Irrigation and Farm Generator Power: Seasonal Duty and Off-Grid Sizing

Most farms and irrigation schemes need a set that runs hard for a season, then sits, on a site with no grid and a big pump motor to start. Size on the pump starting kVA plus the running load, plan for dust and weather, and keep the set in the lower to mid bands where most single pivots sit. Start from the diesel range and confirm the derating before you commit a site.

Four constraints a farm and irrigation set faces

A farm set earns its keep in bursts and in hostile conditions. Four constraints decide the build more than the nameplate.

• Seasonal duty. The set may run 18 hours a day for six weeks at irrigation peak, then idle for months. Specify prime or continuous duty for the season, not a standby rating that assumes a few hundred hours a year.
• No grid, long cable. Many irrigation and remote farm sites have no utility supply, so the set is the only power. Cable runs are long and the pump motor start is the event that decides the alternator.
• Pump motor start. A centrifugal or submersible pump draws a hard starting current that can be several times the running load. The alternator and AVR must hold voltage through it, or the pump never reaches speed.
• Dust, weather and critters. Open fields mean dust, rain, vermin and tractor traffic. A weather-sealed, elevated, lockable set outlasts an open skid left in the field.

Sizing step by step

Work the pump first, then the rest, then the site. Do not size from the connected load and hope the motor starts.

1. 1List the pump and the auxiliaries. Pump running kW, the start method (DOL, star-delta, soft start), plus lighting, control and any dairy or cold load.
2. 2Add the starting kVA. The pump start usually sets the engine and alternator size, often well above the running total. State the start method in the enquiry so the AVR is sized for it.
3. 3Add the seasonal peak. Grain drying or a second pivot in peak season adds load on top of irrigation; size for the worst week, not the average day.
4. 4Apply the site. Open, often hot or high sites cut output as everywhere else. Use the same planning factors and link the derating to the derating worked example when the farm sits above 1,500 m.
5. 5Pick the band and the form. Choose the open or weatherproof build in the band that covers the derated figure with margin, and keep it elevated and serviceable in the field.

Farm load and the band it lands in

These are planning positions, not a substitute for the load list. They show where each kind of farm duty usually falls in the range.

Which build suits a farm site

For a set in a field, the enclosure and the start gear matter as much as the kW. KINBOOST builds weatherproof, elevated and auto-starting sets with pump-friendly alternators, because that is what an irrigation duty demands. See the farm and agriculture solutions page for the line-up.

• Weatherproof canopy or open skid on a skid base. Choose the enclosure for the season and the site; an open skid only where attended and sheltered.
• Pump-rated alternator and soft start. Size the alternator for the pump start and use a soft starter where the cable or the supply is weak.
• Elevated, drainable base. Keep the set clear of mud, vermin and flood, with a base tank sized for the irrigation shift.
• Auto-start for the season. A set that starts on demand and runs unattended through the watering window saves the labour the duty is meant to free up.

Questions buyers ask about farm sets