V Cabinet Circuit Breaker Operating Mechanism Operating Procedure

General requirements for high voltage circuit breakers

1. The circuit breaker shall operate within the specified technical parameters.
2. The circuit breaker must be equipped with a reliable operating power supply and a closing power supply.
3. The power transmission should first close the knife gate and then close the circuit breaker; for a power outage, disconnect the circuit breaker and check that it has been disconnected before pulling the blade.
4. The inspection of 110kV high-voltage equipment can be carried out by one person, but the distance from the charged body should not be less than 1.5 meters.
5. 6kV switch operation regulations:

• The switch is maintained every 2000 operations, overhauled every 10 years or 6,000 operations, and minor repairs are carried out 20 times when the switch falls off (or according to the switch instructions);
•  After the switch is overhauled, the handcart should be pushed to the test position to jump and close the gate once. Switches that refuse to trip electrically are prohibited from being put into operation;
•  Staff on duty are prohibited from grabbing the contact arm during operation;
•  When the cable chamber of the switchgear needs to be overhauled, the V Circuit Cabinet Breaker Operating Mechanism handcart must be trimmed before the handcart can exit. At this time, the outlet voltage display light installed on the switchgear cabinet does not light up, and it is confirmed that there is no voltage before the ground cutter can be connected (at this time, the electrical test can be carried out at the static contact in the lower part of the handcart room).

6. Inspection items for vacuum circuit breakers:

• Whether the insulating porcelain column has rupture damage, discharge marks and dirt.
• Check the insulation rod. It should be completely free of cracks, each connecting rod should not be bent, and the spring should be in an energy storage state when the circuit breaker is closed.
• Check whether the contact area of the joint is overheated and whether the lead slack is moderate.
• Check whether the points and closing positions are correct and in line with the actual operation conditions at the time.

7. Situations where the V Cabinet Breaker Circuit Operating Mechanism requires special inspection:

• After the circuit breaker is operated or tripped;
• When the weather is abnormal;
• When overloaded or overvoltage;
• When the circuit breaker is running abnormally;
• Newly put into operation circuit breakers.

8. 6kV equipment inspection items:

• Check that the analog screen indicator is consistent with the actual position;
• Check that the switchgear points, closing signs, and signal lights are consistent with the actual position;
• Check that the live display at the power transmission interval is correct;
• Check that there is no abnormal sound in the 6kV switch room;
• There is no abnormal sound in the grounding transformer or arc extinguishing coil, and no heating phenomenon at the joint;

Preparation before transmission of electricity

1. Withdraw the work ticket, close the process, make an account, remove the temporary measures, and resume the fixed safety measures.
2. Under the following circumstances, disconnect the cutters on both sides and measure the insulation:

• Newly invested equipment;
• Devices that have been out of service for more than one month;
• When there is obvious moisture or when insulation is suspected to be low.
• When the switch after maintenance is in a state where the blade is disconnected (or the handcart is in the test position), the whole group test is good.

The following checks should be carried out before the circuit breaker is transmitted:

•  The circuit breaker should check that the gas pressure is normal.
•  The porcelain vase, casing and body should be clean, undamaged and not leaking;
• The fit and split position indicators should be correct;
• The phase spacer should be complete and undamaged;
•  The housing has good grounding wire;
•  The operating mechanism should be clean, the mechanical lever pin should not fall off, the tie rod porcelain vase should be flexible, unbroken, and the arc extinguishing cover should be correct;
• The switch body has no tools left behind, and the work site should be clean;
• The fixed fence should be intact, and the door should be tightly closed and locked;
• Tripping the iron core, the closing contactor should be flexible without jamming;
• The closing insurance shall be in good condition, and the rated current of the insurance shall comply with the relevant regulations.

