The AT Range covers auto starter transformers designed for reduced-voltage motor starting applications using the Korndörfer method.
Manufactured in the UK by Boardman Transformers, these units are suitable for industrial motor starting systems where controlled starting current and reliable transformer performance are required. The standard range is designed for 50/60Hz supplies, with common voltage taps of 50%, 65% and 80%. Other voltages and tapping arrangements are available on request.
Auto starter transformers for Korndorffer method of starting to BS4941 (EN 609470) for use on 50/60Hz supply.
Normal input voltage 380-415v with tappings of 50%, 65% and 80%. Rated for 15 starts per hour. Other voltages and tappings are available.
Key Features
- – Auto starter transformers for reduced-voltage motor starting
- – Designed for Korndörfer starting applications
- – Standard voltage taps of 50%, 65% and 80%
- – Other voltages and tapping arrangements available
- – Suitable for 50/60Hz supplies
- – Rated for 15 starts per hour
- – UK manufactured by Boardman Transformers
| Auto Starter Transformer | Auto Starter Transformer for reduced voltage starting of motors |
|---|---|
| Standard | BS4941, BSEN60947 |
| Input Voltages | Up to 1000V AC |
| Voltage Taps | 50%, 65%, 80% as standard – other taps available |
| Frequency | 50/60Hz |
| Insulation Class | F |
| Insulation Resistance | > 5 Meg Ω |
| Dielectric Strength | Winding to Earth > 2.5kV |
| Ambient Temperature | 40 |
| Duty Cycle | 15 Starts per hour |
| Part No. | kW | A | B | C | D | E | kg |
|---|---|---|---|---|---|---|---|
| AT1 | 15.0 | 240 | 120 | 220 | 170 | 80 | 14 |
| AT2 | 18.5 | 240 | 130 | 220 | 170 | 90 | 18 |
| AT3 | 22.0 | 300 | 140 | 300 | 220 | 100 | 28 |
| AT4 | 30.0 | 300 | 150 | 300 | 220 | 110 | 33 |
| AT5 | 37.0 | 300 | 160 | 300 | 220 | 120 | 39 |
| AT6 | 45.0 | 300 | 170 | 300 | 220 | 130 | 44 |
| AT7 | 55.0 | 360 | 200 | 360 | 320 | 100 | 48 |
| AT8 | 75.0 | 360 | 210 | 360 | 320 | 110 | 56 |
| AT9 | 90.0 | 360 | 220 | 360 | 320 | 120 | 64 |
| AT10 | 110.0 | 420 | 240 | 420 | 380 | 130 | 75 |
| AT11 | 132.0 | 420 | 250 | 420 | 380 | 140 | 86 |
| AT12 | 160.0 | 420 | 260 | 420 | 380 | 150 | 96 |
| AT13 | 200.0 | 480 | 300 | 500 | 440 | 160 | 120 |
| AT14 | 260.0 | 480 | 320 | 500 | 440 | 180 | 150 |
| AT15 | 300.0 | 480 | 330 | 500 | 440 | 190 | 170 |
| AT16 | 340.0 | 480 | 340 | 500 | 440 | 200 | 190 |
| AT17 | 400.0 | 600 | 300 | 600 | 540 | 185 | 220 |
| AT18 | 450.0 | 600 | 340 | 600 | 540 | 205 | 270 |
| AT19 | 550.0 | 600 | 340 | 600 | 540 | 225 | 320 |
Typical Applications
Auto starter transformers are commonly used where motors require a controlled reduced-voltage start rather than direct-on-line starting.
- – Industrial motor starting systems
- – Pumps and fans
- – Compressors
- – Production machinery
- – Plant equipment
- – Larger motor loads
- – Reduced-voltage starting applications
- – Industrial electrical control systems
Auto Starter Transformers and Auto Transformers
Auto starter transformers and auto transformers are related, but they are not used for the same purpose.
Auto starter transformers are designed specifically for reduced-voltage motor starting applications. They are used as part of a motor starting system to reduce the applied voltage during start-up.
Auto transformers are more general voltage conversion transformers used where voltage adjustment is required and full electrical isolation is not necessary.
For general single phase and three phase auto transformers, visit our Auto Transformers page.
For a wider overview of industrial transformer capability, visit our Industrial Transformers page.