The electrical machine is capable of galvanically separating two voltage levels safely without changing the frequency. The windings in a dry-type transformer are enclosed in air, resin, or completely sealed. They are not immersed or impregnated in liquids such as silicones, oils, or other materials.
These transformers can be used in various applications, including medium voltage auxiliary transformers for large electrical systems or plants, as well as supply transformers for shopping centers, schools, and institutions. Dry-type transformers do not contain moving parts and are therefore static machines. This helps extend their lifespan while reducing maintenance.
We must protect them to the maximum extent possible as they are an important part of any electrical system. We manufacture protection relays that specialize in dry-type transformers.
Relay for dry-type transformer: Maximize the “useful lifetime” and reduce power failures in your electrical system.
Dry-type transformers and oil-type transformers: Differences
There are two types of transformers:
Maintenance: Oil-type transformers require oil maintenance, while dry-type transformers require oil sampling but do not contain any oil.
Dry-type transformers are more energy-efficient, whereas oil transformers have a longer lifespan.
Energy Costs: The energy costs of dry-type transformers are higher than those of oil-type transformers.
Noise: Oil-type transformers are quieter.
Recyclability: Metal/copper is easier to recycle than oil transformers.
Dry transformers have lower voltage capabilities than oil-types. Oil transformers can handle heavier loads at higher voltages.
Location safety: Dry-type transformers are used in buildings because they are environmentally safer and less flammable, making them ideal for shopping malls, hospitals, and residential complexes. Outdoor installations usually employ oil transformers due to the higher risk of fire and oil leakage. However, these units are also more environmentally friendly.
Checklist for preventive maintenance of dry-type transformers
Remove dust, dirt, and condensation from the HV and LW windings. Vacuum the transformer to prevent dirt and dust from dispersing.
- Check windows for damage and clean the room.
- Inspect the roof of your room for any water infiltration.
- Check the temperature of coils under normal conditions.
- Ensure that cables and busbars have been tightened.
- Inspect insulation for discoloration and signs of heat damage.
- It is important to monitor the condition of isolation dampers.
- Check cooling fan functionality and clean the fans.
Dry-type transformer tap changer
The tap changer is located at the center of the HV coil. It is a busbar used to adjust the transformer’s output voltage. You can change the transformer ratio by adjusting the location of the tap changer. Normal operation does not always result in nominal voltages for medium voltage.
There are two types of tap changers: de-energized tap change (DETC) or tap changer with a load (LTC).
HS code and requirements for dry-type transformer clearance
It is vital to import documents correctly to avoid any problems with local authorities. The manufacturer must provide the correct HS code at the time of purchase order. Prior to placing an order, it is important to investigate local rules regarding transport safety and insurance coverage.
The Harmonized System (HS), or HS codes, are used in the entire export process. The Harmonized System (HS) is an international classification system that allows countries to classify goods traded for customs purposes. The Harmonized System (HS) is a six-digit system used at the international level.
This post was written by Justin Tidd, Director at Becker SMC! For nearly a half a century, Becker Mining has been at the forefront of industry safety. Becker/SMC is the industry’s leader in increasingly more sophisticated electrical control systems. Most of the major innovations, design features and specialized electrical components have been developed by Becker/SMC.