Auto-Transformers

Auto-Transformers

Auto-transformers are a single winding transformer, useful where isolation from the mains supply is not required.

SES can design & supply custom auto-transformers to importers of electrical equipment, or electrical contractors installing imported equipment.

SES can supply:

• Single Phase Auto-transformers
• Three Phase Auto-transformers
• Friendly Advice To Assist With Your Application

Advantages of SES Auto-transformers:

• Fast turnaround of custom transformers - often within days
• Robust construction
• Available as open type with flying leads or terminal blocks
• Choice of mounting brackets
• Terminal blocks or flying leads
• Tough Varnish Coating - either clear or black.
• Can be encased in powder coated steel (IP21) enclosure for hard wiring
• Insulation classes up to class H - 180Ã,°C
• Available in a wide power range - from 10VA to 500 KVA
• Australian Standard AS61558 - 1997 compliant

If you have electrical equipment from overseas that is designed to operate on a voltage different to Australian power (single phase 240v 50Hz, or three phase 415v 50Hz) we can help you with the correct auto-transformer.

Save yourself the expense of having imported electrical equipment rewound to operate from Australian power . A suitably rated auto-transformer can save you the expense of having equipment rewound, or having to buy an isolation transformer.

Auto-transformers are ideal for adapting imported equipment to Australian power (single phase 240v 50Hz, or three phase 415v 50Hz).

Auto-transformers are smaller, lighter & cheaper than isolation transformers of the same power.

For example, a three phase auto-transformer to power equipment rated at 200v 10KVA (imported from Japan) would be about half the size & weight of an equivalent isolation transformer.

Even greater savings can be achieved using an auto-transformer if the input & output voltages are closer together - e.g. single phase 240v / 220v or three phase 415v / 380v

Important Points To Consider With Auto-transformers :

1. Auto-transformers do not provide isolation from the electrical supply.
   
2. Auto-transformers are only suitable when the ratio of input/output is less than about half. Single phase 240v input / 100v are around the lowest viable output voltage.
   
3. Similarly, three phase 415v input / 200v output is about the lowest viable output voltage.
   
4. Auto-transformers can be used for step up as well as the more common step down applications.
   
5. There is always a common terminal in an Auto-transformer - this must always be connected to the neutral of the input supply (not the active).
   
6. Care should be taken to ensure that any imported equipment will operate at a power frequency of 50Hz. Some imported equipment (e.g. motors) may be rated at 60Hz only (as opposed to 50-60Hz) and may overheat if operated at 50Hz, even with the correct voltage applied.
   
7. Australian Standard AS 3000 - 1986 (Clause 4.28.4) requires that an auto-transformer that changes voltage by more than 25% must be an integral part of the equipment it is powering. This can be achieved by hard wiring the equipment to the output of the auto-transformer.

With our wide range of components & enclosures in stock, you can have a custom made auto-transformer designed specifically for your needs within days. Phone, fax or email your enquiry to us today - we may be able to help you even if you are unsure of the specifications required.

To Know More about Auto-transformers Please click here