Case Study
Nowadays, industrial switch plays a vitally important role in various industries like energy, environmental protection, transportation, smart city surveillance, etc. And the demand for industrial switches is also increasing.
Electrical Disconnect Switches
This type of disconnect switch is common on electric motors, including aircraft tow tractors, industrial forklifts, and agricultural vehicles. Electrical disconnect switches are also used on various appliances, including air conditioners and heaters. This helps ensure the safety of contractors working on the appliance.
Electrical disconnect switches usually adhere to the International Electrotechnical Commission’s (IEC) international standards or the National Electrical Manufacturers Association’s (NEMA) U.S. standards. However, both regulating bodies work together to create and uphold quality standards for electrical product manufacturers.
Disconnect switches are an integral part of electrical circuits in industrial and manufacturing settings. However, they also appear in standard, everyday settings.
Regardless of the application, they play a critical role in the grand scheme of things.
What is a Disconnect Switch?
A disconnect switch is a type of safety device used in electrical circuitry. The purpose of a disconnect switch is to guarantee that a particular electrical circuit is de-energized in the case of an emergency stoppage, service, or maintenance.
The disconnect switch allows operators to power down the circuit entirely, creating a safe environment for the operator to complete any necessary repairs, maintenance, or inspections. It ensures a lack of energy feeding through the circuit, relieving concerns of electrical risks.
Disconnect switches must meet specific, strictly regulated specifications and standards to ensure the function and design are guaranteed.
The main functions of safety switches such as these include:
- Protection against overload
- Protection for property
- Protection for personnel
- Protection against short-circuiting
- Protection against circuit overloads
- Protection against heat-generated damage
Where are they used?
Switchboards
A switch-disconnector is often used at the start of a switchboard to isolate the entire switchboard or individual sections for maintenance work. This allows safe work on the switchboard, without the risk of electrocution.
Industrial systems
In industrial environments, where safety is paramount, switch-disconnectors are used to isolate parts of machinery or production lines for maintenance or repair work, ensuring the safety of operators.
Distribution systems
In electrical distribution systems, switch-disconnectors can be used to isolate sections of line or transformers for maintenance or repair work, without interrupting the power supply to the entire plant.
Main features
Breaker function
Ability to interrupt the current flow in the event of an overload or short circuit, protecting the circuit.
Disconnect function
Ability to physically isolate the circuit, allowing safe maintenance work.
Mechanical interlocking
In some cases, the switch-disconnector may be equipped with mechanical interlocking with other devices (e.g. a circuit breaker) to ensure that isolation only occurs after the circuit has been safely disconnected.
In summary, a switch-disconnector is a versatile device that combines the functions of disconnection and isolation, offering greater safety when working on electrical installations, both civil and industrial.
If the problem is isolated to a specific area of a facility, disconnect switches allow operators to shut down the isolated area by itself. While operators or technicians handle the repair, the rest of the facility can continue operating normally. In turn, this ensures productivity levels stay relatively consistent.
The National Electric Code (NEC) mandates the use of disconnect switches in all industrial and manufacturing facilities. According to the NEC’s regulations (article 430.102B), safety switches must be in sight from all manufacturing equipment or motors. “In sight” means they must be visible and no more than 50 feet from the equipment it controls.
