When selecting a switch to use in electrical design, most people believe they can use any switch, provided its current rating is quite the utmost load within the circuit. This, of course, isn’t true. Alternating current (ac) or direct current (dc) circuits are capable of carrying completely different currents; this can be why it’s, therefore, necessary for designers and engineers to know a way to decide the correct switch for his or her product. Safety switches are key elements to several items of apparatus and plant floor operations. These sensors defend instrumentation and other people from damage. Non-contact safety switches have a distinctive price when used properly.
Always observe the subsequent cautions to make ensure safety.
- Mounting
Before mounting, dismounting, wiring, or inspecting a switch, make sure to turn OFF the power supply to the switch, otherwise, an electric shock could also be received, or the switch could burn.
- Wiring
Do not perform wiring once power is being equipped to a switch. Also, don’t touch any of the charged terminals when power is being equipped. Otherwise, the electrical shock could also be received.
Fig.1 – Wiring
Follow the directions provided in Correct Use for all wiring and soldering work. Using a switch with improper wiring or soldering could result in abnormal heating once power is equipped, presumably leading to burning.
- Contact Load
Select appropriate switch ratings when confirming contact load. If the contact load is excessive for the contacts, the contacts could weld or shift, presumably resulting to short-circuit or burning once power is equipped.
Precautions for Correct Use:-
Using Switches
When switches are used, unforeseen accidents could occur. Before using a switch, perform all potential testing before.
Unless otherwise such that, ratings and performances. When performing testing within the actual application, forever use constant conditions as will be used in actual usage conditions for each load and the operating environment.
Selecting Correct Switch
Select associate applicable switch for the operating environment and load conditions. Use the selection guide to pick an appropriate switch for the rated current, operating load, actuator type, and operating environment.
It is not counseled to use a switch for an outsized current to modify a small current, in terms of contact dependableness. Select a switch that is appropriate for the current being switched. Consider using a sealed switch in environments subject to water droplets.
Fig.2 – Selecting Correct Switch
Operation and Storage Environment
1. Handling
Do not apply oil, grease, or alternative lubricants to the slippy components of a switch. The intrusion of oil, grease, or alternative lubricants into the inner part may cause operative failure or contact failure.
2. Storage Environment
When storing a switch, contemplate countermeasures (e.g., storing in a plastic bag) to forestall discoloration ensuring from sulphurization of terminals (silver-plated).
Make sure that the placement is free from harmful gas and doesn’t have high temperatures or humidity. It’s counseled that a switch is inspected before use if it is stored for three months or more after the production, depending on the location.
Conclusion
Making the correct choice: Are you making an ac or dc circuit? And is the load that you’re switching inductive or resistive? Answering these two key queries can assist you to select the correct switch for your design. It’s always best to choose one that’s been certified to a recognized standard. This will guarantee it performs—both electrically and mechanically—the approach it’s intended.