135U3275 by Danfoss

The 135U3275 is a variable-frequency drive from Danfoss that belongs to the VLT FC 202 AQUA Drives series. It is intended for industrial automation tasks that require accurate speed control of three-phase induction motors. It is especially suited to pump and blower loops where regulating flow or pressure can reduce energy consumption and mechanical wear. By varying motor frequency instead of running equipment at full speed, the drive can match output more closely to process demand. That approach helps reduce abrupt starts and limit unnecessary mechanical wear.

This model delivers a continuous output current of 1.8 A and can supply up to 1.98 A for short-duration transients, giving headroom for startup surges. Its power section is sized for 0.55 kW motors, which corresponds to a stated mechanical rating of 0.75 HP. The drive accepts three-phase input between 380 – 480 VAC, and an internal RFI Class A1/B filter helps limit conducted emissions on that supply range. An IP55 enclosure protects the coated circuit boards against dust and low-pressure water jets, while standard cable entries simplify wiring through molded knockouts. Fieldbus connectivity is provided through a PROFIBUS DP MCA 101 A-option card, and a mains-disconnect switch is factory-mounted for isolation. Backup logic power is supplied by the MCB-107 24 V DC D-option module, so the graphical local control panel remains active during mains outages. This allows local status access to remain available during interruptions.

The housing has a mass of 7.96 kg. It measures 177 mm in depth, 200 mm in width, and 391 mm in height, allowing wall or panel mounting in compact pump stations. The compact enclosure also fits control panels where available mounting space is limited. Power losses are limited to 42 W at nominal load, so forced ventilation is usually unnecessary. Standard cable entries and coated boards support use in utility-grade water treatment environments.