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PROJECT
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10 000 litres of water. The treated water is supplied to a UV filtration plant on the property through a CM 5-3 pump from Grundfos. The entire filtration plant is not solar powered; however, it also currently uses 220V electricity from the building— which is planned to be converted in a future phase to utilise the excess energy created from the solar PV system. The pump supplies water to a twin pump set that pumps treated water to the building, which is then used for all applications required.
An additional pump is connected to the tanks that hold the untreated water. This particular pump directs water to the sprinklers only. The entire system is powered by eight 260W solar panels from Grundfos. Overall, the panels can generate up to 2 080W of power( 2kW at peak). The panels come with a 25-year warranty. Even on a cloudy day, the pump will continue to work because it derives power from the UV rays and not necessarily directly from the sun. Because of the pump’ s versatile motor, it can get power from different sources, including a generator, the sun, and single-phased power. The pump motor has an inverter built into it and can also operate on 12V or 220V AC or DC power.
The entire system includes a display that shows when the pump is in operation. This is able to pick up and create an alert on any problems with the pump. The display can be incorporated into a building management system so that it can be monitored regularly.
EMERGENCY AND BACKUP The system is connected to a 220V IO crossover switch. This switch can be used as backup in a situation where the system does not receive power from the solar system. Should there be a problem with the solar system, one would manually need to turn on the IO crossover switch, which would then revert to the municipal electricity 220V grid. The crossover does not happen automatically for this system; however, an automatic crossover switch is available.
A monitor that tracks the water level is installed in the system for situations where the borehole has insufficient water. If the water level falls below the level sensor, the pump will automatically cut out. At five-minute intervals, the pump will try to restart; however, should the water remain below the level sensor, the pump will not engage until the water level is at a satisfactory level. It is only then that the pump will automatically start operating again.
GRUNDFOS PRODUCT CENTRE AND PROJECT MATERIALS After drafting a design of the system, Rivers approached Grundfos for recommendations on the required materials
1. The filtration plant. 2. Pumps, UV, and RO filtration system.
3. Filtration system purifying 25 000 litres per day.
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www. plumbingafrica. co. za November 2017 Volume 23 I Number 9