Autotransformers, due to their small dimensions and resin finishing technology, are usually used to start large squirrel-cage motors for ship’s tubular rudder  systems, amongst others.An autotransformer, during the activation of a squirrel-cage motor, lowers the voltage and the starting current, and also the starting torque, which results in a gentle start-up and lower losses in the motor circuit. The use of an autotransformer increases the mechanical durability of the driving mechanism and facilitates the selection of protective measures. The autotransformer start-up may be fully automatic through the use of appropriate connecting devices.

Manufacturing range:

Power range:  from 50 kVA up to 1000kVA
Voltage range: up to 36 kV
Isulation class: F or H
Type of cooling: AN, AF

Standard operating conditions:

Max. operating altitude – 1000 m above sea level
Operating temperature range – 25 to + 40 °C or other on request
Rated frequency 50 Hz (60 Hz on request)

Design characteristic:

Core– grain-oriented electrical steel sheets
assembled into core using the “Step-Lap” method
Winding  – electrolytic aluminium or copper wire or foil
Optional enclosure IP20, IP21,IP23,IP31,IP33,IP54

Standard equipment:

Thermal protection
PT100 or PTC Sensors
The terminals on the connectors HV
The terminals LV – busbar leadouts
Rating plate
Earting Terminals
Lifting lugs
Pulling lugs
Bi-directional wheels

Optional equipment:

Antivibration pads
Surge arresters
Earthing bolts
Cooling fans
Cable boxes
HV plug-in bushings

Making, testing & loss levels, tolerance ranges are in compliance with IEC 60076-1, IEC 60076-11