Rotomax Center-Pivot Phase Converter

For Operating 460-500 Volt 3-Phase Center-Pivot Systems
 and Irrigation Pumps on Single Phase Electric Power

Three Things to Remember When You Buy Something for Your Farm:

ROTOMAX is the only Cast Iron Totally Enclosed Rotary Converter to pass US 508 Safety Tests. It features an Unconditional Lifetime Warranty against rotor failure, and all Models now include a Large Connection Box and Lightening Protection (see above) furnished with an Easy-Connect Terminal Block for your installer’s convenience.

ROTOMAX phase converters are Guaranteed Not To Stall when your pivot is started or reversed provided our sizing instructions are followed. When windshield-wiper type (reversing) pivots are operated, use the next size larger converter. For application instructions, see next page.

Center-pivots ride on large tires powered by small 3-phase electric gear motors. Unfortunately, most rural electric suppliers do not furnish 3-phase electricity to farms. The cost-efficient and dependable way to operate the pivot is with a ROTOMAX rotary phase converter. Center pivots operate on 480 volts 3-phase power. 480 volt single-phase is normally available from your local power company, and is easily processed into 480V 3-phase power through the ROTOMAX phase converter. If only 240 volt single-phase is available, a step-up transformer may be added to your installation

To size your Rotomax Phase Converter, add the total HP of pivot, pump, and end gun motors you wish to operate. Then look at the chart under "run HP" and find a model that fits your requirement. Be sure that no one motor in the system is larger than the "Start HP" rating of the model you choose.

Technical Information:

If your pivot operation is a "windshield wiper" configuration--that is, a pivot that runs a partial circle and then reverses direction--then you should choose one size larger than normal converter. Under normal pivot operation, only one-half the motors will start at once. However, when a pivot is reversed, all the motors that were "off" when stopped will now start. Thus, a 10 tower pivot may reverse, restarting 7 or 8 motors, and exceed the converter's normal "Start HP" capacity.

The converter should be mounted as close to the single phase service as possible to minimize the heavier single-phase wiring required. The 40 and 50 kVA Rotomax converters are available with an optional soft-starting feature that reduces the starting inrush of the rotary to approximately one-third of normal on start-up to prevent line disturbance.

All Rotomax converters are high-efficiency models. Power consumed by the converter will amount to approximately 5% of the operated load. (For every $100.00 of power required to operate the pivot, $5.00 worth is consumed by the converter.)

Smith Electric Motorworks / GWM Copyright 2007