The VARIOspeed variable frequency drive (VFD), newly introduced by SJE-Rhombus, is designed specifically for pressure-control applications. As the flow and head conditions change in the pumping system, the VARIOspeed VFD is able to automatically control the pump speed and maintain a constant discharge pressure. The desired set pressure is set using the VFD keypad; the pressure transducer measures the pump discharge pressure. The VARIOspeed VFD is available from 5 HP to 150 HP at 208-240V, and 5 HP to 250 HP at 380-480V, single-phase or three-phase supply voltage. Typical applications include booster pumps, deep well submersible pumps and irrigation pumps.

SJE-Rhombus, Card No. 113