High quality and safety three phase dry autotransformer is 25 kVA power rating, 50/60 Hz rated frequency, step down input voltage 380V AC to output voltage 220V/200V. Winding material copper or aluminum is available, other primary and secondary voltages can be customized.

Applications: The 3-phase autotransformer can be used in CNC production equipment, SMT, printing machines, electrical discharge machines, automatic plug-in machines, precision measuring equipment, laser cutting machines, plastic molding machines, medical monitoring systems, PCB drilling machines, laboratory equipment, military use Instrumentation control center, etc.

Specification

Features

• 3-phase autotransformer has enough power, the wiring is tight and neat, and does not skip turns. Coils adopt insulated H-class enameled wire, with low no-load current and low loss.
• The 25 kVA dry-type autotransformer has built-in silicon steel sheet, which has good magnetic flux performance, high heat dissipation coefficient and low magnetic loss.
• The autotransformer uses electrophoresis technology clamps, no burrs on the edges, rounded corners to prevent collisions, and not easy to corrode.
• Tinned copper tube terminals and rail-type wiring ports are convenient for wiring and ensure that the power-on overload capacity is increased to the extreme.

25 kVA 3-Phase Autotransformer Schematic Wiring Diagram

Tips: Step-down starting of the 3-phase autotransformer.

The step-down starting of the 3-phase autotransformer refers to the use of 3-phase autotransformer to reduce the starting voltage applied to the stator winding of motor when the motor starts. After the motor is started, the motor is separated from 3-phase autotransformer to operate normally under full voltage. With 3-phase autotransformer step-down starting, the starting current and starting torque of the motor are reduced in proportion to the square of the terminal voltage. Under the same starting current, larger starting torque can be obtained.

3-phase self-coupling step-down starting circuit cannot be operated frequently. If the start is unsuccessful, the second start should be more than a few minutes apart. After two consecutive starts, the operation should be restarted at least half an hour later. This is to prevent the starting current in the windings of 3-phase autotransformer from heating up and damaging the insulation of the autotransformer.