Selector switches are available in a variety of styles including illuminated, non-illuminated, and non-illuminated key operated. Styles offered
range from maintained or spring return, incandescent or LED, and 3-50 amps. Work with a selector switch specialist to determine the best product
for your application.
This product overview focuses mainly on the construction and functionality of Non-Illuminated Selector Switches. The Non-Illuminated Selector Switch
is represented in both the Selector Switch Diagram as well as the Selector Switch Video Overview.
Selector Switch works on a general principle; they contain a simple selector switch on the front of the panel, and a broad range of potential
contact combinations (via the contact blocks), on the inside of the enclosure. The major difference between the selector switch and the pushbutton
is that, while a pushbutton has a plate that pushes down both contact plungers at the same time, a selector switch has a rotating cam with ridges
and flats, allowing to actuate the plungers independently.
Selector switches are available in 2, 3, or 4-position versions, and are often used when more than one control option is needed. In general, the
center position of the selector switch is the starting cam position. Left position presses the left plunger in the selector switch. Turning the
selector switch to the right presses down the right plunger.
Selector switches use cams in combination with contact blocks to provide a wide range of circuit openings and/or closings. In the following
diagram, "X" designates a closed circuit (energized or "on") for a particular selector switch position, and "O" to designate an open circuit
(not energized or "off").
In the figures below, a 3-position selector switch is used to open or close two circuits, "hand" and "auto", for a pump application. It works
in the following manner (reflects a left, center and right selector switch positions).
Indicating lights are part of selector switches. Setting a selector switch is how we tell machines how to operate. Indicating lights tell us what
the machine is do or failing to do. When a light is connected to a machine process, and the light is on, the machine shows that it's working.
Selector switches are used when more than one control option is needed (e.g. Hand-Off-Auto). These switches are preferred when a maintained
contact is needed.
Contact blocks are an integral part of selector switches. The contact block can have normally open (NO) and/or normally closed (NC)
configurations. Single circuits contain a contact block of either one normally open or one normally closed circuit. For applications that need
only one contact, a single circuit is an efficient, inexpensive way to get the job done. Dual circuits offer two contacts in a single
contact block. The combinations include:
1 normally open and 1 normally closed contact
2 normally open contacts
2 normally closed contacts
Combinations with special delayed opening or early closing contacts
Dual circuit contact blocks save space in enclosures and add twice the functionality to a switch because one switch operates two circuits.
You can add multiple contact blocks to increase functionality. For example, you can mount 4 dual circuit blocks to a 30mm pushbutton for a total
of 8 circuits.