Switching of tap changers
1. Use of load-controlled tap changer
1) Electric operation
(1) Normally, both AC and DC power supplies of the tap changer are on, and the manual crank should be removed;
(2) When the tap changer button is pressed, the red signal light comes on. At this time, the button should be released, and the tap changer switches to the adjacent level and the light goes out;
(3) After switching, check that the transmitter indicates the correct position and do not leave it in the bridge position;
(4) If the power is lost during the switching process and the switch stays in the middle position, the power should be restored immediately so that it automatically returns to the adjacent level in the direction of increase;
(5) If the mechanism is stuck during the switching process, the signal light does not go out, and the transmitter does not rotate, the power should be disconnected immediately and adjusted manually.
2) Manual operation
(1) Disconnect the DC power supply;
(2) Insert the manual crank and lock the pin on the horizontal shaft;
(3) Adjust from 1-10 levels to counterclockwise, and from 10-1 levels to clockwise;
(4) After switching, check that the transmitter indicates the correct position.
2. Use of off-load tap changer
1) The tap changer should be switched after disconnecting the switches and knife switches on each side and taking safety measures;
2) After the test personnel have completed the tap changer switching, they should measure whether the contact resistance is good and keep records.
3. After new installation or overhaul, the gas protection of the on-load voltage regulator should be intact and put into operation. Before the transformer is loaded, the on-load voltage regulator should be operated for one cycle, checked for abnormalities, and the direction should be adjusted to the required tap position.
4. The tap adjustment operation of the on-load voltage regulator transformer should be carried out according to whether the bus voltage is qualified or the dispatching order. When the main transformer is overloaded, voltage adjustment operation is prohibited;
5. When the light gas sends a signal, voltage adjustment operation is prohibited.
6. The on-load voltage regulator switching switch should be inspected after one year of operation or 4,000 operations. After the newly put into operation of the voltage regulator 5,000 times, the switching part should be hoisted out for inspection, and the inspection period can be determined according to the actual situation in the future.
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