A limit switch is an electromechanical device consisting of an actuator mechanically connected to one or more contacts. These are very important devices for safety, both in industrial applications and in those relating to commonly used systems.
In fact, when an object comes into contact with the actuator, the device acts on the contacts to activate (switch on) or deactivate (switch off) an electrical circuit.
Some of these switches are used in industry, while others are also present in our homes, for more common uses.
For example, in our appliances: you open the refrigerator and the interior light comes on, you close it and it turns off. This light switch is very similar to the limit switches found on industrial machines.
Limit switch for industry
Limit switches are indispensable in many applications and sectors and, depending on these, the most suitable type of switch must be chosen.
On industrial machines, more robust mechanical limit switches are required than in the example of the refrigerator seen above, but the operating principle remains the same.
These devices are indispensable for the safety of machines and especially for operators, since they are able to interrupt a mechanism, beyond a predefined position or action: if a travel mechanism malfunctions, for example, the limit switch deactivates the motion control avoiding serious damages (safety limit switch).
In other applications, the limit switch is used to limit a movement of the machine from one specific point to another (position sensors).
Limit switch in enclosure
The use of electromechanical limit switches in electrical cabinets deserves particular attention, because their intervention is aimed at disconnecting circuits, to protect operators. The inspection for control, maintenance, or expansion purposes requires some sections to be under-voltage, while others not.
The lighting and service sockets must be listed among the parts that are always kept “live”, while the power circuits are subjected to sectioning by means of a manual reset limit switch.
Positioned near the cabinet opening, the limit switches disconnect the power supply of the power sections when the door is opened, but they can, at the need of the maintenance technician, be manually forced into the on position.
There are currently five models of mechanical limit switches in the Fandis range:
- plain plunger (FC-001, FC-005)
- plain plunger with manual reset (FC-002)
- roller plunger (FC-003)
- with adjustable lever (FC-004).
Each of these versions can meet different switching needs related to different applications.
For specific applications on electrical cabinets, Fandis offers pre-assembled and wired kits, such as article FD03, with an automatic reset limit switch, a manual reset limit switch, and a safety light signal.
The limit switches are part of the Indacus range which includes complementary solutions to improve the equipment but above all the efficiency of the electrical cabinet.
If you want to know more about our products for electrical panels and all other Fandis products, visit our website fandis.com or leave a comment to this article. One of our technicians will answer you as soon as possible.