Rex Power Magnetics

65 Basaltic Rd. Concord, On L4K 1G4Canada

DRIVE ISOLATION TRANSFORMER

Product Overview & Application

Drive Isolation Transformers are designed for supplying power to SCR (Silicon Control Rectifier) motor drives which provide convenient variable speed motor control and can save on energy. Unfortunately, the drawback of these variable frequency drives (VFD) is that they produce harmonic voltage distortion and draw harmonic currents from the source which can be damaging both to the transformer supplying the power, and the other equipment that is connected to that supply.

A Drive Isolation Transformer (DIT) is designed specifically to supply power to VFDs. The isolation between the primary and secondary provides electrical isolation between the supply and the load. The transformer core is designed to handle the harmonic voltage without saturating, and the coils are braced to handle the mechanical forces that are introduced due to these harmonic currents. The coils are also designed to mitigate the impact of the harmonic currents. The winding conductors are selected and designed to keep eddy and stray losses to a minimum and the sufficient cooling is provided to dissipate the additional heat generated by the harmonic current.

Features & Benefits

Core and coil assemblies are mounted on neoprene isolation pads to reduce noise

Electrical Isolation between the supply and load minimizes feedback of noise generated by SCR voltage spikes to the supply.

Thermal sensors embedded in LV coil and wired to terminal blocks can be used for remote monitoring and protection. Bolted coil terminations suitable for copper or aluminum cables

Front & back covers are easily removable for service

Transformer core is constructed of high quality grain oriented silicon steel and operated well below the materials saturation levels in order to handle the impact of harmonic voltage and current.

Suitable for non-sinusoidal load currents with a K factor of 4 (higher K factors are optional).

Extra bracing is provided to withstand the mechanical stresses associated with SCR drives

Neutral terminal rated for 200% of line current rating to handle zero sequence harmonics flowing through the neutral.

NEMA 1 & 3R indoor (refer to catalogue for details) powder-coat drip-proof enclosure is standard. Weather shield kit is available for conversion to NEMA 3R outdoor.