Many Dwyer Instruments, Inc. switch products have standard snap-action switches. Snap-action switches have a mechanical movement that snaps the contacts together and apart to make or break an electrical circuit.
Silver contact snap switches are very versatile and offer high contact ratings commonly up to 10 or 15 amps when used with 120 volts AC. These switches are often used for control circuits with heavier load requirements such as pumps, motors, fans, and incandescent light bulbs.
Silver contact switches, however, do not work with applications that are low current and voltage, typically under around 300 milliamps. These switches are often used for logic circuits for controllers, computers, and similar applications that are looking at a discrete signal (versus having a high load).
With low current applications, the silver contact builds up a layer of oxidation that prevents the contact from completing the circuit. This can be especially bad in applications that have long periods of inactivity or environmental conditions that accelerate the oxidation. Gold contacts do not have this oxidation issue.
If you have an application where this is a concern, many Dwyer switch products offer a gold contact option. These include:
- Level Switches
- Flow Switches
- Pressure Switches
Please contact a Dwyer Technical Sales Representative with any questions at firstname.lastname@example.org.