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Master Lock

Master Lock Red Electrical Box Circuit Breaker Lockout, Tagout Breaker Box Lock for Standard Single and Double Toggles, 493B, 24 Amps

  • Based on 1,699 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Aug 24 – Sep 18
Order within 14 hours and 52 minutes
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Size: 1 Count (Pack of 1)


Style: Breaker Lockout


Features

  • Lockout tagout circuit breaker lockout is best used on standard height and tie-bar toggles typically found on 120 and 240 volt breakers; Best used as part of a comprehensive OSHA compliant lockout tagout safety program
  • Innovative patented Grip Tight design effectively locks out circuit breakers with a simple thumb turn and then close clamping handle for a tight grip on the toggle
  • Durable construction with powder coated steel and reinforced polymer for operation in harsh environments
  • 5-1/8 in. (13 cm) long circuit breaker lockout with 1-3/16 in. (3 cm) height and 2-3/4 in. (7 cm) depth
  • Includes one lockout tagout circuit breaker lockout; Accepts all Master Lock and American Lock safety padlock shackles and lockout hasps (padlocks and hasps sold separately)

Description

Master Lock 493B Lockout Tagout Circuit Breaker Lockout, Standard Single and Double Toggles fits standard height and tie-bar toggles typically found on 120 and 240 volt breakers. The innovative patented Grip Tight™ design effectively locks out circuit breakers with a simple thumb turn and then close clamping handle for a tight grip on the toggle. Device accepts all American Lock® and Master Lock® safety padlocks and most lockout hasps for full lockout. Durable construction and red color with powder coated steel and reinforced polymer stands up in harsh environments. Compact circuit breaker lockout design is easy to carry and store.

Brand Name: Master Lock


Model: 493


UPC: 071649229725


Part Number: 493B


Manufacturer: Master Lock


Warranty Description: Available


Global Trade Identification Number: 00071649229725


Item Weight: 0.05 Kilograms


Unit Count: 1.0 Count


Included Components: Unit^Instruction Guide


Item Type Name: Lockout Tagout Device Circuit Breaker Lockout


Best Sellers Rank: #22,140 in Industrial & Scientific (See Top 100 in Industrial & Scientific) #12 in Lockout & Tagout Devices


ASIN: B004J173I8


Customer Reviews: 4.6 4.6 out of 5 stars (1,699) 4.6 out of 5 stars


Current Rating: 24 Amps


Circuit Breaker Type: Standard


Mounting Type: Tie-bar


Number of Poles: 1


Smart Home Compatibility: Not Smart Home Compatible


Voltage: 240 Volts


Item Dimensions D x W x H: 2.76"D x 5.12"W x 1.18"H


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Aug 24 – Sep 18

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • So Simple And Effective
Size: Standard Single and Double Toggles Style: Circuit Breaker Lockout
I bought this breaker lock-out as a reminder to not turn this breaker on, unless you really need it. I use this on the 240V, 50 AMP, Electric Vehicle / Recreational Vehicle outlet that I installed under our breaker panel. Most of the time, this should be turned OFF, but on rare occassion it needs to be turned on. This Lock-out makes it really easy to remember to keep it turned Off when not needed and prevents people from turning it on by accident. The quality of construction is excellent and although I didn't need to use the fitment accessories that came with it, I appreciate that they were included. Nothing is as frustrating as not being able to finish a project beause of a fitment issue. Master Lock had this in mind and they have you covered. Great little product. I would definately buy it again. ... show more
Reviewed in the United States on October 6, 2023 by Anthony in AZ
    • Good for the price
Size: Standard Single and Double Toggles Style: Circuit Breaker Lockout
Works perfectly well for my application. Should make me compliant with safety rules.
Reviewed in the United States on February 28, 2026 by JohnC
    • Simple Solution
Size: Standard Single and Double Toggles Style: Circuit Breaker Lockout
Simple circuit lock. Easy to use. It does inhibit me from closing box cover due to height when it's attached to breaker but that is no fault of the product. Very happy with purchase.
Reviewed in the United States on January 18, 2026 by jjsMomma03
    • Not for 4-pole breakers with pairing braces Not for 4-pole breakers with pairing braces
Size: Standard Single and Double Toggles Style: Circuit Breaker Lockout
Review Image by CarpCaster
Review Image by CarpCaster
Review Image by CarpCaster
Review Image by CarpCaster
Review Image by CarpCaster
I bought this lockout for a four pole quadplex breaker. I wanted to shut off the inner toggles of a 240 volt, 40 amp breaker (see pictures). Because the outer metal pairing brace (AKA "that metal thingy"), the lock wouldn't engage with the inner two 40 amp toggles. The description does mention working with tie-bars such as what I have with the 40 amp toggles but when the outer metal pairing brace also exists, this lockout won't work. I've included some pictures that illustrate the problem. Dare I say better pictures than the seller provided. Although this device won't work for me, it seems to be a decent product. I am able to lock out single pole toggles ok. The grip of the toggle is pretty strong. Tighten with the thumbscrew. Then when you swing down the arm, it increases the pressure and it would take some work to pull it off. It might not be suitable to lock out a breaker from a neighbor stealing power but in a safety situation it should be fine. I'm going to keep this lockout for other breakers. I dropped a star mainly because the description is ambiguous, not because the device is poor. ... show more
Reviewed in the United States on June 5, 2024 Reviewed in the United States on June 5, 2024 by CarpCaster
    • Amazing product
Size: Standard Single and Double Toggles Style: Circuit Breaker Lockout
This is simple to use and highly effective. For roughly $10, it gets the job done and then some. Locally I tried to find something like this and it was $50. It clamps onto the breaker switch (whether it is on or off) and then the swing arm further tightens it. IT then has a loop you can use a zip tie or a small padlock. It can be pried off (with significant effort) but what you are really trying to do is make it difficult to "accidentally" move the breaker from the position you want. ... show more
Reviewed in the United States on February 28, 2024 by Henry Wolford
    • Works to cover unused breaker
Size: Standard Single and Double Toggles Style: Circuit Breaker Lockout
Works on regular fuse panel
Reviewed in the United States on February 15, 2026 by ckonly
    • Excelente
Size: Tall & Wide Toggles Style: Circuit Breaker Lockout
Excelente
Reviewed in the United States on May 12, 2026 by IMAICOR
    • Will not fit every breaker
Size: Standard Single and Double Toggles Style: Circuit Breaker Lockout
Doesn't fit all breakers despite being adjustable. I purchased this for a specific panel box and it was too wide to lock on to any single breaker.
Reviewed in the United States on June 16, 2026 by BLG

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