Push Button Switches
Operator-actuated switches used for start, stop, reset, jog, acknowledge, enable, and other control-panel commands.
CONN / SWT — ELECTRICAL SWITCHING REFERENCE
Industrial Switches.
Industrial switches open, close, select, transfer, or signal electrical circuits in machinery, automation, control panels, process systems, material handling equipment, instrumentation, and industrial facilities. A switch may be operated manually by a push button, lever, key, rotary selector, or toggle; mechanically by machine motion; or automatically by pressure, position, level, temperature, or another process condition. Selection depends on contact arrangement, switching function, voltage, current, load type, actuator, operating force, travel, electrical life, mechanical life, mounting, terminals, environmental sealing, enclosure protection, safety requirements, and compatibility with the control circuit.
OPERATING PRINCIPLE
A switch changes the electrical state of a circuit.
Industrial switches use movable electrical contacts, solid-state circuitry, or another switching mechanism to create or interrupt an electrical path.
In a simple control circuit, activating a switch may send an input to a PLC, energize a relay, command a contactor, start a machine function, stop equipment, select an operating mode, or indicate that a mechanical condition has occurred.
The physical actuator and electrical contacts are separate parts of the specification. Two switches that look similar externally can perform very different electrical functions.
BASIC SWITCH IDENTIFICATION
NO
Normally open contact that closes when actuated.
NC
Normally closed contact that opens when actuated.
Pole
Number of electrically separate circuits controlled by the switch.
Throw
Number of output positions available to each switched pole.
Momentary
Returns to its normal state when the actuator is released.
Maintained
Remains in its selected state until deliberately changed.
SECTION / 01
Common Industrial Switch Types
Switches can be classified by actuator, electrical function, sensing method, mounting arrangement, and operating environment.
Rotary Switches
Turn through defined positions to select circuits, modes, ranges, speeds, functions, or operating states.
Selector Switches
Panel-mounted switches commonly used to select manual/automatic, forward/reverse, local/remote, or other machine modes.
Limit Switches
Mechanically actuated by machine movement to detect position, travel limits, doors, guards, cams, or moving mechanisms.
Toggle Switches
Lever-operated switches used for direct operator control in panels, machinery, test equipment, and electrical assemblies.
Rocker Switches
Pivoting operator switches often used for on/off control and equipment interface applications.
Pressure Switches
Change electrical contact state when fluid or gas pressure reaches a defined operating point.
Foot Switches
Allow operators to control a machine or process while keeping both hands available for another task.
Key Switches
Require a removable or controlled key to authorize machine operation, mode selection, or restricted functions.
ELECTRICAL / CONTACT LOGIC
Contact arrangement defines what the switch actually does.
The actuator tells the operator how a switch is used. The contact arrangement determines how it behaves electrically inside the control circuit.
COMMON CONTACT CONFIGURATIONS
SPST
Single-pole, single-throw arrangement controlling
one circuit between two states.
SPDT
Single-pole, double-throw arrangement transferring
one common contact between two outputs.
DPST
Two separate circuits are switched together
between open and closed states.
DPDT
Two circuits each transfer between
two possible contact paths.
NO
Contact remains electrically open
in its normal unactuated condition.
NC
Contact remains electrically closed
in its normal unactuated condition.
Changeover
Common terminal transfers between
normally closed and normally open paths.
SECTION / 02
Electrical Load, Actuation & Environment
Switch life and reliability depend on both the electrical load being switched and the physical conditions under which the device operates.
Electrical Load
Resistive, inductive, motor, lamp, capacitive, and low-level signal loads can impose very different demands on contacts.
Actuation
Operating force, travel, actuator style, reset behavior, and mechanical alignment determine how the switch interfaces with the machine.
Service Life
Mechanical and electrical life ratings indicate expected switching cycles under specified operating conditions.
Environmental Protection
Dust, oil, coolant, moisture, washdown, chemicals, temperature, vibration, and outdoor exposure affect switch selection.
SECTION / 03
Industrial Switch Specifications
A replacement switch must preserve electrical function, mechanical fit, actuator behavior, circuit ratings, terminal arrangement, and environmental protection.
Specification
What to Verify
Why It Matters
Contact Form
NO, NC, SPST, SPDT, DPST,
DPDT, multi-pole, or other arrangement.
