Depending on the voltage class, the current repair of power transformers can be carried out from once a year to once every four years. Usually this event is implemented by a team of three people, and all the necessary work is carried out with the removal of tension.
Maintenance of power transformers consists of a clear sequence of defined operations. First you need to check the status of the transformer. This is achieved through the inspection of all available places, parts, as well as monitoring of protective grounding. If during the test it was found that one of the radiators was heated more than the others, then it is necessary to identify the cause and eliminate it. Disconnection of equipment is preceded by a check of the heating of contacts in places of connections not accessible for inspection. Contact prone to overheating, you need to sort out and clean.
If there is dirt in the tank, lid, radiator or expander, it must be removed. The condition of the drain valve and the lower radiator caps is checked. If necessary, replacement of the packing is made, the bolts of the covers and radiators are tightened.
The process of inspecting and removing dirt from the space under the expander involves cleaning the copper mesh. It is also necessary to wipe the oil indicator, drain the dirty oil and water sludge using a special valve that provides communication with the expander.
The need to replace silica gel is confirmed by chemical analyzes. To reduce the acidity of transformer oil, it is advisable to use the process of automatic regeneration in a thermosiphon filter. In order to limit the moisture content entering the oil along with the air, special air purifiers should be installed on thermosiphon filters.
During operation, the state of silica gel is monitored by observing its color. The signal for more attention is the color in blue of individual crystals. If the phenomenon is widespread, it is necessary to replace the dryer.
Current repair of power transformer transformer oil processing of the ATC type of the GlobeCore trademark allows topping up high-voltage oil-filled hermetic bushings with degassed oil during installation, repair, and operation of power transformers.
A huge advantage of this equipment is the ability to select the mode of operation. Depending on the current needs of an ATC installation, they can do one of the following:
- preparation (degassing) of oil;
- oil storage;
- oil transportation;
- topping up the oil.
The equipment is quite mobile, which makes it very convenient when servicing several groups of power transformers.