Application of Safety Key Interlocking System in Transformer Measuring Insulation

The security key interlock system is a kind of plug-in key mechanical interlock used in electrical equipment. It is a safe operating system that must be installed in order to prevent human error. Equipment safety. The safety key interlock system is simple, reliable, direct and effective, and is particularly suitable for interlocking between multiple switch cabinets or cabinet doors. Makes the operator easy to identify and eliminate misuse. In the power plant, manufacturing and other fields have a wide range of applications.

According to the requirements of the power operation specification, the transformer must be disconnected from the low-voltage 380V switch, then the high-voltage 6KV switch, then the 6KV switch grounded, and finally the transformer door can be opened to repair the transformer. According to this operating sequence, a safety key interlock system is installed on the 380V switch circuit breaker, the 6KV switchgear grounding knife and the transformer cabinet door, respectively. When operating, disconnect the 380V circuit breaker to pull out a key. At this time, the 380V circuit breaker is locked in the open state. Hold this key to unlock the grounding knife in the 6KV switchgear cabinet. (Note: 6KV circuit breaker can be borrowed here. The self-interlock between the device and the ground blade), the grounding blade is grounded, another key is pulled out, and the grounding blade is locked in the grounded state. At this time it has been ensured that both the low voltage and high voltage switches are de-energized and have been discharged to ground. Finally, take out the key to open the front and rear door transformers. Reverse operation can send power to the high and low voltage switches.

Safety key interlock system operation sequence:

Power off the 380V switch and take out the key 2A. The cabinet is locked in the power-off state. Turn the 6KV switch off. Use the 2A key to unlock the 6KV side grounding knife. Connect the grounding knife to the ground and pull out the 2B key. The ground knife is locked on the ground. In the state, use the 2B key to open the dry-type high-voltage side door, pull out a 2C key, and use the 2C key to open the dry-type low-voltage side door. After the experience of electricity, the personnel can carry on the overhaul of the transformer.

The above is merely an illustration of the application of the security key interlock system in the electrical switching operation, and it is not limited to these in practical applications. The statistics of a large number of electrical accidents show that the personal electric shock and death and electrical equipment accidents are often directly related to the technical level of electrical workers. According to the operation sequence of the safety key interlock system design, it can effectively avoid the occurrence of misoperation accidents.