Anti-vandal Switches Basics
- September 30, 2022
What are anti-vandal switches?
Anti-vandal switches are electrical switches designed to be installed in a location (or device) and application where they may be subject to abuse and attempts to damage them, as in the case of pedestrian crossing switches. Anti-vandal switches located on devices that are outdoors must be able to withstand extreme temperatures, dust, rain, snow, and ice. Many anti-vandal switches are intended to be operated by the general public, and must withstand heavy use and even abuse, such as attempts to damage the switch with metal tools. These switches must also resist dirt and moisture.
Pushbutton anti-vandal switches are frequently constructed of stainless steel or other durable materials, and are mounted into panels or housing boxes made out of strong materials, such as polycarbonate plastic, aluminium, or stainless steel. In some cases, the housing may be 1⁄4 inch (6.4 mm) thick, to protect both the switch and the housing from attempts by vandals to damage the switch or housing using blunt force. The housing for vandal-proof switches is often secured using security screws (which cannot be unscrewed with regular screw drivers). The height of buttons in the panel is often minimized by using flush-mounting, to make it more difficult to pry them out, a design technique used in ATM banking machines that are located outside. Anti-vandal switches often need to be water and dust resistant due to their environments.
Anti-vandal switches are often low-voltage, low current, so-called “signal” types intended to trigger a change in state, perhaps from “off” to “on” and vice versa. The mechanical types often have gold-plated contacts that do not corrode, to allow reliable low-power switching. A few types are capable of switching 120 or 220 V AC power at several amperes, and are better suited to direct switching of the AC power to a device than the gold-plated contact switches. Heavy-duty switches often have silver or silver-plated contacts to handle higher currents. Many but not all anti-vandal switches are momentary types; that is to say they only open or close a circuit while being depressed and revert to their inactive state when the button is released.
What scenarios are anti-vandal switches used in?
- Alarm, safety, and security systems
- Elevator buttons and security switches
- Automatic food and drink vending machines
- Pedestrian crossing signal activation switches
- Rental equipment that may be subjected to heavy use
- Electronic door switches for garages and mechanical gates
- Public address systems in schools, community centers, and bars
- Intercom “push-to-talk” devices at the entrance to apartment buildings
- Public interactive kiosks that provide tourist information or government forms