Fusible and Non-Fusible Disconnect Switches

What Is a Disconnect Switch

A disconnect switch is a manually operated device that completely isolates electrical equipment from its power source, letting you de-energize a circuit safely for maintenance, inspection, repair, or emergency shutdown. It creates a visible, verifiable break in the circuit. Unlike electronic switching, the physical separation of contacts confirms that no current can reach downstream equipment. The National Electrical Code requires disconnect switches for motor-driven equipment, and they must be installed within sight of the equipment they isolate.

Wistex supplies disconnect switches built to meet OSHA lock-out/tag-out requirements while providing safe, reliable isolation for industrial equipment. Choose from fusible, non-fusible, and motor disconnect options up to 2000 A, all available in NEMA 4X and NEMA 12 enclosures for harsh or dusty environments. With rapid shipping and expert guidance, Wistex ensures you get the right switch for the job. Need overcurrent protection? Pair your switch with one of our circuit breakers.

  • OT400E03 | ABB Load-Switch
    ABB

    OT400E03

    Load-Switch

    $1,357.46
    $1,569.63
  • OT400E03CF | ABB 3P Xfer Sw 400A Nf Fast Trans Iec
    ABB

    OT400E03CF

    3P Xfer Sw 400A Nf Fast Trans Iec

    $4,161.95
    $10,297.12
  • OT400E12CL | ABB 3P Manual Xfer Sw 400A Closed Trans
    ABB

    OT400E12CL

    3P Manual Xfer Sw 400A Closed Trans

    $4,504.36
    $5,208.38
  • OT400E33 | ABB 6P Sw 400A Nf Iec 1000Vdc
    ABB

    OT400E33

    6P Sw 400A Nf Iec 1000Vdc

    $1,848.94
    $4,574.47
  • OT400E33CP | ABB 6P Manual Change Over Sw 400A
    ABB

    OT400E33CP

    6P Manual Change Over Sw 400A

    $4,116.30
    $5,274.80
  • OT400ES03 | ABB 3P Sw 400A Nf Ul98 Lh
    ABB

    OT400ES03

    3P Sw 400A Nf Ul98 Lh

    $1,446.09
    $1,708.92
  • OT400ES04 | ABB 4P Sw 400A Nf Ul98 Lh
    ABB

    OT400ES04

    4P Sw 400A Nf Ul98 Lh

    $1,928.13
    $2,229.48
  • OT400U02 | ABB 2P Sw 400A Nf 600V Ul98
    ABB

    OT400U02

    2P Sw 400A Nf 600V Ul98

    $1,216.74
    $1,806.25
  • OT400U03C | ABB 3P Xfer Sw 400A Nf D-D
    ABB

    OT400U03C

    3P Xfer Sw 400A Nf D-D

    $3,089.39
    $4,586.21
  • OT400U04 | ABB 4P Sw 400A Nf Ul98 Lh
    ABB

    OT400U04

    4P Sw 400A Nf Ul98 Lh

    $1,711.04
    $2,540.04
  • OT400U04C | ABB 4P Xfer Sw 400A Nf D-D
    ABB

    OT400U04C

    4P Xfer Sw 400A Nf D-D

    $3,374.65
    $4,231.73
  • OT400U04D | ABB 8P Sw 400A Nf Ul98 1500Vdc No Load
    ABB

    OT400U04D

    8P Sw 400A Nf Ul98 1500Vdc No Load

    $2,176.40
    $3,125.87
  • OT400U12 | ABB 3P Sw 400A Nf Ul98 600V
    ABB

    OT400U12

    3P Sw 400A Nf Ul98 600V

    $1,349.85
    $1,830.33
  • OT400U12-121 | ABB 3P Sw 400A Nf W/Dummy Pole
    ABB

    OT400U12-121

    3P Sw 400A Nf W/Dummy Pole

    $1,560.90
    $1,844.75
  • OT400U12-91 | ABB 3P Sw 400A Nf W/Dummy Pole
    ABB

    OT400U12-91

    3P Sw 400A Nf W/Dummy Pole

    $1,284.89
    $3,861.82
  • OT400U21 | ABB 3P Sw 400A Nf Ul98 600V
    ABB

    OT400U21

    3P Sw 400A Nf Ul98 600V

    $1,349.85
    $1,897.85
  • OT400U22 | ABB 4P 400A Nf Sw
    ABB

    OT400U22

    4P 400A Nf Sw

    $1,711.09
    $1,978.52
  • OT400U30 | ABB 3P Sw 400A Nf Ul98 Rh
    ABB

    OT400U30

    3P Sw 400A Nf Ul98 Rh

    $1,349.81
    $2,003.81
  • OT400U30C | ABB 3P Xfer Sw 400A Nf D-D Rh Ul98
    ABB

    OT400U30C

    3P Xfer Sw 400A Nf D-D Rh Ul98

    $3,089.39
    $4,586.21
  • OT400US03 | ABB 3P Sw 400A Nf 600V Ul98 Side Oper
    ABB

