DWLS stormwater transfer pump station
At GPM
Generator Property Management (GPM) runs a dirty water lift station at a remote site. Stormwater from around 40 acres drains into an underground reservoir. When it fills, an 80 kW submersible pump transfers the water to an 8 ML dam with an oil separator. There is no mains power, so the pump runs from a diesel generator.
Challenges
Off-grid site
No 415 V supply at the site. The pump runs from a diesel generator.
Overloads on pump starts
The generator and alternator overloaded on direct-on-line starts.
Routine site visits
With no telemetry, technicians drove out to check the pump by hand.
Solution
Solar and generator
The control system runs on its own at a site with no mains power. The diesel generator starts automatically and powers the pump when the well reaches high level. While the generator is off, solar panels charge a 12V battery that keeps the controls and the health monitoring running through the night and on cloudy days.
Variable speed drive
A 90 kW variable speed drive (VSD) takes the load off the generator at pump start. It limits the starting current and ramps the pump up gradually. The VSD starts automatically on high level, or on a local or remote request from the controller, and adds motor protection for the pump.
Remote monitoring
A web page controls and monitors the station: pump state, active and past alarms, fuel level and battery level. To save power the site controller sleeps between checks, but a pump run can still be requested from the web page, and the system starts the pump at its next wake cycle.
Results
Lower running costs
Fewer site visits, so less travel and labour.
Solar and sleep mode cut generator run time and fuel.
Smoother starts mean less wear on the pump and the generator.
Monitoring on solar power
Pump state, fuel level and alarms are visible all the time, so problems are picked up before an overflow.
The controls and monitoring run on solar while the generator is off.
More uptime
The VSD limits the starting current, so the generator no longer overloads.
The pump ramps up gradually, which reduces mechanical stress.