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Mersen A6T60 Class T Fast-Acting Fuse, 60A 600VAC/300VDC Ferrule
Model: MER-A6T60
Mersen A6T60 Class T Fast-Acting Fuse, 60A 600VAC/300VDC FerruleThe Mersen A6T60 Class T Fast-Acting Fuse delivers reliable overcurrent protection rated 60A for both 600VAC and 300VDC applications...
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Mersen A6T20 Class T Fast-Acting Fuse, 20A 600VAC/300VDC
The Mersen A6T20 is a Class T fast-acting fuse rated 20A for both AC and DC electrical systems, delivering dependable overcurrent protection at 600VAC and 300VDC. Built with copper ferrule terminals and GMG body insulation, this fuse is engineered for a 200kA breaking capacity, giving it exceptional fault-current interruption for demanding commercial and industrial circuit protection applications. Its compact clip-mount design and rapid fast-acting response make it a reliable choice for professionals who need code-compliant, space-efficient overcurrent protection.
Key Features
- 20A Current Rating: Provides precise overcurrent protection for medium-load circuits and equipment protection applications.
- 600VAC/300VDC Dual Voltage: Versatile voltage compatibility enables reliable use in both AC and DC electrical systems.
- 200kA Breaking Capacity: Exceptional fault-current interruption capability ensures safe protection even under high fault conditions.
- Class T Fast-Acting Response: Rapid fault detection and interruption minimizes equipment damage and enhances system safety.
- Ferrule Terminal Design: Copper ferrule terminals provide secure, low-resistance connections for reliable electrical contact.
- GMG Body Insulation: Professional-grade insulating material ensures electrical isolation and mechanical durability in service.
- Clip Mounting System: Convenient mounting method allows for quick installation and replacement in fuse holders and panels.
Technical Specifications
- Body Insulating Material: GMG
Typical Applications
- Commercial and Industrial Panel Protection
- Motor Control Centers and Switchgear
- Power Distribution Systems
- HVAC Equipment Protection
- Lighting and Control Circuits
- Renewable Energy Systems
- Emergency Power Applications
Why Mersen?
Mersen Class T fuses deliver proven reliability with professional-grade GMG body insulation and copper ferrule terminals for secure, low-resistance connections. The compact clip-mount design combines a fast-acting response with an exceptional 200kA breaking capacity, giving electrical professionals a space-efficient, code-compliant solution for protecting critical AC and DC circuits in commercial and industrial installations.
Manufacturer Resources
Mersen Product Catalog
Product Specs
- Product Type:
- Fast-Acting Fuse
- Product Material:
- GMG
- Connection Type:
- Ferrule
- Voltage Rating:
- 600VAC/300VDC
- Amperage Rating:
- 20A
- Department:
- Electrical
- Product Group:
- Circuit Protection
- Product Subgroup:
- Fuses
- Product Length:
- 1.5 in
- Product Weight:
- 0.03 lb
Mersen A6T20 – Frequently Asked Questions
1) Can the Mersen A6T20 Class T fuse be used on a DC circuit, like a solar or battery system?
Yes. The A6T20 carries a dual rating of 600VAC and 300VDC, so it protects DC circuits up to 300 volts as well as AC circuits up to 600 volts. Stay within the 300VDC figure on the DC side, it is lower than the AC rating and it is the one that governs battery and PV applications.
2) Will a 20A Class T fuse fit my existing fuse block, or do I need a specific holder?
The A6T20 has ferrule terminals and mounts in clips, so it needs a fuse block or holder made for Class T ferrule fuses at 20A and 600V. Class T bodies are dimensionally specific to the class and amp band, and they are not interchangeable with Class CC, midget, or J blocks. Match the block to Class T, 600V, 0-30A.
3) Does the A6T20 have enough interrupting rating for a high fault-current service panel?
200kA breaking capacity, which covers service entrance and switchgear locations where available fault current is high. That is the figure to check against the fault current calculation on your drawing, and it is well above what molded case breakers in the same enclosure typically carry.
4) Is a Class CC time-delay fuse an acceptable substitute for a Mersen A6T20 Class T fuse?
