over temperature (via pt 100/1000).
Date: 2011-11-11
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