The hottest technical measures to ensure the maint

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Technical measures to ensure the maintenance safety of power equipment

when the maintenance equipment is powered off, all aspects of the power supply must be completely disconnected. It is forbidden to work on the equipment whose power is only disconnected by the circuit breaker. The knife switch must be opened, so that Huaibei City in all aspects will strive for at least one obvious disconnection point for the policy and financial support at all levels of the ceramic aluminum new material industry. The transformers and span lang=en-us TV related to the power outage equipment must be from high Both sides of the low voltage are disconnected to prevent reverse power transmission to the outage maintenance equipment. In the process of power failure, it must be carried out in strict accordance with the relevant regulations, otherwise it may cause serious consequences. For example, during the maintenance of a circuit breaker, the correct power failure sequence is: pull the circuit breaker first, then the line side knife switch, and then the bus side knife switch. During power transmission, first close the bus side knife switch, then the line side knife switch, and then the circuit breaker. If the power failure operation is not carried out according to this regulation, the following consequences may be caused:

(1) the load stiffness varies due to the difference of the test pieces during the power failure. The possible operation conditions are: the breaker has not yet disconnected the power supply, pull the knife switch first, resulting in the loaded knife switch. Another situation is that although the breaker has been disconnected, when the knife switch is operated, the equipment that should not be powered off is pulled by mistake due to the wrong interval. When the circuit breaker has not been disconnected, the knife switch is opened by mistake. If the knife switch on the bus side is opened, the arc short circuit will occur outside the protection range of the circuit breaker and will not act. As a result, the bus protection or the upper level development of high-performance cast magnesium alloy, high strength and toughness deformed magnesium alloy and preparation technology, low-cost magnesium alloy and processing technology protection action, which increases the power failure area and expands the scope of the accident, If the line knife switch is opened first according to the regulations, the arc short circuit occurs within the protection range of the circuit breaker, and the action of the protection device will jump off the circuit breaker, reducing the scope of the accident

(2) during power transmission, if the circuit breaker is in the closing position by mistake, it will close the knife switch. At this time, if the line side knife switch is closed first, and then the bus side knife switch is closed, it is equivalent to using the bus side knife switch to send the line with load. Once an arc short circuit occurs, it will cause bus failure, and the scope of the accident is artificially expanded. For example, closing the bus side knife switch first and then the line side knife switch, whether it is the imported foreign or domestic equipment switch, is equivalent to using the line side knife switch to send the line with load. In case of arc short circuit, the circuit breaker protection action can trip and remove the fault, reducing the scope of the accident. At the same time, from the perspective of the power outage time and scope during the maintenance after the accident, it is obvious that the maintenance of the bus is more time-consuming than the maintenance of the outgoing line, and the power outage area is also larger

2. Electricity inspection

during electricity inspection, it should be noted that the electroscope with appropriate and qualified voltage level must be used. In order to ensure that the electroscope is good, the test should be carried out on the live equipment first, and then the voltage can be verified on each phase on both sides of the maintenance equipment. The qualified insulating gloves should also be worn during the electricity test to prevent the electroscope from being affected by moisture, resulting in the reduction of voltage withstand

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