Tramo ETV manufactures world-class Transformers
A Qualified Supplier of Transformers
At TRAMO ETV, we specialize in the manufacture and delivery of transformers and inductors for marine and heavy industries, as well as various special applications. Our product range of low-voltage transformers is very extensive, ranging from 15 VA to 200 kVA.
We also offer a wide range of accessories that can be included such as pre-magnetization systems, fan motor starter units, or additional windings for auxiliary power.
TRAMO ETV’s transformers are always manufactured and delivered ready for direct installation and use. All our transformers are built according to SS-EN IEC 60076-11.
We Manufacture the Following Types of Transformers
- Variable Frequency Transformers
- Autotransformers
- Step-down Transformers
- Full Transformers
- Isolation Transformers
- Safety Transformers
- Insulation Transformers
- Measurement Transformers (current and voltage transformers)
- TRAMO ETV Product Names: OFS/OFL, VF/GF, TOFS/TOFL, TVF/TGF, FTPK/TFTPK, OFB, OFU, OFK
Typical Applications
- Small transformers: signal systems, amplifiers, home electronics, etc.
- Medium-sized transformers: laboratory equipment (with very specific requirements), machine tools, control cabinets, control and regulation equipment, UPS, adaptation transformers, etc.
- Large power transformers in the power grid: distribution transformers, power stations, industry adaptation transformers, isolation transformers for marine shore connections, local transformers (along railways), etc.
Voltage Transformers
Measurement Transformers
A measurement transformer, also known as an instrument transformer, is an electrical device used to measure high voltages or currents and convert them to a proportional and manageable level for monitoring and measurement. They are typically used in electrical distribution systems and also in industrial facilities to ensure safe and accurate current and voltage measurements.
Measurement transformers are essential components for ensuring accurate measurements. They allow for the use of properly sized and sensitive measuring instruments while providing complete isolation and protection against dangerous current levels.
Trafo Guide
Considerations When Sizing a Transformer for Your Application
Sizing a transformer can be quite complex. Therefore, we at TRAMO ETV have compiled this TRAFO guide to step-by-step help you consider what to think about when sizing a transformer for a specific type of application.
Basic Data (primary/secondary voltage and load effect)
- The number of primary and secondary voltages required for my application (there can be multiple per transformer)
- Primary Voltage (actual voltages over a transformer's primary winding)
- Secondary Voltage (actual voltages over a transformer's secondary winding)
Operating Conditions
The temperature in the windings is crucial for how much a transformer can be loaded. Therefore, how well heat can be dissipated is important. In intermittent (alternating) operation, with the same load, the temperature does not reach as high as in continuous operation. If the time the transformer is loaded is small compared to the time it is unloaded, the temperature increase will be moderate compared to the increase under continuous load. Due to thermal inertia, the emitted heat remains constant, and a larger part of the stored heat is released, lowering the temperature. This allows the transformer to be temporarily overloaded.
If you have a high proportion of frequency-controlled applications, such as frequency converters (drives or motor control), these can generate harmonics that lead to losses and thus affect how the transformer should be designed. Therefore, it is important to inform the supplier about this.
Ambient Temperature (Load)
A transformer's rated power is specified at maximum ambient temperature. If the ambient temperature is higher, the load must be reduced. Conversely, the load can be slightly increased at lower temperatures. Therefore, it is important to consider how the transformer is mounted, for example, if it is connected to heat-emitting components or placed with access to good ventilation.
Cooling
To achieve effective heat dissipation and reduced losses, the transformer's enclosure and cooling system should be designed to divert as much heat as possible from the transformer. The enclosure can be adapted to include cooling air circulation, or it can be equipped with forced cooling where fans are used to lower the surrounding temperature. An important question to ask is:
How tight must the enclosure be to meet the requirements from the intended environment? The tighter the enclosure, the poorer the cooling, which affects the size of the chosen transformer.
- Examples of common enclosure classes: IP20, IP23, IP54
- Learn more about IP enclosure classes here >>> >>>
Voltage Drop
Small transformers have significantly greater voltage drops than large transformers. When loading smaller transformers, both primary and secondary currents become significant, and the smaller a transformer is, the more attention must be paid to the voltage drop. This can often be complicated, and our tip is to discuss this with your supplier.
Losses
It's good to know that all types of transformers incur losses. There are primarily two main types of losses to consider:
- No-load losses: magnetization losses, which occur when the iron in the magnetic circuit is exposed to an alternating magnetic field. These losses can be considered constant when the transformer is voltage-applied.
- Load losses: consist of current heat losses that occur when current flows through a resistance in the windings, and additional losses due to leakage fields around the windings. Load losses change proportionally with the square of the load.
Regardless of the type of loss generated by the transformer, it's good to be aware of how these losses affect the ambient temperature. Try to place the transformer in spaces where it affects the environment as little as possible.