As dairy conversions spread across the New Zealand countryside, the irrigation of pasture is increasing. Robindale Dairy Farm in Canterbury is one of many sites using AuCom soft starters to ensure optimal operation of their irrigation system.
Robindale operates two giant centre pivot irrigators, each covering a 1.8 kilometre circle of prime pasture and taking 32 hours to complete one circuit. The irrigation system is fed by two bores which draw water from 160 metres underground, using 230 kW submersible pumps.
When an irrigator is started, a soft starter activates the first 230 kW pump and water starts to fill the mainline and pivot. After 5 minutes the second pump, 1000 metres away, also starts, helping to fill the mainline and build system pressure. Both pumps are soft-started using AuCom's advanced Torque Control feature, which minimises pressure surges during starting. This ensures a smoother, more linear acceleration to full speed.
The system was designed and commissioned by Gary Roxburgh of Nairn Electrical. Gary has installed hundreds of soft starters into irrigation systems since 1991, and he prefers to use AuCom products because of the advanced features which ensure safe and trouble-free operation of the system.
Robindale is one of New Zealand's largest dairy farms, and demands the highest standards of reliability. "With pumps of this size it was important to get it right," says Gary. "We needed a tailored solution from a company with a commitment to back-up and service. The AuCom starters give us all the benefits of using motor controls from a specialist in the field."