Mersen AJT Series Class J Time...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$59.77
Mersen AJT Series Class J Time-Delay Fuse, SmartSpot Indication

Mersen AJT Series Class J Time-Delay Fuse, SmartSpot Indication

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Model: AJT10

In Stock (leaves warehouse same day if ordered before 3pm ET)

$59.77
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Mersen AJT Series Class J Time-Delay Fuse, SmartSpot Indication

The Mersen AJT Series Class J Time-Delay Fuse delivers reliable circuit protection for commercial and industrial electrical systems. Rated 600VAC/500VDC with up to 200 kA breaking capacity, this blade-terminal fuse series features Mersen's SmartSpot indication system for immediate visual confirmation of fuse status. Built with a GMG insulating body and brass connection terminals, the AJT Series supports current-limiting Class J performance and dimensional standardization across a range of ampere ratings for dependable protection in demanding electrical environments.

Key Features

  • Class J Design: Delivers current-limiting performance and dimensional standardization for reliable system integration.
  • Dual Voltage Capability: 600VAC/500VDC rating offers versatility for both AC and DC power systems.
  • 200 kA Breaking Capacity: Delivers exceptional fault current interruption capability for enhanced system safety.
  • SmartSpot Indication System: Provides immediate visual confirmation of fuse status, reducing troubleshooting time.
  • Time-Delay Characteristic: Allows temporary overloads while providing fast response to fault conditions.
  • Blade Terminal Design: Enables secure clip or bolted mounting for versatile installation options.
  • Durable Construction: GMG insulating body with brass connection terminals for dependable performance.
  • Frequency Rating: Rated for 50/60 Hz power systems for broad application compatibility.

Certifications & Compliance

  • RoHS Compliant

Technical Specifications

  • Refer to manufacturer documentation for complete technical specifications.

Typical Applications

  • Industrial Motor Control Centers
  • Commercial Power Distribution Systems
  • Manufacturing Equipment Protection
  • Data Center Power Infrastructure
  • Healthcare Facility Electrical Systems
  • Educational Institution Power Distribution

Why Mersen?

Mersen fuses deliver proven reliability with RoHS compliant construction and professional-grade materials, including a GMG insulating body and brass connection terminals. The SmartSpot indication system paired with Class J current-limiting design provides enhanced safety and dependable performance for critical electrical protection applications across the AJT Series.

Manufacturer Resources

Product Specs

Product Type:
Fuse
Product Material:
GMG
Voltage Rating:
600VAC/500VDC
Connection Type:
Blade
Standards:
RoHS Compliant
Department:
Electrical
Product Group:
Wiring Devices

Mersen AJT10 – Frequently Asked Questions

1) Will a Mersen AJT fuse fit a Class J fuse block or disconnect switch?
Yes. AJT Series fuses are built to Class J dimensions, which is the whole point of the Class J designation: every Class J fuse of a given ampere range shares a standard body length and blade spacing, so an AJT drops into any Class J block, holder, or fusible switch rated for that amperage. The blade terminals seat in clips or bolt down, depending on how the block is built. Class J is not interchangeable with Class R, Class T, or Class CC, so the block itself has to be Class J rejection type.
2) Will a time-delay Class J fuse hold motor inrush without nuisance blowing?
That is what the time-delay element is for. The AJT tolerates the temporary overload of a motor starting or a transformer energizing, then still clears a genuine short circuit fast because it is current-limiting. If you are protecting a resistive or electronic load with no inrush, a fast-acting Class J is the better match; time-delay on a load that never surges just means a slower clear on overload.
3) What is the interrupting rating on the Mersen AJT fuse, and is it enough for my service?
200 kA. That covers essentially any available fault current you will see downstream of a commercial or industrial service, which is why Class J fuses are commonly used to series-rate or protect equipment with a lower standalone withstand. Combined with the current-limiting action, the AJT cuts the let-through energy the downstream gear actually sees, not just the prospective fault.
4) Can I replace a Class R or Class T fuse with a Mersen AJT?
No, not directly. Class J bodies and blade dimensions are their own standard, and a Class J fuse will not seat in a Class R or Class T holder, nor the reverse. Swapping classes means changing the fuse block or the disconnect's fuse clips, not just the fuse. Within Class J, the AJT replaces another Class J time-delay fuse of the same amp rating one for one.
5) Can a Square D PowerLogic energy meter fuse pack be used in place of a Mersen AJT Class J fuse on a feeder or motor circuit?
No. The Square D PowerLogic energy meter fuse pack is a set of three 0.5A 600V fuses intended for the voltage-sensing leads of a PowerLogic energy meter, and 0.5A carries no load current. The Mersen AJT is a Class J time-delay fuse with blade terminals, rated 600VAC/500VDC, and it runs from AJT8 at 8 amps up to AJT400 at 400 amps for protecting the circuit itself. The two are not interchangeable in either direction: the AJT is the branch or feeder protection, and the meter pack protects the instrument tap.
6) What amp ratings does the Mersen AJT Class J fuse come in?
AJT covers 8, 9, 10, 12, 15, 17-1/2, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 300, 350 and 400 amps. Note the fractional ratings: the 17-1/2 amp is ordered as AJT17-1/2, and the small end (AJT8, AJT9, AJT12) exists specifically for control transformer and small motor branch circuits where a 15 amp fuse is too coarse to hold the overload curve tight.
7) How do I tell if a Mersen AJT fuse has blown without pulling it out of the block?
The AJT carries Mersen's SmartSpot indicator, a visual marker on the fuse body that changes state when the element opens. You read it in place, so troubleshooting a three-fuse set in a disconnect means looking at the indicators rather than pulling all three and meggering them one at a time. That matters most in a motor control center or data center distribution gear where opening the enclosure is the expensive part of the job.
8) I need small fuses for a PowerLogic meter, not a motor circuit. Is the AJT the right thing?
No. The AJT starts at 8 amps and is a Class J power fuse for feeders, motor circuits, and distribution gear. For metering, the Square D PowerLogic Energy Meter Fuse Pack is the matched part, a set of three rated 0.5A 600V, sized for the potential leads on the meter rather than for load current. Fusing a meter input with an 8 amp Class J gives the wiring no meaningful protection.
9) Is the Mersen AJT fuse RoHS compliant for a spec that requires it?
Yes, the AJT Series is RoHS compliant. The body is GMG insulating material with brass connection terminals.
10) Do I have to order Mersen AJT fuses in sets of three for a three-phase circuit?
AJT is ordered by individual ampere rating, one part number per fuse, so a three-phase disconnect takes three of the same number (three AJT60 for a 60 amp three-pole switch, for example). If you are stocking spares for a facility, standardizing on the amp ratings already in your gear is the usual approach, since a single AJT part number covers every Class J holder at that rating.
How fast can I get the Mersen AJT10 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Mersen AJT10 come with a warranty?
Absolutely. The Mersen AJT10 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Mersen AJT10?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Mersen AJT10 from ZenSupply?
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