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Glass and ceramic fuses both protect circuits the same way: the internal element melts during an overcurrent and opens the circuit. The real difference is what happens in the split-second after the element opens, especially during short-circuit faults (high current, high energy), where arcing and fault containment become the whole game.OptiFuse carries both styles across <a href="https://www.optifuse.com/fuses/electronic-glass-ceramic-fuses-39/">common tube-fuse</a> sizes (3.6×10mm, 5×15mm, 5×20mm, 6.3×32mm, and more).Choose a glass fuse when fault current is low/moderate and you want easy visual inspection (clear body). Choose a ceramic fuse when you might see higher fault current / higher energy and you need better arc-quenching and higher breaking capacity.

<h2>Glass vs. Ceramic Fuse Comparison</h2>

<h2>Ceramic Fuses and Interrupt Rating</h2>
 
Ceramic construction is mechanically stronger and typically uses sand filling to quench arcing and raise interrupt capability.
The key specification that determines this performance is the fuse interrupt rating (breaking capacity) — a rating many people overlook until something fails violently.
Interrupt rating (breaking capacity) is the maximum fault current a fuse can safely clear at its rated voltage. It is not the same thing as the fuse’s amp rating. See our <a href="https://www.optifuse.com/blog/choose-a-tube-fuse/">tube-fuse selection guide</a> for more core electrical ratings to verify.
 
<h3>Why it matters</h3>
When a fuse opens under a high-energy fault, an arc can form across the melted gap. If the fuse can’t quench that arc, it may not clear cleanly. This can create overheating, damage, or (worst case) rupture.
 
<h3>A concrete OptiFuse example (same size, very different outcomes) </h3>
A lot of designers assume “5x20mm is 5x20mm.” The form factor between two fuse types can be the exact same, but electrically, their ratings can differ substantially.
<ul>
<li><a href="https://www.optifuse.com/fuses/electronic-glass-ceramic-fuses-39/250/">FSD</a> (glass, fast-acting, 5×20mm):</li>
</ul>
Interrupting rating listed as 35A or 10×In at 250VAC (whichever is larger).
<ul>
<li><a href="https://www.optifuse.com/optifuse_ecommerce_tools/datasheets/FCD.pdf">FCD </a>(ceramic, fast-acting, 5×20mm):</li>
</ul>
Interrupting rating listed as 1500A @ 250VAC (and additional higher ratings shown for specific conditions/models).
See our <a href="https://www.optifuse.com/blog/fcd-fuse-applications/">FCD Fuse for Delicate Electronics blog </a>for more information.

<h2>What’s physically different inside?</h2>

<h2 class="p2">Substitution rule of thumb</h2>

OptiFuse’s <a href="https://www.optifuse.com/blog/choose-a-tube-fuse/">How to Choose a Tube Fuse</a> guidance emphasizes checking nominal current, voltage, and interrupt rating (and in pulse-heavy cases, I²t). <a href="https://www.optifuse.com/blog/optifuse-fuse-selection-guide/">See our Fuse Selection Guide for complete context</a>.

<a title="Original URL:
https://www.optifuse.com/sebastian-castaneda-optifuse-profile/

Click to follow link." href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.optifuse.com%2Fsebastian-castaneda-optifuse-profile%2F&amp;data=05%7C02%7Craniahc%40triadcomponentsgroup.com%7Cba4e1817de2442d45b0108de581a194c%7C4e4d40c7a6d94d2aa01f5c29a5888588%7C0%7C0%7C639045066773787451%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&amp;sdata=%2FNcWZzVi1NVAQA6q3nXS%2FHx0HIdg4xkZw1w3Op%2FsecY%3D&amp;reserved=0" data-outlook-id="2169bcb2-fb9b-4fd1-9c49-5a04847fe53c">Sebastian Castañeda</a> is a circuit protection specialist and technical writer with application-focused experience in technical support and custom protection design. He contributes practical, application-driven insights to the OptiFuse Blog.

Glass vs. Ceramic Fuses: Key Differences, Interrupt Ratings, and When to Use Each

Glass vs ceramic tube fuses: learn how body material affects arc-quenching and interrupt rating, plus when it’s safe to substitute.

Glass vs Ceramic Fuses: Differences, Interrupt Ratings & Selection

https://cms.optifuse.com/uploads/2026/02/FSD-FCD-01-scaled.jpg

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Oihane Fernandez de Retana

High-current accessory and auxiliary circuits can get expensive fast when something goes wrong. Winches, compressors, inverters, lift gates, and battery feeds all need protection that can survive vibration, moisture, and real-world wiring.The OptiFuse <a href="https://www.optifuse.com/circuit-breakers/high-amperage-heavy-duty-circuit-breakers-44/303/">351 Series</a> is a heavy-duty, waterproof high-amperage circuit breaker commonly used in RVs, marine craft, emergency vehicles, and heavy-duty trucks. It is often installed close to the battery as a primary source of power protection, and the elongated body makes it easier to land heavy-duty lugs.

