Circuit Breaker Accidents and Troubleshooting

When the circuit breaker refuses to close, it should first check the operating power supply voltage (generally 220V) and closing power supply voltage (typically 240V). If it is not normal, it should be dealt with before closing. If it is still not enough, check the closing circuit insurance. Whether or not the circuit is broken, check whether the arm of the operating mechanism is turned over, whether the normally closed contact is disconnected prematurely, and open the isolation barrier, manually operate the flexibility of the test mechanism, if not, notify the maintenance personnel to deal with it. . If you jump again after meeting, check that the protection, operating circuit, closing circuit, and operating mechanism are slipping.

Circuit breakers refused to trip should be handled as follows:

1. The switch that the operating organization refuses to trip shall not be put into operation.

2. When the switch power supply circuit monitoring signal is found, it is necessary to check whether the fuse is blown at the site. Secondly, check whether the signal relay malfunctions and whether the operating circuit monitoring relay is disconnected.

3. When the cause of switch refusal jump cannot be found at once, and if the switch refusal jumps will cause the accident to expand, the following measures shall be taken: (1) If it is a 35KV and 6KV outlet switch, it should be manually jumped off the switch and then notified for The electricity department is handled by the maintenance workshop. (2) If it is 110KV switch and generator outlet switch, it should ask for a midtone adjustment and apply for shutdown. (3) If it is a lead switch and a tie switch, you can switch the brake and change the operation mode. After taking the above measures, the factory leaders will be reported promptly.

If it is found that the oil switch is seriously short of oil or there is a discharge sound inside, it should be considered that the switch cannot safely disconnect the circuit. The following measures should be taken at this time:

1. Stop using the switch. Other switches can be used to cut the load on the 35KV and 6KV line switches when they are deactivated. If it is 110KV and the generator outlet switch, the load should be adjusted so that the current through the switch is close to 0, and then the switch is opened.

2, if the switch heat is not normal (110KV and 35KV switch should be in the inspection process, hand touch the temperature, 6KV switch is mainly to observe the color), should strengthen monitoring, if the temperature continues to rise, it should be handled according to the accident, Stop using this switch.

In the vacuum switch operation, one of the following conditions is found, and the breaking operation is strictly prohibited:

1. Breaking of the interrupter shell;

2. Discharge sparks appear in the arc extinguishing chamber;

3, operating mechanism stuck;

4, the glass enclosure vacuum interrupter indoor shield oxidation color.

Before the vacuum switch is ready to be put into operation, one of the following conditions is found, and closing operation is strictly prohibited;

1. Breaking of the interrupter shell;

2. Glass shell arc extinguishing indoor shield oxidation color;

3. When the operating mechanism is stuck and the vacuum switch is disconnected and the switch is found to have serious discharge, the upper switch must be disconnected immediately to avoid explosion.

If there is a jump in the switch during operation, the power supply should be turned off immediately to inform the maintenance personnel to make adjustments and it is forbidden to continue the operation.

When the isolating barrier is accidentally engaged (if the load is switched on), it is not allowed to reopen the closed isolation barrier under any circumstances (regardless of whether one-phase, two-phase and three-phase are closed). Only after the circuit is opened by a switch, the isolated barrier can be opened.

When the isolating knife is accidentally pulled, the initial operation should be continued. If the accidental pull has caused short-circuit arcs, fire, etc., the operator should try to disconnect the power immediately.

When the isolating knife contact part is overheated, it is necessary to try to reduce its load immediately. If the isolating cutter is connected with the bus bar, it should be stopped as much as possible. If the temperature of the isolating knife bar rises sharply, the connected switch should be used to cut it off.

It is forbidden to use isolation knife gates 411G, 412G to charge the main transformer, nor is it allowed to open the 411G, 412G with the no-load transformer.

After the 51DL and 52DL are automatically tripped, they shall be closed again according to the instructions of the on-duty dispatcher. If the closing is not successful, the cause shall be ascertained.

If the voltage transformer has the following damage phenomenon, the circuit breaker is used to cut off the fault. It is forbidden to pull off the faulty voltage transformer by using an isolating knife.

1. The fuse plate on the high voltage side of the transformer is continuously blown for two or three times.

2. There are blasting sounds or other abnormal sounds inside the transformer.

3, transformer oil, smoke, serious oil spills, plastic flow and the internal issue of coke odor.

4. The coil or lead wire has spark discharge or casing crack on the shell. 5. The transformer isolation barrier has arc discharge or obvious grounding.

Where the switchgear is on fire, two firefighting principles must be observed:

1. Disconnect all power and possible incoming calls (including secondary circuit power) before firefighting

2. Use only sand or carbon dioxide fire extinguisher and dry powder fire extinguisher to extinguish fire. Do not use water and foam fire extinguisher to extinguish fire.

The time for one-point grounding of the 6KV and 35KV systems must not exceed 2 hours. When the ground signal occurs, the following steps can be used to find the grounding point:

1. Jump 10 DL, (31DL or 32DL) to divide the bus into two sections to find the faulty section.

2. If the 6KV system is grounded, it is necessary to switch between the 07DL and 13DL to distinguish whether it is inside or outside the plant.

3, if it is within the factory, you should first check the busbar, capacitors, arresters and other grounding signs, and then request the stoppage of the unit and the transformer, etc. to check, until the ground to find.

4. If it is an out-of-line fault, you can open each feeder in short order to find the grounding point and exit the circuit. The opening sequence should generally be: first, later important, more branches first, less after the branch; first long and short; first unilateral, after the two sides of the line.

5. For particularly important users, grounding operations can be allowed within 1 to 2 hours, but they should be notified as soon as possible to prepare for power outages, and cut off the faulty lines within 2 hours.