Breaker fault handling

1. What is the principle of circuit breaker fault handling?

The principle of handling circuit breaker failure is mechanical first, then electrical. Because the failure of the mechanical part is not eliminated, make With the electric operation, it is easy to expand the scope of the accident.

2. What to do if the circuit breaker trolley is not pushed in place? (Mechanical failure)

Check: Check whether the locking lever is deformed, whether the locking hole is shifted, whether the right side locking plate is in place, and the aviation plug is closed behind Whether the lock lever is deformed.
Treatment: The deformation of the locking lever can be handled on the spot or removed depending on the situation. If the locking hole is shifted, you need to pull out the trolley to the outside of the compartment and enter Adjust the locking hole into the compartment. If the right locking plate is not in place, use the operating handle to operate it in place. The locking lever changes after the aviation plug
The shape needs to be pulled out of the compartment, enter the compartment to adjust, or remove for processing.

3. How to deal with the circuit breaker refusing to close? (Mechanical failure)

Check: Use the operating handle to manually close the brake. There are two faults: A. The closing mandrel is not in contact with the bracket. B. The closing ejector rod has pushed the carriage roller to the closing position, but the roller is not held after the operating handle is released, and it drops with the ejector rod.
Treatment: Case A is the bracket position deviation or the bracket fixing pin falls off. Check carefully under the condition of good light. The mechanism, if the position is offset, adjust and reset according to the offset direction; if the bracket fixing pin falls off, reassemble the roller The shaft is fixed with qualified pins. Case B is that the closing and locking meniscus has been buckled too little or not so that the closing cannot be maintained. Tune The return spring on the right side of the meniscus makes the opening position of the meniscus appropriate. Reject points. Note: The above two points need to be carried out when all the energy of the circuit breaker is released.

4. How to deal with circuit breaker rejection? (Mechanical failure)

Check: There is no response when pressing the emergency opening button, and no response when stepping on the emergency opening plate. Reason 1: Deformation or detachment of the shutter fall. Reason two: The shutter plate and the connecting rod fell off. Reason three: The angle of the opening connecting plate of the mechanism is too small. Reason 4: The opening spring has fallen off.
Treatment: If the reason is one, remove the shutter plate, reshape it and restore it to its original shape and fix it in its original position again. If it is the second reason Then reconnect the shutter plate and the connecting rod. If it is the third reason, adjust the opening and connecting plate of the mechanism to make the angle slightly less than 180 degrees. if For the fourth reason, screw the opening spring into the plate hole again.

5. What to do if the circuit breaker trolley cannot be pulled out? (Mechanical failure)

Check: Whether the right side locking plate has been unlocked. Whether the emergency opening connecting rod is stuck. If no abnormality is found in the above inspection, So basically the limit switch connecting rod has been shifted to the front of the circuit breaker.
Treatment: Unplug the aviation plug, open the cover of the circuit breaker, and let a smaller person drill in from the underside of the circuit breaker and remove it. The lower side baffle of the front end of the circuit breaker, pull out the trolley, and reinstall the baffle.

6. How to deal with the circuit breaker refusing to close? (Electromagnetic operating mechanism, electrical circuit failure)

Inspection: One person closes the circuit breaker on the control panel, and one person observes the circuit breaker locally. There are the following categories Phenomenon: A. The contractor has no action and no sound. B. The contactor has action, and the circuit breaker cannot be closed. C contactor has action, break The circuit breaker was opened quickly during closing.
Treatment: There are five possible types of A fault: (1) Poor contact or damage to the trip switch of the circuit breaker. (2) Circuit breaker navigation The empty plug makes poor contact. (3) The contactor coil is burnt out. (4) Poor contact of auxiliary switch contacts. (5) The circuit is disconnected. When processing, compare the secondary diagram and use a multimeter to check the potentials of the corresponding lines on the terminal block, the lead pole of the contactor coil, the closing coil, and the auxiliary switch node point by point. The resistance of each loop can also be measured when the control bus is disconnected. In case of the situation (1) Pull out the trolley to the outside of the compartment, deal with or replace the travel switch. In case of emergency, the node can be short-circuited directly on the terminal block. Encounter In condition (2) unplug the aviation plug, disassemble the plug, and check whether the wiring is loose or falling off and whether the contacts are discharged or oxidized. Replace or overhaul according to the process. In case (3) just replace the contactor coil. In case of the situation (4) adjust the auxiliary switch Connecting rod or crescent plate, when adjusting, take into account the opening auxiliary node, otherwise replace the auxiliary switch. In case (5), the available line Connect it with the reserved length, otherwise use the reserved line to replace it. There are three types of B faults: (1) Contact of the contactor bad. (2) Burning or aging of the closing coil. (3) Poor contact or fusing of the closing fuse. In the case of (1) remove The movable contact of the contactor is polished, the static contact is polished at the same time, and the gap between the dynamic and static contacts is adjusted within the range of 3.5-5mm. Encounter In case (2) replaces the closing coil. In case (3) remove the closing fuse, measure its resistance, and replace it if there is no resistance value. Otherwise, reinstall it until the fault is eliminated. There are two situations for category C faults: (1) Bad conversion of auxiliary switch contacts. (2) Together The meniscus has been buckled too little or not in the gate lock. In case of the situation (1) adjust the auxiliary switch connecting rod or the crescent plate. Take into account the opening auxiliary node, otherwise replace the auxiliary switch. In case of the situation (2) refer to the case of Type B of Machinery Category 2 for handling.

7. How to deal with circuit breaker rejection? (Electromagnetic operating mechanism, electrical circuit failure)

Inspection: One person opens the circuit breaker on the control panel, and one person observes the circuit breaker locally. There are the following categories
Phenomenon: A. The opening coil has no action and no sound. B. The opening coil is activated, but the brake cannot be opened.
Treatment: There are four possibilities for Type A faults: (1) Burning of the opening coil. (2) The contacts of the opening auxiliary switch are poorly converted. (3) The aviation plug of the circuit breaker is in poor contact. (4) The circuit is disconnected. When processing, check the endpoint by point with a multimeter according to the secondary diagram The potential on the corresponding line, the opening coil, and the auxiliary switch node on the sub-bank. It is also possible to measure each under the condition that the control bus is disconnected
Loop resistance. In case (1) replace the opening coil. In case of the situation (2) adjust the auxiliary switch connecting rod or the crescent plate, When adjusting, take into account the closing auxiliary node, otherwise replace the auxiliary switch. In case of situation (3) unplug the aviation plug and disconnect the plug Check whether the wiring is loose or falling off and whether the contacts are discharged or oxidized. Replace or overhaul according to the process. In case of the situation (4) When using the reserved length of the line to connect it, otherwise use the reserved line to replace it. There are three possibilities for Type B failure: (1) Institution The angle of the opening connecting plate is too small. (2) Magnetization or aging of the opening coil. (3) Too much insertion of the meniscus in the closing lockout. In case of the situation (1) When the adjustment mechanism opens the connecting plate to make its angle slightly less than 180 degrees. In case (2) replace the opening coil. In case of the situation (3) Adjust the return spring on the right side of the meniscus to make the opening position of the meniscus appropriate, but be careful not to adjust too much, so as not to cause data