Ⅰ、Purpose and Service conditions

1. Purpose
This reduced -voltage auto-transformer( hereinafter referred to as auto-transformer) series is used for voltage reduction starting of squirrel-cage motor with three phase current AC.50~60HZ , in addition as the power 11-315KW auto-transformer must be isolated completely from the system when the starting is finished.
2. Service conditions
A height above sea-level not exceeding 1000m;
A temperature of ambient air not below -25℃ and not above +45℃ ;
Relative air humidity: ordinary type ≤85℃, damp and hot type ≤95℃;
In medium without risk of explosion and with too insufficient air and electric insulation dust to corrode metal and damage insulation;
In environment without water vapor and equipped with rainproof device.

Ⅱ、Structure

The auto-transformer is type of three phase star connection and air cooled;
The transformer has 60%, 80% rated
voltage ratio tapping, and the obvious
voltage percentage sign is existed
at the tapping.

Ⅲ、Model and implication

1. Model and basic parameter


2. Basic parameters

Ⅳ、Dimensions and install size（Unit: mm）

Ⅴ、Important notice

1、When the starting motor is connected into 60% or 80% rated voltage tapping of transformer, the continuous loading time should not larger than 60 seconds.
2、Under the condition of typical 1 or more continuous loading, when the loading time of transformer reaches 60 seconds, then the interval cooling time of reloading should not less than 4 hours.

Note:
1、The dimension, install size and wiring method should be consulted with users when the capacity of reduced-voltage auto-transformer over 315KW. In case of starting time exceeds 60 seconds, it is confirmed by agreement between manufacturer and user.
2、If wiring on the top of transformer is required, the consumer need to consult with manufacturer.