Within the field of enclosures, the use of electromechanical limit switches plays a crucial role. These devices are designed for circuit isolation, ensuring operator safety during inspections, maintenance, or expansions of electrical cabinets.
NO or NC contacts?
The choice between a switch with a normally open (NO) or normally closed (NC) contact in limit switches for electrical panels depends on the specific application requirements.
The Normally Open (NO) contact identifies a situation where the circuit is initially open and closes when the switch is activated or when a specific action occurs. It is commonly used in situations where you want the circuit to be closed only in response to a specific event, such as turning on a light when opening the electrical cabinet door.
The Normally Closed (NC) contact opens when the switch is activated or when a specific action occurs, interrupting the current flow. It is often used when the circuit needs to be interrupted in response to a certain stimulus, especially in safety functions, such as emergency stop switches. NC contacts are also used for scheduled interruptions, where the circuit needs to be regularly or under certain circumstances.
As you will see, some devices combine both types of contacts, offering greater flexibility. Most Fandis limit switches have both NO and NC contacts, allowing for various configuration options.
In summary, the choice between NO and NC contacts depends on the specific purpose of the circuit and the needs of the application in which it will be used.
1NO + 1NC limit switches (FC-001)
This type of limit switch, characterized by a simple plunger head, proves fundamental in the realm of electrical cabinets, precisely isolating power circuits when the cabinet door opens, using the normally open (NO) contact. Meanwhile, it could turn on an internal light using the normally closed (NC) contact. In the Fandis range, you’ll find the limit switch with a simple plunger head FC-001.
1NO + 1NC limit switches with manual reset (FC-002)
This limit switch not only isolates power circuits when necessary but also features a plunger head with a manual reset option. The Fandis FC-002 device is useful, especially in situations where manual reset is essential. For example, during a system failure, a qualified operator may need to intervene inside the control panel. In this case, opening the door would disable all internal circuits with the NO contact, and the operator could not troubleshoot. In such a scenario, the reset button allows restoring power inside the panel for the repair. Moreover, in special situations, when needed, the switch can be manually forced into the ON position.
1NO + 1NC limit switches with roller (FC-003)
When a variety of switching needs requires a versatile solution, the roller limit switch FC-003 comes into play. Its plunger head with a roller offers an alternative activation option, adapting with agility to different situations. The use of the roller can be advantageous in environments where space is limited, allowing for a more compact installation and greater flexibility in activation.
1NO + 1NC limit switches with adjustable lever (FC-004)
The limit switch FC-004 with plungers featuring adjustable levers offers a flexible solution for applications with specific switching needs. Adjustable levers offer the flexibility to adapt the lever length to the specific needs of the application. This is useful in situations where a customized adjustment area is needed for the lever movement, ensuring perfect adaptability.
3NC limit switches (FC-005)
The limit switch with a simple plunger head with three normally closed contacts FC-005 is designed for three-phase circuits.
Thanks to these options, Fandis range of limit switches offers tailor-made solutions for every need in switchgear, from the most basic to the most specific. Additionally, they stand out for full compliance with the highest safety and reliability standards. Each model, equipped with an IP65 protection rating, boasts a terminal block protected through the use of a cable gland and a cover with a protection class II, meeting various application needs in the industrial context.
For more information on choosing a limit switch, refer to this article.
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