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The role of the disconnector
PUBLISHER:Shanghai Moye Electric Co.,Ltd””RELEASE TIME:2017/7/13
Isolated switch is the most used in high-voltage switch electrical appliances, as the name suggests, is isolated from the circuit in its own working principle and structure is relatively simple, but due to the use of large, high reliability requirements, the substation , The design of the power plant, the establishment and safe operation of the impact are larger. The main features of the knife is no arc suppression capability, only in the absence of load current in the case of sub-combined circuit.
When the disconnector is in the sub-position, there is an insulation distance and a clear opening mark between the contacts. In the joint position, the current under normal circuit conditions and the abnormal conditions (such as short circuit) Of the current switching device.
Relative to the knife switch, isolation switch or there is a certain degree of superiority, there is a single page, so now gradually replaced by automatic air switch lock. Domestic use of the complexity of the occasion, the complete replacement of serious difficulties, so the current use is still quite wide, the current main disconnector is mainly reflected in two aspects:
1, isolated power supply, to ensure safety
The main purpose of the disconnector is to ensure the safety of the service when the unit is overhauled. Between the parts to be repaired and the other live parts, a sufficiently large visible air insulation interval is formed with an isolating switch. Disconnector fracture in any state can not occur spark discharge, so its fracture pressure is generally higher than the ground insulation voltage 10% to 15%. If necessary, should be attached to the disconnector on the ground switch for grounding when used for maintenance.
2, switching operation
Use an isolating switch to switch an electrical device or line from one bus to another.
The sequence of operations between the circuit breaker and the disconnector
(In the equipotential state, the isolating switch can also be operated separately), the order of operation between the circuit breaker and the disconnector must be strictly observed, and must not be carried with a load puller (ie, the disconnector ), Otherwise it will cause misuse, resulting in an arc and cause serious consequences.
Disconnector is mainly used to high-voltage power distribution devices need to power off part of the live part of the reliable isolation to ensure the safety of maintenance work. All the contacts of the disconnector are exposed to the air and have a clear disconnect point. The isolator does not have an arc extinguishing device and can not be used to cut off the load current or short circuit current. Otherwise, under high pressure, the breaking point will produce a strong arc , And it is difficult to self-extinguish, and may even cause arcing (relatively or interphase short circuit), burning equipment, endangering personal safety, which is the so-called "with load pull disconnector" serious accident. The disconnector can also be used to switch some of the circuits to change the way the system is operating. For example, in a double bus circuit, you can use a disconnector to switch the running circuit from one bus to another. At the same time, can also be used to operate some small current circuit.
When the disconnector is in the sub-position, there is an insulation distance and a clear opening mark between the contacts. In the joint position, the current under normal circuit conditions and the abnormal conditions (such as short circuit) Of the current switching device.
Relative to the knife switch, isolation switch or there is a certain degree of superiority, there is a single page, so now gradually replaced by automatic air switch lock. Domestic use of the complexity of the occasion, the complete replacement of serious difficulties, so the current use is still quite wide, the current main disconnector is mainly reflected in two aspects:
1, isolated power supply, to ensure safety
The main purpose of the disconnector is to ensure the safety of the service when the unit is overhauled. Between the parts to be repaired and the other live parts, a sufficiently large visible air insulation interval is formed with an isolating switch. Disconnector fracture in any state can not occur spark discharge, so its fracture pressure is generally higher than the ground insulation voltage 10% to 15%. If necessary, should be attached to the disconnector on the ground switch for grounding when used for maintenance.
2, switching operation
Use an isolating switch to switch an electrical device or line from one bus to another.
The sequence of operations between the circuit breaker and the disconnector
(In the equipotential state, the isolating switch can also be operated separately), the order of operation between the circuit breaker and the disconnector must be strictly observed, and must not be carried with a load puller (ie, the disconnector ), Otherwise it will cause misuse, resulting in an arc and cause serious consequences.
Disconnector is mainly used to high-voltage power distribution devices need to power off part of the live part of the reliable isolation to ensure the safety of maintenance work. All the contacts of the disconnector are exposed to the air and have a clear disconnect point. The isolator does not have an arc extinguishing device and can not be used to cut off the load current or short circuit current. Otherwise, under high pressure, the breaking point will produce a strong arc , And it is difficult to self-extinguish, and may even cause arcing (relatively or interphase short circuit), burning equipment, endangering personal safety, which is the so-called "with load pull disconnector" serious accident. The disconnector can also be used to switch some of the circuits to change the way the system is operating. For example, in a double bus circuit, you can use a disconnector to switch the running circuit from one bus to another. At the same time, can also be used to operate some small current circuit.