No, they are different classes with different bodies and different response curves. The Mersen A6T20 is a Class T fast-acting fuse rated 20A at 600VAC/300VDC with ferrule terminals. The Littelfuse CCMR040 is a Class CC time-delay fuse rated 40A. Class T and Class CC fuses are not dimensionally interchangeable, so a CCMR will not seat in a Class T clip or block, and the time-delay curve is intended to ride through inrush rather than clear as quickly as the fast-acting A6T20. Use a time-delay Class CC where a motor or transformer inrush would nuisance-open a fast-acting fuse, and match the holder to the class you choose.
5) What is the difference between the Mersen A6T20 and a midget fast-acting fuse like the Littelfuse BLF?
Both are fast-acting, but they are built for different system voltages and fault levels. The Mersen A6T20 is a Class T fuse rated 20A at 600VAC/300VDC with a 200kA breaking capacity and copper ferrule terminals in a GMG insulating body. The Littelfuse BLF is a midget fast-acting fuse rated 250V in a laminated tube. For a 600V commercial or industrial panel, motor control center, or switchgear circuit, the A6T20 is the one that carries the voltage rating; a 250V midget belongs on control and low-voltage branch circuits. The two use different holders and are not drop-in interchangeable.
6) I need 600V fuses for a metering circuit, not a feeder. Is the A6T20 the right choice?
Probably not, if you are fusing the potential leads of an energy meter. The Mersen A6T20 is a 20A Class T fuse at 600VAC/300VDC sized for branch and feeder overcurrent protection in panels, motor control centers, and power distribution. Meter voltage taps draw almost no current and are protected at a much lower amperage: the Square D PowerLogic energy meter fuse pack is a set of three rated 0.5A at 600V for exactly that duty. Use the low-amperage meter fuses on the metering PTs and reserve the A6T20 for the load circuit it is sized to protect.
7) Why choose a Class T fuse over a glass tube or midget fuse for panel protection?
Size and fault handling. Class T is a compact, high interrupting capacity fuse intended for commercial and industrial panels, motor control centers, and power distribution, at 600VAC with a 200kA breaking capacity. Glass tube types like the Littelfuse AGA or AGU series, and midget types like the Littelfuse BLF at 250V, are low voltage control and electronics fuses and do not belong in a 600V distribution circuit.
8) What part number do I order to standardize 20A Class T protection across a facility?
Order Mersen A6T20. The A6T prefix is the 600V AC Class T family and the trailing number is the amp rating, so a 20 amp unit is A6T20. Keeping the same designation across panels means one spare part number on the shelf for every 20A Class T position rated 600VAC/300VDC.
9) Can I use a glass tube fuse such as the Littelfuse AGU or AGA in place of a Mersen A6T20?
No. The Littelfuse AGU and AGA series are AG glass tube fuses, with the AGA5 rated 5A; they are small glass-body cartridge fuses used for accessory, audio, and low-energy circuits. The Mersen A6T20 is a Class T fuse rated 20A at 600VAC/300VDC with a 200kA breaking capacity, clip-mounted with copper ferrule terminals, and intended for commercial and industrial panel, power distribution, and HVAC equipment protection. A glass tube fuse has neither the physical form nor the fault-current interruption duty of a Class T fuse and will not fit a Class T fuse block.
10) Which fuse should I stock for a DC circuit at 300V or less?
The Mersen A6T20 carries a dual rating of 600VAC/300VDC, so it is the one that covers DC service such as renewable energy and emergency power circuits as well as AC panels. Among the alternatives, the Littelfuse BLF midget is rated 250V and the Littelfuse CCMR040 is a Class CC time-delay device; neither is listed with the dual AC/DC rating the A6T20 carries. If the circuit is DC up to 300V and needs fast-acting protection at 20A, the A6T20 is the fit.
11) What is the A6T20 fuse body made of, and will it hold up in a hot panel?
The body is GMG insulating material with copper ferrule ends. GMG is a molded glass-melamine type insulating body used for mechanical strength and electrical isolation in service, paired with copper ferrules for a low-resistance contact in the clips.
12) Can I use the A6T20 in an HVAC disconnect or a lighting control circuit?
Yes, within its ratings. Typical uses for this fuse include HVAC equipment protection, lighting and control circuits, power distribution, emergency power, and renewable energy systems. The limits to respect are 20 amps, 600VAC or 300VDC, and a fast-acting curve that will not tolerate sustained inrush.
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Does the Mersen A6T20 come with a warranty?
Absolutely. The Mersen A6T20 is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
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