Isolation Transformer, Autotransformer. Series PDU and PSU provides flexibility. Dual Primary And Secondaries. All Windings Rated 0/104/110/120VAC for PDU series. The PSU Series The Secondary Rated At 0/208/220/240V. Nominal Operation 110 To 110 Volts, 220 To 220 Volts, 110 To 220 Volts Or 220 To 110 Volts. Can Be Operated As An Autotransformer By Connecting A Primary Group In Series With A Secondary Group, Which Permits Nominal Operation At 440 To 220 Or 220 To 440 Volts.