Operation and operation of the circuit breaker

1. Basic requirements for operating V Cabinet Breaker Circuit Operating Mechanism

• The circuit breaker has no defects affecting safe operation. The circuit breaker’s blocking capacity should meet the bus short circuit current requirements. If the circuit breaker’s blocking capacity is equal to or less than the bus short circuit current, there should be a metal partition or wall isolation between the circuit breaker and the operating (working) mechanism. Remote operations should be carried out when conditions are available.
• The circuit breaker position indicator should correspond to the indicator light signal and meter indicator.
• Before the circuit breaker closes, check that the relay protection is put in according to regulations. The arrangement of the load carried should be considered before dividing the gate.
• It is generally not permitted to use manual mechanical circuit breakers.
• V Cabinet Breaker Circuit Operating Mechanism When the gas pressure reaches latching pressure, it is prohibited to operate the circuit breaker.
• When the number of trips of the circuit breaker approaches the maintenance cycle, the automatic closing device must be lifted.
• The control switch should not return too fast during operation. Wait until the red or green light signal is emitted before letting go, so as not to refuse to switch when the dividing and closing coils are energized for a short period of time. The electromagnetic mechanism should not return too slowly to prevent the auxiliary switch from failing and burning the closing coil.
• After the circuit breaker is closed, it should be confirmed that all three phases have been connected and that the automatic device has been set according to the regulations.

2. Items that should be checked when operating circuit breakers

• Check the position of the circuit breaker according to the current, signal and on-site mechanical instructions;
• A circuit breaker with a meter (real-time monitoring) should check the current, load and voltage conditions one by one;
• Before operation, check whether the hydraulic circuit of the control circuit and the auxiliary circuit controlling the power supply are normal, check whether the power mechanism is normal, and if the energy storage mechanism has stored energy, then the switch has operating conditions;
• Circuit breakers that have been out of service for a long time should be tested 2 to 3 times through remote control before formal operation; only after there are no abnormalities can they be operated in the prescribed manner;
• When an abnormal situation is found, the operator and professionals shall be notified immediately and the relevant treatment shall be carried out.

3. The general order of power transmission operations

• Check that the switch is in minutes;
• Invest in AC and DC insurance (or secondary switch);
• Push the handcart into the operating position (or close the blade belonging to the switch according to the principle of first closing the power side and then closing the load side);
• The corresponding closing operation can then be carried out.

4. The general order of power failure operation

• Disconnect the switch, the green light is on, check the meter instructions;
• Check that the switch is in minutes;
• Pull the handcart out of the cabinet (or open the knife brake to which the switch belongs, according to the principle of disconnecting the load side first, then the power supply side);
• Disconnect the operating power supply.

5. V Cabinet Breaker Circuit Operating Mechanism allows manual (mechanical) tripping under the following circumstances:

• The switch rejects electric tripping;
• Serious personal or equipment accidents require emergency shedding;
• Do debugging work after a power outage.

6. The V Cabinet Breaker Circuit Operating Mechanism prohibits manual closing (mechanical closing) under load. When accident handling must be manually closed, the approval of the operation department leader or dispatcher is required.
7. When the circuit breaker is split, it is not completely separated due to mechanical reasons (in a half-gate state). The circuit breaker should be closed manually immediately and reported to the operation department.
8. Inspection and maintenance of circuit breakers
9. In addition to the pre-transmission inspection items, the following items must be checked during the inspection of circuit breakers during operation:

• The circuit breaker itself and the mechanical part have no fracture or deformation;
• There is no rupture or discharge of the casing;
• Whether there is overheating or discharge;
• The secondary circuit is not loose, and the position of the auxiliary contact should be correct;
• Check that the circuit breaker is not making any noise.
• Close the switchgear door.

2. After the circuit breaker has tripped in an accident, the following checks should be carried out:

• There are no signs of fever, burn, or deformation at each joint;
• The air switch should check the main contact for burnout, and the mechanical part of the V Cabinet Circuit Breaker Breaker Mechanism should be complete and good.
• When the switch is in standby state, the knife gate is in the closing position.
• The switch inspection items in the backup should be the same as the operating equipment.