New pump controllers complete upgrade for Queensland nursery

SNAPSHOT

• Logans Nursery, a Queensland-based wholesale nursery, has recently replaced its 12-year-old pump controllers with new models of the same brand
• Having a reliable system that delivers water every day at the correct pressure is crucial to the business, especially during hot summer weather
• The new controllers have eliminated pressure fluctuations and incorporate duty standby for every pump ensuring that a pump failure does not result in water not being delivered to plant stock when required

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Logans Nursery is a Queensland-based wholesale nursery business supplying plant stock ranging in size from revegetation tubestock to plants in 2000L containers. The business has two locations, a 2 ha site at Capalaba and a 110 ha at Donnybrook, north of Brisbane. Having a reliable and efficient irrigation system that can be operated at the flick of a switch is crucial to ensuring that plants are kept in top condition, especially during the heat of summer.

With the Lowara end-suction pumps at the nurseries having been replaced by multi-stage pumps three years ago, the control systems were the last pieces in the puzzle to be upgraded to ensure the irrigation systems apply water and use energy efficiently.

The decision to upgrade the pump controllers was made easy last year after one failed. This was no small task as the Donnybrook nursery had five units and the Capalaba nursery, two units.

Even application the key

The irrigation systems at the two sites, which apply water using both sprinklers and drip, are supplied from onsite storages, two at Donnybrook and one at Capalaba. The Donnybrook site has three Lowara e-SV pumps controlled by three Hydrovar variable-speed pump controllers at one dam and two pumps and Hydrovars at the other. Water use averages about 600,000 L a day. The Capalaba storage, which supplies an average of 160,000 L/day, has two pumps and two Hydrovars.

Darren Dodson from Total Water Services in Brisbane, a Brown Brothers Engineers dealer, has worked with Logans Nursery for more than 20 years designing, installing and upgrading the irrigation systems so is familiar with almost every piece of equipment at the two sites. He explained that a failure of one of the controllers last year prompted owner Graeme Logan to replace all seven as an efficiency measure.

“The controllers, which were about twelve years old and had each clocked up around 9000 hours a year, had certainly performed well but were definitely due for replacement,” said Darren.

A key requirement of any nursery irrigation system is to apply water so that all the plants in each zone receive the same amount at each irrigation, as a way of ensuring uniform plant growth.

Water pressure is a crucial factor in doing this. On the one hand, water applied at pressures that are too low to drive sprinklers at their designed application rates will lead to dry spots and underwatering. On the other hand, higher pressures can cause overwatering near the sprinkler head and create small droplets susceptible to wind drift and evaporation.

Pressure controllers such as the Hydrovar eliminate these pressure fluctuations and help maintain sprinkler pattern integrity and performance.

Solution provides backup protection

Darren said that the new Hydrovars had upgraded software and newer drives so were a good solution for the nursery.

“An important feature was that the system also has a backup on a backup, so there is duty standby for every pump.

“With the amount of stock in the nursery, not being able to supply irrigation water when required as the result of a pump failure would be a disaster,” said Darren.

This feature of duty standby, which originated in high rise buildings where reliable water supply is crucial, is becoming more common in nurseries, especially larger ones, as a risk management measure.

According to Darren, the installation of the new pump controllers was “very straightforward”, in part because the old equipment was being replaced by new, upgraded models of the same brand.

Wall-mounted custom booster controllers were configured to offer a wide range of flows providing flexibility based on pumping requirements at each location. They change motor speed, manage constant pressure or constant flow and vary pressure and flow to compensate for any system losses.

The upgrade has come at the right time for the Donnybrook site. Darren is now working on a 16 ha extension as water will be supplied to this extension using the current pump and controller system.

[Article originally appeared in the Irrigation Australia Journal]