Momentary Action: Press and hold pedal to turn on, release to turn off (like a car horn).  The user must continue to hold the pedal down to keep it on.  As soon as the user lifts his or her foot, the unit will turn off.

Maintained Action: Press pedal once to turn on, press again to turn off (like a light switch).  The foot switch will stay on and the user can remove his or her foot from the foot pedal until the user presses the pedal again to turn it off.

Anti-Trip Safety Feature (G-Series only): The user must press forward a safety latch inside the hood before pressing down on the pedal lever to turn it on.  These foot switches then have a momentary action; the user must keep the pedal pressed down in order to keep it on.

SPDT Contacts: Most SSC foot switches with one switch in them have SPDT (single-pole double-throw) contacts, which have terminals including common, normally open, and normally closed.  Also called “Form C” contacts.  Typically, foot switches with cables on them have SPDT switch contacts that are wired to the "normally open" (or N.O.) and common terminals, which means the foot switch is off (no current will flow) until the pedal is pressed.

SPST-NO Contacts: These contacts close when the foot switch is pressed.  This is the most common foot switch circuit, one in which the circuit is “off” until the foot switch is pressed, at which point it turns on.  Also called “Form A” contacts.

SPST-NC Contacts: The opposite of SPST-NO, this circuit is closed in the at-rest position, and will open or turn off only when the foot switch is pressed.  Also called “Form B” contacts.

DPDT (Double-Pole Double-Throw) Contacts: Equivalent to two SPDT contacts operated by one control.

Double Break Contacts (SPDT-DB): Double break contacts open and close at two separate places in the circuit.  Because they make contact at two points, instead of just one, DB contacts dissipate heat more readily, providing longer switch life, enabling the switch to have improved performance in DC circuits, and typically handle higher voltages.  A SPDT-DB switch must be used on circuits of the same polarity.  Also called “Form Z” contacts.

Number of Poles: The Number of Poles determines the number of circuits that will be switched.  For example, a single pole (SP) switch will make and break one circuit, while a double pole switch (DP) will make and break two circuits.

Common (C): The Common terminal provides a path to the N.C. or N.O. terminals for a SPDT switch.  This terminal must be used for the foot switch to work, as it will direct the current to either the N.C. or N.O. terminals.

Normally Closed (N.C.): The N.C. terminal is connected to the common terminal in the at-rest position of the foot switch, and will open (or turn “off” if wiring is connected) only when the foot switch is pressed.

Normally Open (N.O.): The N.O. terminal is not connected until the foot switch is pressed, at which point the contacts close and allow current to flow from the common terminal to the N.O. terminal and complete the circuit.

Number of Throws: The Number of Throws is the number of separate wire paths the switch can direct for each pole.  Most SSC switches have double throw (DT) contacts, meaning there is a common wire, one that can be wired normally open (N.O.), and one that can be wired normally closed (N.C.).  Most SSC foot switches are shipped with the wiring set to Normally Open, meaning the switch is open or “off” until it is pressed, at which point the circuit closes and current can flow.

Foot Switch Wiring: See foot switch selection guide for more discussion about foot switch wiring.

SPDT (Single-Pole Double-Throw):

DPDT (Double-Pole Double-Throw):

SPDT-DB (Single-Pole Double-Throw, Double Break):