The Knife Switch: Unleashing Power and Control

2023-05-25119 have been browsing

The Knife Switch: Unleashing Power and Control







In the world of electrical engineering, where power and control are paramount, the humble knife switch holds a special place. A knife switch is a simple yet significant device that has played a crucial role in the history and development of electrical systems. Its ability to complete or break an electrical circuit with a flick of a lever has revolutionized the way we harness and utilize electricity. From its early days to modern applications, the knife switch continues to serve as a symbol of power and control.

The knife switch, with its visible and easily operated lever, became an essential safety device. It allowed engineers and operators to quickly isolate circuits during maintenance or emergencies, preventing electrical hazards and minimizing the risk of electrocution.

The knife switch’s durability, reliability, and simplicity have ensured its survival and relevance in certain applications ,and it can still be found in a variety of settings. It is commonly used in educational environments to teach students about electrical circuits and the fundamentals of electricity.The tactile experience of flipping a knife switch can instill a sense of fascination and understanding, bridging the gap between theoretical knowledge and practical application.

Their primary purpose is to provide a visible and reliable means of isolating electrical circuits or equipment for maintenance and safety purposes.

Detail about Knife Switch


The main function of an Knife switch is to provide a visible means of isolation. It disconnects the electrical circuit or equipment from its power source, ensuring that no power flows to the circuit or equipment while work is being performed.

2. Manual Operation:

Knife switches are typically manually operated devices, meaning they require physical action by an operator to turn them on or off. This manual control allows for a direct and reliable disconnection of the power supply.

3. Disconnection of Power:

When the isolating switch is in the “off” position, it interrupts the flow of electrical current, effectively cutting off the power supply to the connected circuit or equipment. This disconnection prevents accidental energization and protects personnel working on the system.

4. Visible Position:

Isolating switches often have a visible position indicator, such as a handle or a switch blade, which clearly shows whether the switch is in the “on” or “off” position. This visibility allows workers to easily determine the status of the switch, enhancing safety and preventing accidental re-energization.

5. Multiple Poles:

Isolating switches can have multiple poles, which means they can disconnect multiple power sources or circuits simultaneously. This feature is especially useful in complex electrical systems where multiple circuits need to be isolated for maintenance or repair.

6. Ratings:

Isolating switches are available in various voltage and current ratings to suit different applications. The ratings of an isolating switch should match or exceed the electrical parameters of the circuit or equipment it is intended to disconnect.

7. Lockout/Tagout:

Knife switches are often used as part of a lockout/tagout (LOTO) procedure, which is a safety protocol to ensure that equipment or machinery is properly shut down and isolated before maintenance or servicing. Lockout devices or tags can be applied to the isolating switch to indicate that it should not be operated.

8. Knife switch Technical Specifications

Type Rated Voltage(kv) Rated current(A) 4S Heat steady current(A) Impulse withstand voltage(kv) Power-frequency withstand voltage(kv)
To earth Across the disconnccting distance To earth  Across the disconnccting distance
Antifouling Type FGW9-12/400 12 400 12.5 75 85 42 48
 FGW9-12/630 12 630 20 75 85 42 48
 FGW9-12/900 12 900 25 75 85 42 48
 FGW9-12/1250 12 1250 40 75 85 42 48
Plateau Type FGW9-15/400 15 400 12.5 110 125 47 54
 FGW9-15/630 15 630 20 110 125 47 54
 FGW9-15/900 15 900 25 110 125 47 54
 FGW9-15/1250 15 1250 40 110 125 47 54

More information can find in Zhejiang Zhongyi Electric Power.