Technical Support
Phase Converter for Pivot Irrigation
Phase Converter for Pivot Irrigation
Center pivot and linear irrigation systems rely on three-phase power to run their drive motors efficiently across long spans. In rural agricultural areas, three-phase utility service is often unavailable or prohibitively expensive to bring to a field. A rotary phase converter—or a set of them—is the standard, proven solution for powering pivots on single-phase service.
How to Size a Phase Converter for Irrigation Pivots
Sizing depends on how many pivots start at the same time versus how many run simultaneously:
If Multiple Pivots Start at the Same Time
Sizing Formula: Total HP of All Pivots Starting Simultaneously × 2 = Phase Converter Size
If More Pivots Run Than Start at Once
Running Load Formula: Total Running HP × 1 = Additional Converter Capacity Needed
In practice, if you stagger pivot starts, you may be able to use a smaller converter and sequence the startups. We can walk through your operation to find the most cost-effective configuration.
Voltage: 460V Is Common in Agriculture
Many irrigation pivot motors are wound for 460V three-phase operation, especially on larger systems. Single-phase utility service in rural areas typically comes in at 240V. If your pivots are 460V, you will need the NLT model—which includes a built-in step-up transformer to convert your single-phase 240V to 460V three-phase.
Confirm the motor voltage on the pivot’s motor nameplate or with the pivot manufacturer before ordering.
Typical Sizing Examples
- Two 5 HP pivots starting together: 10 HP total × 2 = GP20NL or GP20NLT
- One 10 HP pivot: 10 × 2 = GP20NL or GP20NLT
- Three 7.5 HP pivots starting together: 22.5 HP × 2 = GP50NL or GP50NLT
Installation in the Field
Phoenix GP series converters are housed in NEMA-rated enclosures suitable for agricultural environments. They are designed for unattended, remote operation—which is exactly what irrigation applications require. Many farmers mount them in a weatherproof electrical shed near the service point.
What to Tell Us When You Call
- Number of pivots and HP of each drive motor
- Whether pivots start simultaneously or are sequenced
- Motor voltage (230V or 460V three-phase)
- Single-phase service voltage and amperage available at the site
📞 800-417-6568 — We have helped farms across the country solve their irrigation power challenges.
Talk to a Phase Converter Engineer
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