5Variable Transformer
The variable transformer is a special type transformer whereby its turn ratio or voltage ratio can be varied or adjusted either by hand or by motorized control. Thus, the output voltage of the transformer is varied to the required voltage according to the loading requirements.
There are 2 types of variable transformer:
A: Slide type variable transformer
B: Variable induction transformer
Slide Type Variable Transformer
| Capacity | 0.3 to 1,000kVA |
| Number of Phase | 1 Phase or 3 Phase |
| Operating Frequency | 40 to 60, 50, 60, 50 & 60, 100, 120, 200, 240, 400, 500 Hz |
| Input Voltage | 100, 115, 200, 220, 230, 240, 380, 400, 415, 440, 460, 480V |
| Output Voltage | 0 to 130V, 0 to 260V, 0 to 300V, 0 to 450V, 0 to 750V |
| Control | Manual adjustment by hand knob or steering wheel Push-button adjustment by electrical servo induction motor |
| Readings | Scale or marking on plate Voltmeter and ammeter |
| Termination | binding post, heavy duty terminal block or tin-plated copper bus-bar terminals |
| Enclosure | Rugged steel enclosure with powder coated finishing or paint finishing for indoor use |
Variable induction transformer
| Capacity | 50 to 5,000kVA |
| Number of Phase | 1 Phase or 3 Phase |
| Operating Frequency | 50 or 60Hz |
| Input Voltage | 200 up to 22,000V |
| Output Voltage | 20 up to 22,000V |
| Control | Push-button adjustment by electrical servo induction motor |
| Readings | Voltmeter, Ammeter |
| Termination | Tin-plated copper bus-bar terminals or porcelain bushings |
| Enclosure | Rugged steel tank and cooling fins or radiators with multiple layers paint finishing suitable for indoor or outdoor use |
