Refilling of power transformers.
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Can a power transformer be refueled while in operation due to an excessively low oil level?
Sure. If heavy gas is used, it is necessary to disconnect the connections, and safety must be taken into account.
Power Transformer Operating Procedures 5.3.2 When the transformer is in operation and oil is filtered, replenished, the submersible pump is replaced, or the adsorbent in the oil purifier is changed, its heavy gas relay should be rerouted; meanwhile, other protection devices should still be connected to trigger tripping. One more thing: safety is of utmost importance; when working with high-voltage electrical systems that are in operation, all tasks must be carried out strictly in accordance with the established operating procedures.
Filtering should be done first; it’s not good if the oil isn’t up to standard!
First, filter the transformer oil and conduct a pressure test; only if it passes can the operations be carried out in accordance with the specifications
To be honest, it’s best not to refuel while the equipment is running – safety comes first. Whether it’s a state-owned enterprise or a private one, any safety issues will be the individual’s fault. It’s recommended to carry out such tasks after the equipment has been stopped. After all, it involves high voltage, which is very dangerous.
By how much is it low? What’s the reason for the decrease? Find out first.
It is permissible within the limits specified by the regulations. First, it is necessary to ensure that the insulating oil is of qualified quality, prepare the work order properly, take appropriate safety measures, and carry out the work only with the permission of the on-duty operator
First, identify the cause; in most cases it is due to temperature changes caused by seasonal variations, or it may be resulting from a reduction in load. It is possible to add oil during operation – simply remove the heavy gas protection first. Before adding oil, it is necessary to test the insulation properties of the oil or conduct a chromatographic analysis. It is best to use an oil filter for this purpose.
When refilling oil in a transformer that is in operation, its heavy gas protection should be switched to signal mode. It is also necessary to check the gas relay and allow any gas to escape promptly. Only after no gas is detected for three consecutive hours (some regulations specify 12 hours) should the heavy gas protection be switched back to the trip position.
It’s possible, but with some newer types of transformers, there is an air bag in the oil reservoir that makes it difficult to fill them with oil.
It can be added. Our transformer was leaking a little oil, but it couldn’t be shut down, so repairs were carried out while it was still in operation. As the people upstairs said, use qualified oil and pay attention to the switching of the pressure plates. However, it is not recommended to do so. Since refueling is done from the oil reservoir, it can push the condensed water and impurities accumulated at the bottom of the reservoir into the main tank, creating safety hazards.
Yes, but it is necessary to clarify the reason first; the heavy gas signal from the transformer is part of the tripping circuit, and the signal must be processed before it can be used
Fueling is possible, but it is important to ensure that the fuel meets the required standards. Relevant measures must be taken in accordance with the transformer operation procedures and your organization’s on-site operating guidelines. There are clear regulations regarding safety, and it is sufficient to follow them.
The transformer gas trip switch must be disengaged; safety measures must be taken to ensure safety, and a small amount of oil can be added after the transformer oil has been tested and found to be satisfactory.
Theoretically, it’s possible; in practice, however, there are many safety risks. It’s advisable to stop and refuel. There is a prerequisite: it must be a relatively large transformer that allows refueling from below. First, the oil must be tested to ensure it meets the required standards. The heavy gas release switch should be removed to prevent bubbles from forming during refueling, which could cause the heavy gas protection system to activate. Then, the oil should be poured into the transformer’s refueling port using an oil filter, and at that time the vent port must be opened. Those that cannot be oiled from below should definitely not take the risk.
It can be added; provided that the quality of the oil is satisfactory, remove the heavy gas first. After adding the oil and running the system for 48 hours, restore the heavy gas.
In theory, it is possible to refuel; one must pay attention to safety and follow the operating procedures strictly