Westek DPI25 Series voltage dip-proofing inverter

The DPI25 Series voltage dip-proofing inverter is designed for motor control applications where there are frequent voltage dips and momentary interruptions to power, and for instances where momentary interruptions to processes are expensive or where it is critical to maintain operations such as lifts or conveyors.

The DPI25 voltage dip-proofing inverters are essentially offline full-bridge IGBT inverters in series with the load and powered by an electrolytic capacitor that is normally kept fully charged via a static switch. When a voltage dip, momentary short-circuit or interruption occurs, the static switch opens and the inverter connects to the load. A timer controls the duration of operation of the inverter to disconnect power to the load if mains have not been restored within this period. When power is restored within the set time period, the inverter is first synchronised to the mains before handing control back to the static switch, thus avoiding voltage build-up on the load such as a relay coil and therefore assuring a smooth transition.

They are suitable for applications where constant voltage transformers would otherwise be installed, but with the difference that they will support the load even at zero mains voltage.

Models available cover 120 V and 208/230 V at 50/60 Hz. Timing for the inverter operation is adjustable in 100 ms intervals to a maximum of 3.1 s. Power factors of 0 to 1.0 are accommodated. There are a large number of models appropriate for coil ratings to 3000 VA available.