Determines the actual circuit logic performed by the switch.
Voltage
AC or DC circuit voltage and applicable contact rating.
Contacts must safely interrupt and carry the actual circuit voltage.
Current
Continuous and switching current for the actual load category.
Excess current can overheat or damage switch contacts.
Load Type
Resistive, inductive, motor,
lamp, capacitive, electronic,
or low-level signal load.
Contact ratings may change substantially with load type.
Actuator
Push button, roller, lever,
plunger, rotary knob, toggle,
key, foot pedal, or process input.
Determines how the switch physically interacts with the operator or machine.
Action
Momentary, maintained, snap action,
spring return, detented, or alternate action.
Determines what happens after the actuator is released.
Terminals
Screw, clamp, solder,
quick-connect, cable, plug,
connector, or PCB termination.
Determines wiring compatibility and installation method.
Mounting
Panel cutout, threaded body,
flange, snap-in, rail,
bracket, or machine mounting.
Similar-looking switches may use different mounting geometry.
Protection
Dust, water, oil, washdown,
chemical, vibration, temperature,
and enclosure requirements.
Determines suitability for the actual industrial environment.
SECTION / 04
Industrial Switch Selection
Start with the required circuit action, then match the electrical load, actuator, mounting, environment, life expectancy, and machine controls.
01
Define the Function
Determine whether the switch must start,
stop, select, transfer, detect position,
indicate pressure, authorize operation,
or perform another control function.
02
Define Contact Logic
Identify the required number of poles,
throws, normally open contacts,
normally closed contacts,
and changeover contacts.
03
Evaluate the Load
Record AC or DC voltage, current,
load type, startup current,
inductive characteristics,
switching frequency, and circuit protection.
04
Choose the Actuator
Select the operator or machine interface:
push button, rotary selector,
lever, roller, plunger, toggle,
key, pedal, pressure input,
or another actuator.
05
Match Installation
Verify mounting dimensions, panel cutout,
actuator position, terminal orientation,
wiring clearance, cable entry,
and mechanical travel.
06
Validate Environment & Life
Confirm enclosure protection, temperature,
vibration, contamination, washdown,
switching frequency, mechanical life,
electrical life, safety requirements,
and control-system integration.
Compatibility / Note 18
A physically identical switch may have completely different electrical behavior.
Industrial switches with the same panel diameter, actuator shape, or housing size can differ in contact arrangement, normally open and normally closed states, number of poles, voltage rating, current rating, load category, momentary or maintained action, terminal assignment, operating force, travel, environmental sealing, mechanical life, electrical life, and safety function. Verify the circuit diagram and complete switch specification before substitution. See the Industrial Power & Electrical Reference, Part Specifications, and Component Compatibility Guide.
SECTION / 05
Industrial Switch Resources
Additional industrial references for electric switches, push button switches, rotary switches, pressure switching, controls, and electrical interfaces.
Electric Switches
Industry resource covering electrical switch manufacturers, switch types, applications, contact arrangements, configurations, and related technical considerations.
Research Electric SwitchesPush Button Switches
Focused resource for push button controls used in industrial machinery, control panels, automation equipment, and operator interfaces.
Research Push Button SwitchesRotary Switches
Supporting resource for rotary electrical switches used to select circuits, operating modes, positions, ranges, and machine functions.
Research Rotary SwitchesSensors & Controls
OpenType reference covering sensing, machine feedback, process detection, switches, controls, and industrial automation.
Sensor ReferenceIndustrial Power & Electrical
Broader reference covering transformers, power supplies, connectors, switches, protection, controls, and electrical systems.
Electrical ReferenceElectrical Connectors
Compare industrial electrical interfaces, terminals, conductor arrangements, current, voltage, sealing, and physical compatibility.
Connector Reference
Reference note:
External resources are provided for additional research
and do not establish product compatibility,
interchangeability, certification, approval, or endorsement.
Verify contact arrangement, normal state, voltage,
current, load category, number of poles and throws,
actuator, momentary or maintained action, operating force,
travel, terminals, mounting dimensions, sealing,
environment, mechanical life, electrical life,
control logic, and safety requirements before specifying
or replacing an industrial switch.
RELATED / ELECTRICAL CONTROL
Continue the Electrical Control Reference
Continue into sensors and controls, load cells, process instrumentation, and electrical system components.