Electrical Switches and Controls

Switch action first, then the electrical rating

This aisle sorts by how the switch acts. Push buttons give momentary or latching action, rocker switches sit flat in a panel and show their state at a glance, and toggle switches give a firm on-off feel; ON-OFF-ON versions add a center-off position. Bluetooth and radio-frequency controls replace wiring runs. Whatever the style, compare the contact rating in amps and volts with the load, and check whether it is rated for AC or DC, because DC is harder on contacts and usually carries a lower rating.

Mounting style, enclosure rating and listings

Mounting style decides the cutout and the wiring. Panel-mount switches fit a round or rectangular hole and are held by a nut or clips, surface-mount sits on a wall, through-hole parts solder into a circuit board, and plug-in types push into a socket. For damp or dusty places look for an ingress rating such as IP65, which is dust-tight and protected against water jets; IP00 means no protection. UL Listed or CSA marks matter when the switch is part of mains wiring. Some listings here are computer parts, so read the full title before you buy.

Questions about Electrical Switches and Controls

What does ON-OFF-ON mean on a toggle switch?

It describes three positions: on in one direction, off in the middle, and on again in the other direction. The two on positions usually connect different circuits, which is how one switch can select between two loads or reverse a motor. Check the wiring diagram on the data sheet.

Can I use a mains-rated switch on a DC circuit?

Not automatically. DC does not pass through zero, so contacts break a steadier arc and DC ratings are lower than AC ratings for the same switch. Use a switch that states a voltage and current rating for DC at or above your load.

How do I find the hole size for a panel-mount switch?

The data sheet gives the mounting hole or cutout dimensions, often in millimeters. Also check the panel thickness against the threaded length, because the body must pass through the panel and still leave enough thread for the nut to tighten.