Why Do You Need a Vacuum Pump System for Evacuating Transformers?

Transformers play a crucial role in electrical systems, stepping up or down voltage to ensure efficient power distribution. However, before these transformers are commissioned for use, it is essential to evacuate them to create a vacuum environment. This process involves the use of vacuum pump systems, which play a vital role in ensuring the optimal performance and longevity of transformers.

What is a Vacuum Pump System for Evacuating Transformers？

A vacuum pump is a device designed to remove gases from a sealed container to create a vacuum. Various methods are employed by vacuum pumps, including mechanical, physical, chemical, or a combination of these techniques. The primary purpose is to reduce the pressure inside the container, thereby evacuating gases and creating a vacuum. Vacuum pumps are utilized in a wide range of applications across industries, including manufacturing, research, and, as in the case we’ll explore, the electrical power sector.

A vacuum system refers to a condition where the gas within a confined space is at a pressure below atmospheric pressure. The term “vacuum” indicates a state of dilute gas, and the degree of vacuum is a measure of the gas dilution in this vacuum state. It is often categorized into “high vacuum” and “low vacuum.” A high vacuum implies a more effective vacuum with a lower gas concentration, while a low vacuum suggests a less effective vacuum with a higher gas concentration.

Role of Vacuum Pump System in Evacuating Transformers:

In the context of large power transformers, the vacuum pump system plays a crucial role in two main processes:

• Vacuum Drying of Transformers:

Large power transformers often contain insulating materials and oil that can absorb moisture. Moisture is detrimental to the transformer’s performance and can lead to issues such as reduced dielectric strength and accelerated aging.

The vacuum pump system is employed to evacuate the transformer, effectively removing moisture and other gases. This process is known as vacuum drying, and it helps ensure that the transformer is thoroughly dried before being put into service.

• Vacuum Pumping During Vacuum Oil Filling:

When filling the transformer with insulating oil, it is essential to maintain a vacuum to remove air and gases from the transformer tank. This ensures that the insulating oil fills the transformer without trapping air bubbles or contaminants.

The vacuum pump system is used to create and maintain the required vacuum during the oil-filling process, contributing to the overall efficiency and reliability of the transformer.

In summary, the vacuum pump system serves a critical role in maintaining optimal conditions within transformers, contributing to their efficient operation and longevity. The processes of vacuum drying and vacuum oil filling, facilitated by the vacuum pump system, are essential steps in preparing transformers for service in electrical power systems.

Precautions When Transformer Vacuuming

Vacuuming a transformer is a crucial process that requires careful attention and adherence to safety protocols. Here are some important precautions to consider when evacuating a transformer:

1. Wear appropriate personal protective equipment (PPE) such as safety glasses, gloves, and, if necessary, respiratory protection. Ensure that the PPE complies with safety standards.
2. Operators should be trained, and after passing the assessment, they should be familiar with construction drawings, technical data, and construction site conditions before they can work.
3. Ensure proper ventilation in the working area to prevent the accumulation of gases. This is particularly important during the evacuation process when gases and vapors may be released from the transformer.
4. When the transformer is evacuated, since the different components in the transformer have different requirements for the degree of vacuum, it should be strictly implemented according to the technical data of the manufacturer. Prevents accessories such as capsules, oil pillows, or heat sinks from being able to withstand full vacuum, resulting in rupture, air leakage, or severe deformation. For old equipment and accessories that cannot be fully vacuumed, such as an oil conservator, heat sink, or on-load switching oil chamber, the valve should be closed to take isolation measures.
5. Be aware of temperature variations during the vacuuming process. Some transformers may experience temperature changes, and this can affect the evacuation efficiency. Adjustments may be needed based on ambient conditions.
6. If you want to supplement different grades of transformer oil, you must do a mixed oil test first, and then you can use it after passing the test.
7. When the environment is relatively bad, such as rain, snow, and heavy fog, vacuum oil injection should not be carried out to prevent the transformer from being damp.

About YUNENG Transformer Evacuation System

YUNENG’s vacuum pump for transformer evacuation finds applications in various industries, including vacuum smelting, welding, drying, chemical and pharmaceutical processes, as well as in electric vacuum devices. It serves the purpose of creating a vacuum in different industrial settings.

Maintenance tasks involve extracting vacuum from electrical vacuum devices within transformer substations, power supply administration, power generation plants, and transformer manufacturing. The ZJ series operates at a vacuum degree of 133Pa, with a limit vacuum degree reaching as low as 1Pa.

Parameter	Unit	ZJ-70	ZJ-150	ZJ-300	ZJ-600	ZJ-1200
Power Supply		50Hz    380V    3-Phase 4-Wire  (or as requested)
Power Supply	KW	4	6.5	7	11	18.5
Limit Vacuity	Pa	≤3
Pumping Speed	L/S	70	150	300	600	1200
Pumping Level		2
Connection Diameter	mm	50			80

YUNENG’s Transformer Evacuation Vacuum Pump for Transformer Maintenance has unique features:

1. Swift initiation, a rapid pumping rate, consistent performance, and user-friendly operation define this system.
2. Utilizing a roots pump as the primary pump and a spinning vacuum pump as a pre-stage pump, the unit ensures efficient evacuation.
3. Precision is maintained with the use of a vacuum meter, employed to measure and control the vacuum within the pumped container.
4. The incorporation of French Schneider Electric as the control element adds a layer of reliability to the system.
5. Operating in a fully automatic and unattended mode, the system features indicator lamps that provide real-time information on its operational status. Additionally, it boasts a humanized design, characterized by low noise levels, minimal energy consumption, and cost-effective circulation.

Explore a range of transformer evacuation systems from YUNENG, offering you diverse options to suit your specific needs.