GAR_CAT_009_2018_GB_Page Turner

| 162 | gardnerbender.com SWITCH TERMINOLOGY UL/CSA RATED SWITCHES Single Pole (SP): A switch device that opens, closes or changes connections in a single conductor of an electrical circuit Double Pole (DP): A switch device that opens, closes or changes connections in both conductors of the same circuit. Two Circuit (2 CIR): A switch device that opens, closes or changes connections in a single conductor of two independent circuits. Single Throw (ST): A switch device that opens, closes or completes a circuit at only one of the extreme positions of its actuator. Double Throw (DT): A switch device that opens, closes or completes a circuit at both extreme positions of its actuator. Actuator: A lever, push-button, slide, trigger or other means by which an external force is applied to operate a switch mechanism. Normally Open (NO): A momentary type switch in which one or more circuits are open when the switch actuator is at its normal or rest position. Normally Closed (NC): A momentary type switch in which one or more circuits are closed when the switch actuator is at its normal or rest position. Alternate Action (Double Action Push): Push to make, then push to break, a circuit. Power Ratings for Switches: The current handling capability of a switch measured in amperes, horsepower, lamp load or combinations of these with applicable voltages. A UL/CSA-marked rating in amperes indicates that the switch meets or exceeds test house performance requirements of 6000 make-and-break cycles at the rated current, preceded by 50 make-and-break cycles at 150% switch current rating. 125% is used when switch ratings exceed 10 amperes. A UL/CSA horsepower-only rated device meets minimum test requirements of 50 make-and-break cycles at the appropriate locked rotor current, followed by 6000 cycles at one-sixth the AC-locked rotor current and 10% of the DC-locked rotor current. AC ampere ratings are resistive or inductive, with the inductive rating tested at 75% to 80% power factor. AC horsepower ratings are inductive and tested at 40% to 50% power factor. “L” Rating denotes ability of an AC-only switch to handle the initial high in-rush characteristics of a tungsten filament lamp on AC voltage only. “T” Rating denotes ability of an AC/DC switch to handle the initial high in-rush characteristics of a tungsten filament lamp on either AC or DC voltage. All DC ratings are 100% resistive only (non-inductive). Many AC-only rated switches can be used in applications where less than 30 volts DC is required, provided current does not exceed full current rating of the switch. Ampere-rated switches will not automatically handle in-rush characteristics of five to six times switch rating. SPST A switch that makes or breaks the connection of a single conductor in a single branch circuit. This switch has two terminals that are either connected together or disconnected. ONE CIRCUIT - ON/OFF A switch that makes or breaks the connection of two conductors in a single branch circuit. This switch has four terminals and is the equivalent of two SPST switches controlled by a single mechanism. TWO CIRCUITS - ON/OFF A switch that makes or breaks the connection of a single conductor with either of two other single conductors. This switch has 3 terminals and is commonly referred to as a “Three-Way” switch. ONE CIRCUIT - ON/OFF/ON A switch that makes or breaks the connection of two conductors to two separate circuits. This switch has six terminals and is the equivalent to two SPDT switches controlled by a single mechanism. TWO CIRCUITS - ON/OFF/ON A switch that makes or breaks the connection of a single conductor with either of three other single conductors or either or both of two conductors. ONE CIRCUIT - OFF/ON(A)/ ON(B)/ON(A+B) DPST SPDT DPDT SPTT LOAD "A" LINE LOAD"B" MOM. (ON) "A" OFF MOM. (ON) "B" LINE "A" LOAD "A" LOAD"B" LINE "B" ON OFF ON"1" LOAD"A2" LOAD"B2" ON"2" Line "A" Load"A1" Load"B1" Line "B" LINE LOADS “A” & “B” ACTIVATE WITH 3RD ON LOAD “B” LOAD “A” ON-A, ON-B, ON-A&B OFF ON OFF LOAD LINE