Wires and connectors for limit switches
2-wire 10mm2 yellow-green connector 284-107
- EAN: 4045454084585
- Manufacturer: wago
2-wire protective spring connector 0.08-6mm2 black ST 16-PE 3036165
- EAN: 4017918821098
- Manufacturer: phoenix contact
Holder for grounding wire max fi 10 with connector 12501105
- EAN: 5907676710415
- Manufacturer: elko-bis
Cables and connectors for limit switches
Limit switches, classified as auxiliary switches, play an important role in industrial automation. Their operation depends on the position of the machine (e.g. a robot arm) or a specific object in an industrial process (e.g. an object moving on a conveyor belt). An important role of the limit switches is not only to control devices, but also to protect guards and fences against unauthorized access during machine operation.
Cables and connectors for limit switches - types
Regardless of the function of the limit switches in a given control system, devices operate by means of the flow of current and therefore require a physical power supply from a medium, usually copper wire. The power cord is connected to the limit switch through a choke or a connector with the shape best suited for a given application. Cables and connectors for limit switches are selected depending on the environmental requirements and the location of the devices.
Cables for limit switches
The role of wires in every electrical installation, regardless of whether we deal with its high-current or control part, is to transmit energy at a voltage level appropriate for a given implementation. In the case of a three-phase electrical installation, the transmission medium is usually five-core copper wires (three cores for each of the three phases, neutral and protective conductors). A single-phase 230 V cable is equipped with three cores - one phase, one neutral and one protection.
The cables most often used in industrial automation systems are flexible control cables in PVC insulation (similarly to high-current installations). PUR insulation is also used, but regardless of the material used, it is also important for control cables to have single or double shielding, which guarantees compliance with electromagnetic compatibility requirements.
In industrial conditions, control cables are very often exposed to harmful substances, therefore their coatings are highly resistant to various types of chemical compounds and oils. In the food and pharmaceutical industries, hygiene and even sterility of technological processes is very important, therefore the cables used to power devices such as limit switches must be resistant to strong disinfecting and cleaning agents.
Another hazard in industrial conditions is fire. Both high-current and control insulated cables are manufactured as halogen-free and self-extinguishing, not supporting the flame. The next group of cables used in industrial automation are intrinsically safe control cables, used in industrial plants in potentially explosive areas (e.g. in the chemical or petrochemical industries).
Connectors for limit switches
Connectors in industrial automation intended for devices such as limit switches often operating in harmful conditions, require special materials and proper protection of electrical connections. The connectors are usually made of non-flammable materials, resistant to high temperatures, aggressive agents and moisture, and their design ensures safe connection of the cable with the device.
Manufacturers of limit switches usually offer a wide range of connectors that can be adapted to both environmental conditions and the specific location of the device. Sometimes the connectors are mounted in such a way that they require an approach from the bottom (usually rubber glands or straight connectors are sufficient), and sometimes the cable is led from the side of the device. Then, a good solution turns out to be an angular connector adapted to a cable with a specific cross-section, usually equipped with a screw terminal on the side of the conductor and a gland on the side of the device.