    OT400US03

    3P Sw 400A Nf 600V Ul98 Side Oper

    $2,428.69
    $3,294.52
  • OT400US04 | ABB 4P Sw 400A Nf 600V Ul98 Side Oper
    ABB

    OT400US04

    4P Sw 400A Nf 600V Ul98 Side Oper

    $1,882.46
    $2,553.18
  • OT40F3-TX/B50 | ABB Switch-Disconnector Incl.50 Pcs
    ABB

    OT40F3-TX/B50

    Switch-Disconnector Incl.50 Pcs

    $2,643.93
    $6,541.37
  • OT40F3/B50 | ABB 3P 40A Ul508 Nf, Qty1=Pack50
    ABB

    OT40F3/B50

    3P 40A Ul508 Nf, Qty1=Pack50

    $3,612.20
    $5,362.33
  • OT40F3C | ABB 3P 40A Ul508 Manual Xfer Sw
    ABB

    OT40F3C

    3P 40A Ul508 Manual Xfer Sw

    $273.76
    $406.40
  • OT40F3U/B50 | ABB 3P 40A Nf W/Metal Collar, Bulk 50
    ABB

    OT40F3U/B50

    3P 40A Nf W/Metal Collar, Bulk 50

    $4,467.85
    $11,053.93
  • OT40F4N2 | ABB Dis Sw, 4-P, 40A/600V, Nf Rtside
    ABB

    OT40F4N2

    Dis Sw, 4-P, 40A/600V, Nf Rtside

    $129.15
    $151.10
  • OT40F6 | ABB 6P 40A Ul508 Nf Sw
    ABB

    OT40F6

    6P 40A Ul508 Nf Sw

    $201.53
    $299.17
  • OT40FD9N2 | ABB Switch-Disconnector
    ABB

    OT40FD9N2

    Switch-Disconnector

    $285.18
    $329.75

Fusible vs Non-Fusible Disconnect Switches

Fusible disconnect switches combine circuit isolation with overcurrent protection in a single device. Fuses are built into the switch mechanism, so the switch both isolates the circuit for maintenance and clears short circuits and overloads automatically. Non-fusible disconnect switches provide isolation only and rely on upstream devices, such as circuit breakers or motor starters, for overcurrent protection. A fusible switch is typically specified where short-circuit protection is needed at the point of service, such as at a service entrance or in high fault-current applications. Non-fusible switches are the more economical choice where overcurrent protection is already handled upstream, and are commonly used for motor leads. Wistex fusible switches accept Class J, R, and H fuses.

Disconnect Switches We Offer

Our selection includes trusted brands and enclosure styles to suit virtually any industrial application.

Fusible Safety Switches

Fusible Safety Switches

Fusible disconnects provide short-circuit protection and meet NEC service entrance requirements. Ideal for high SCCR applications, these NF-rated switches accept a variety of fuse classes, including J, R, and H.

Non-Fusible Disconnects

Compact and economical, non-fusible disconnect switches offer a reliable means to manually isolate equipment for maintenance. These are commonly used for motor loads when protection is handled upstream.

Non-Fusible Disconnects
Enclosed Motor Disconnects

Enclosed Motor Disconnects

These all-in-one motor disconnects combine a switch and enclosure, making them ideal for local servicing points on rooftop units, pump panels, or machinery.

Lock-Out/Tag-Out Compliance

Disconnect switches support lock-out/tag-out procedures through padlockable handles that can be secured in the OFF position, preventing accidental re-energisation while maintenance is underway. Clear ON and OFF position indication allows anyone approaching the equipment to confirm its state without opening the enclosure.

Applications for Disconnect Switches

Wistex disconnects are field-proven across a wide range of industrial and commercial systems.

  • HVAC units
  • Machine tools
  • Pump panels
  • Rooftop equipment

Complete your motor control system with contactors and soft starters.

Why Choose Wistex for Safety Disconnects

Wistex is trusted for code-compliant solutions that meet real-world demands. We stock a wide range of fusible and non-fusible disconnect switches, with amperages from 30 A to 2000 A, and enclosure options built for your environment. Our experts can help you build out complete solutions with fuse kits, mounting hardware, and made-in-USA selections, all ready to ship fast.

Disconnect Switch FAQs

Need help choosing or sizing a disconnect switch? Start with these commonly asked questions.

A fusible disconnect switch is typically required when short-circuit protection is needed at the point of service, such as service entrances or fault-current applications. Many local codes also specify fusing for added safety.

To size a switch, multiply your motor's Full Load Amps (FLA) by 115%, consider voltage and phase, and select the correct fuse class. Browse our 30A disconnect switch options or filter by amperage to find your match.

A disconnect switch provides a safe means to isolate power, but unlike a circuit breaker, it does not offer overcurrent protection. Disconnects are ideal for lock-out/tag-out compliance and scheduled maintenance.