Agricultural Irrigation: Remote Pump Station Design

Project Overview

A 500-acre almond orchard in California's Central Valley required a complete irrigation system upgrade. The operation included four deep well pumps ranging from 50HP to 100HP, positioned at distances from 800 to 2,000 feet from the utility service entrance. The existing electrical infrastructure, installed decades earlier, had become increasingly problematic as the operation expanded and pump sizes increased.

Agricultural electrical systems present unique challenges because of the distances involved. Unlike urban or suburban installations where most loads are within 200 feet of the electrical service, farm equipment is often located at the far reaches of the property. Well pumps, grain handling equipment, and irrigation systems may be 1,000 feet or more from the main electrical panel. At these distances, even modest loads can experience significant voltage drop if conductors are not properly sized.

The farm had experienced persistent problems including premature motor failures, reduced pump efficiency, and high energy bills. An engineering assessment revealed that the root cause was excessive voltage drop in the original 240V single-phase distribution system. This case study documents the solution that transformed the irrigation system's performance and reliability.

The Challenge: Long-Distance Power Distribution

The voltage drop at the farthest pump exceeded 11%, meaning the motor received only 213V instead of the rated 240V. At this reduced voltage, the motor drew significantly higher current to produce the required power, leading to overheating, reduced efficiency, and shortened lifespan. The pump at Well #4 had required motor replacement three times in five years.

The Solution: 480V Three-Phase Distribution

The engineering solution leveraged a fundamental principle of electrical distribution: higher voltage means lower current for the same power. By converting to a 480V three-phase distribution system, current would be reduced by approximately 75% compared to the 240V single-phase system, dramatically reducing voltage drop.

Results and Economic Benefits

Plan Your Agricultural System

Planning an irrigation system or remote agricultural load? Our voltage drop calculator helps you evaluate different voltage levels and conductor options for optimal performance.