High-voltage circuit breaker hydraulic mechanism troubleshooting

The failure of the hydraulic circuit of the high-voltage circuit breaker mainly occurs in the summer months when the temperature is high in July-August. The hydraulic mechanism used in Shengli Oilfield substation high-voltage circuit breaker is CY5, CY3, CYA. Take CY5 as an example. The common faults are: frequent start of oil pump, abnormally high pressure, abnormally low pressure, and long time for the oil pump to stop. Pressure, refuse to move or reject.

1. The oil pump starts frequently

Under normal conditions, the oil pump 24h is started 1 or 2 times. The frequent start of the oil pump is caused by a drop in the piston rod caused by internal leakage of the hydraulic system. External leaks are obvious and easy to handle. Internal leaks need to be carefully checked.

(1) The oil level of the tank drops below the safety valve, observe the leakage of each oil drain hole and safety valve, and check whether the oil drain hole in the oil tank is leaking.

(2) If the assembly valve has no leakage point, check whether there is any leakage inside the oil pump. Remove the low-pressure pipeline, observe whether there is oil leakage from the joint, or if the high-pressure joint check valve is badly sealed, remove it.

(3) If the closing position does not leak, leakage occurs only at the opening position, which may be a poor seal of the secondary cone valve or a damage of the seal ring of the cylinder piston. Replace the seal ring or grind, replace the poppet valve.

2. The pressure is abnormally high

(1) First check that the pressure gauge is intact.

(2) Since the piston rod of the pressure accumulator stays at the position of the oil pump, the pressure is gradually increased and the high pressure oil enters the nitrogen chamber.

(3) After the oil and gas mixture is mixed, replace the seal ring after dismantling. Be careful when changing the rubber pad.

(4) If the piston rod is far away from the micro switch, consider whether the micro switch has malfunctioned, or whether the contactor is normal, and the bad person should handle it.

3. Abnormal pressure is low

(1) If it is caused by nitrogen pressure relief, check whether the pre-pressure is acceptable. Check the connection point of the inflation valve, upper end cap and pressure storage cylinder with soapy water to determine the leak point and treat it symptomatically.

(2) If the piston rod of the accumulator cylinder is in the normal position and the pressure continues to drop, the cause is the leakage at the weld of the accumulator cylinder.

4 pump pressure for a long time or not pressure

The oil pump is switched off from zero pressure to the micro switch (1W). The pump is qualified within 3 minutes, and the pressure is longer than 3 minutes. Check whether the oil pump check valve or the high pressure outlet check valve seal and the oil pump plunger seal are not tight; whether there is air inside the oil pump; whether the clearance of the oil pump plunger is too large; whether the bolt in the oil pump is loose. The phenomenon that the oil pump does not press up is that the oil pump has been running and the pressure stops at a certain value and does not rise. It may be that the high pressure oil discharge valve is not closed, the low pressure oil inlet pipe is blocked, the gas exists in the oil pump, the oil pump check valve is not tightly sealed, and the seal Or the pad is damaged. Pressure contactor due to aging caused by poor contact with the main contact, pressure circuit can not be turned on. CJ-40 can be used instead of CZO-40. The replacement pressure contactor has excellent performance, improves dustproof and rainproof performance, and has no troubles in operation so far. Micro-switches are sealed and should be replaced after damage. When replacing, check that the contacts are good, the housing insulation meets the standards, and there is no jamming at the top.

5. Refused or rejected

The main reason is the disconnection of the closing and closing coils or the poor contact of the coil joints; the closing and closing of the solenoid valve stems of the closing and closing valves; deformation and bending; the valve stems of the closing and closing valves are too short; the operation circuit or the auxiliary switch is not good, causing a poor closing circuit . Use a multimeter to check the contact condition of the closing coil resistance, circuit or auxiliary switch. The closing valve stem should be adjusted to be too short. The closing position of the closing ball of the first-order valve should be positive.

6. The hydraulic oil is not clean

Faults caused by unclean hydraulic oil account for about 60%. The measures taken are: use qualified hydraulic oil to clean the high and low pressure pipelines; remove all the parts removed with hydraulic oil to remove impurities; Dough wipe mechanism box; use fine silk cloth to remove impurities such as iron filings in hydraulic oil.