Product Details

Test Switch Product Description

The W3TS Test Switch, a miniature knife blade switch (5/8 inch centers including barrier) with #10-32 stud terminals, is available in three types: Basic Switch, Short-Circuiting Switch (Shorting Switch), Test Jack Switch

All test switches may be either front or back connected.

  • Front-connected test switches are mounted on the front of a panel and are both operated and wired from the front.
  • Back-connected test switches are mounted on the front of a panel with extended terminal studs projecting through to the rear of the panel. This allows them to be operated from the front and wired from the back. Additional barriers and spacers insulate the extended terminal studs.

The three types of test switches can be arranged in any combination of elements with 1 to 52 poles in a single block. The arrangements can also include single terminals, through bars and blank spaces. Diagrams of standard elements are available in the Element Configuration Document.

The operator can choose to open or close the W3TS Test Switch by placing a standard 5/16″ nut driver on the patented TestSwitch, LLC safety knob. Pull up to open, down to close. It keeps fingers away from current-carrying parts. (See Safety Knob Instructions.)

Our patented footed barriers separate the test switches and wrap beneath them to form a non-conductive mounting plate for the test switch block. No metal mounting plate and no potting. Mounting rods support the weight of the block. Stainless steel mounting ears at each end of the block attach it to any surface.

Each W3TS Test Switch can be operated independently or, for simultaneous operation, adjacent handles can be ganged together with an insulated yoking bar. Test switches can be electrically connected with a common bar.

Standard handle colors are red for potential and black for current. A variety of colored handles, marker tags and tamper-proof covers that accommodate wire seals are available.

The W3TS Test Switch
The W3TS Test Switch

Applications for Test Switch W3TS 600 Volt 30 Ampere Miniature Test Switch

Power Systems

Multi-circuit testing, calibrating, disconnecting, troubleshooting, and checkout of control systems, meters, relays, instruments, transformers, and transducers where space is at a premium.

Make, break or re-arrange connections of an energized electric circuit without disturbing permanent wiring.

Safe and easy access to wiring on panelboards and switchboards.

Other systems where the W3TS Test Switch is applied include:
  • Water Parks
  • Mining Operations
  • NASA Vacuum Chamber Tests
  • Space Exploration and Technology
  • Boating Industry
  • Testing Equipment for UL and the Utility Industry
  • Network Protection in the Power Grid
  • Transformer Testing
  • Military Advanced Weapons
  • Steel Mills
  • Product Safety Testing
  • Electric Fence Maintenance
  • Resistor Panes
  • Train and Rail Industries
  • Petrochemical Construction
  • OEM Machinery

Back-connected Test Switches

Side view: Ten-pole block of back-connected switches
Single-pole back-connected switch
Back view: Ten-pole block of back-connected switches
Three-pole block with cover

Back-Connected Test Switcheshave insulated studs that project from the rear of the switch. When the switch is mounted to the front of a panel, wiring can be connected to the rear-projecting studs at the back of the panel.

All three types of test switches — Basic switch, Short-circuiting (Shorting switch), and Test Jack switch — are available in the back-connected version. All back-connected switches come with tamperproof clear thermoplastic covers.

Advantages of TestSwitch, LLC Test Switches

Front-connected Test Switches
Back-connected Test Switches
  • Dependable-The W3TS Test Switch performs reliably after more than 30,000 operations.
  • Safer-The safety-knob handle and thermoplastic mounting plate provide maximum operator protection . (See Safety Knob Instructions.)
  • Space Saving-The W3TS Test Switch (with barrier) measures only 5/8 inch wide.
  • Versatile-Unit-pole construction permits unlimited arrangement of switch elements with 1 to 52 poles in a single block.
  • IEEE Qualified-The W3TS Test Switch meets the IEEE C37.90 — Standard for Relay and Relay Systems Associated with Electric Power Apparatus.
  • Recognized by UL-The W3TS Test Switch qualifies at 600 Volts, 30 Amps in the United States and Canada under UL Standard 414 (7th Edition) and Standard C 22.2 No. 115-M1989–Standards for Meter Socket Bases and Associated Assemblies, Meter Switches.
  • ANSI Compliant-The W3TS Test Switch complies with ANSI  C 33.31 — Standard for Knife Switches.
  • ISO Registered-The TestSwitch, LLC Test Switch manufacturing process is ISO 9001:2015 registered.
  • RoHS Compliant-The W3TS Test Switch is RoHS compliant as per EU Directive 2002/95/EC.
  • SVHC under REACH Compliant -The W3TS Test Switch complies with SVHC under REACH as per June 2012 Revision
  • Compatible-The W3TS Test Switch substitutes directly for States® Type MTS Test Switch.

Test Switch Features



  • Non-ferrous materials – highest quality copper (blade), phosphor-bronze (jaw, hinge, spring washer, shorting element, test jack,) and brass (terminal studs, rivets, assembly nuts and screws) are used for all current-carrying metal parts.
  • Nickel plating protects all current-carrying components including hardware. This corrosion-resistant nickel finish ensures good electrical contact and smooth operation of moving parts even after years of inactivity.
  • Stainless steel is used for mounting ears and mounting hardware.
  • Self-extinguishing flame-retardant thermoplastics rated at Underwriters Laboratories’ best rating (V-O) are used in all non-metal components.

Tamper-proof cover attaches to insulated studs that have holes for wire seals.

Test Switch Specifications

  • The Element Configurations Document ( in a printer-friendly format ) shows the diagrams for the test switches and for standard groupings of test switches used for quotations and ordering.
  • Rated for up to 600 Volts and 30 Amperes.
  • IEEE qualified under C37.90 – Standard for Relay and Relay Systems Associated with Electric Power Apparatus.
  • UL qualified in the United States and Canada under Standard 414 (7th Edition) and Standard C 22.2 No. 115-M1989; reference UL file E189531.
  • ANSI compliant under C 33.31 – Standard for Knife Test Switches.
  • SVHC under REACH Compliant as per June 2012 Revision
  • RoHS Compliant as per EU Directive 2002/95/EC.

A Marker Tag Specification Drawing is available for customer-supplied marker tags.The Test Switch Specification Drawing and a Mounting Dimensions Table are available in a printer-friendly format.


Dimension Code:

  • A = Width of Switch Block overall, including Mounting Ears
  • B = Distance between centers of Mounting Ear slots
  • C = Width of Switch Block with Barriers (including Barriers automatically provided at each end of Switch Block, but not including Mounting Ears)
  • D = Width of Cover
  • E = Width of recommended panel cutout for Back-Connected Test Switch Blocks
  • F = Length of Mounting Rod

Dimension Equations: ( In Inches )

  • C without Cover = ( Number of poles * 5/8 ) + 1/16 [see Note]
  • C with Cover or Back-Connected = ( Number of poles * 5/8 ) + 3/16 [see Note]
  • A = C + 7/8 [and Add 1/8 inch if DIN Rail mounted]
  • B = C + 7/16
  • D = C + (1+1/16)
  • E = C
  • F = C + 9/16

Note – To allow for extra mounting support, for 26-50 poles add 5/8 inch to C; for 51 or more poles, add 1 ¼ inches to C.

Add-on / Options

  • Opaque and Clear Covers
  • Phase Barriers
  • Colored Handles (standard are red and black)
  • Marker Tag Labeling
  • Marker Tags (pre-cut)
  • Stud Nuts (brass/nickel plate 10x34 threads) Common Bars
  • No Knob Handles

13555 West 107th Street

Lenexa KS 66215



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