<ul>
<li class="p2">Current range: 25A to 300A</li>
<li class="p2">Reset type: Type I (automatic reset)</li>
<li class="p2">Ingress rating: IP67 sealed construction</li>
<li class="p2">Terminations: 3/8-16 stud terminals for ring lugs</li>
</ul>

Up to 48VDC, with interrupt ratings listed on the datasheet (including 3000A @ 30VDC and 1500A @ 48VDC).

<ul>
<li class="p2">Auto reset is useful when the breaker is not easy to reach, since it resets after cooling once the fault clears.</li>
<li class="p2">Sealed housing helps in wet, dusty, and splash-prone installs.</li>
<li>The published interrupt rating is positioned to meet ABYC requirements for certain battery main protection scenarios.</li>
</ul>

The 351 is commonly used for high-current DC branches and battery-adjacent protection such as:
<ul>
<li>RV and marine battery feeds / auxiliary distribution</li>
<li>Winches, compressors, hydraulic pump motors, lift gates</li>
<li>DC inverters and high-current accessory distribution</li>
<li>Emergency / fleet vehicle add-ons where sealing + durability matter</li>
</ul>

A few practical details help keep high-amp installs reliable:
<ul>
<li>Mount close to the source (often near the battery) to minimize the length of unprotected cable.</li>
<li>Use properly sized ring lugs on the 3/8”-16 studs, and torque within the manufacturer guidance (stud torque and mounting torque are called out on our 351 <a href="https://www.optifuse.com/optifuse_ecommerce_tools/datasheets/351.pdf">datasheet</a>).</li>
<li>Provide strain relief so the cable weight/vibration isn’t loading the studs.</li>
<li>Route and protect the cable against chafe (loom/grommets) and keep it away from high-heat sources.</li>
</ul>

Need help selecting the right protection for your circuit? <a href="https://www.optifuse.com/blog/optifuse-fuse-selection-guide/">See our Fuse Selection Guide for complete context</a>.

Discover more 

351 High Amp Circuit Breaker: IP67 Auto Reset Protection from 25A to 300A

OptiFuse 351 is a sealed IP67 Type I auto-reset circuit breaker for high-current DC branches. Rated up to 48VDC, 25A to 300A, with 3/8-16 studs.

351 High Amp Circuit Breaker: IP67, 25A to 300 | OptiFuse

https://cms.optifuse.com/uploads/2026/02/351-scaled.jpg

If you’re adding an accessory circuit in a vehicle or DC system, an in-line fuse holder is the cleanest way to put protection where it belongs: right in the harness. The OptiFuse <a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/automotive-blade-fuses-4/in-line-fuse-holder-5/15/">LPM-01</a> is a compact in-line holder for Mini blade fuses with an integrated snap-on cover and an IP65 rating, making it a strong fit for automotive and marine wiring where splash, dust, and vibration are expected.

<ul>
<li class="p2">
Fuse type: Mini blade (use with OptiFuse ANM / APM Mini fuses)
</li>
<li class="p2">
Voltage rating: 125 VDC
</li>
<li class="p2">
Ingress protection: IP65 (snap-on cap)
</li>
<li class="p2">
Current capability: up to 30 A, depending on wire gauge
</li>
<li class="p2">
Leads: UL1015 stranded pigtails, 4 in each side
</li>
<li class="p2">
Temperature range: -40°C to +85°C
</li>
</ul>

<ul>
<li>Saves space versus adding a separate fuse block.</li>
<li>Keeps the fuse serviceable while helping protect the fuse cavity from water and airborne contaminants.</li>
<li>Wire-gauge options let you match the holder to the branch circuit current (don’t overspec the fuse if the pigtails are smaller).</li>
</ul>

If you need the holder to match a harness standard, LPM-01 supports configurable options including:
<ul>
<li>Wire gauge: 12 / 14 / 16 / 18 AWG</li>
<li>Wire colors: Red, Yellow, Orange, Black</li>
<li>Packaging: Bulk or blister pack</li>
</ul>
For additional details, please refer to the <a href="https://www.optifuse.com/blog/in-line-fuse-holder-customization/">In-Line Fuse Holder Customization Guide</a>.
For custom inquiries, please contact our factory team at <a href="http://sales@optifuse.com">sales@optifuse.com</a>

Pair it with the OptiFuse <a href="https://www.optifuse.com/fuses/automotive-blade-fuses-35/193/">ANM-UL Mini blade fuse</a> family (2A–30A, 32 VDC, 1000A interrupt rating) for common automotive branches, or select the Mini fuse that matches your system requirements.
Need a quick refresher on best practices? Follow OptiFuse’s <a href="https://www.optifuse.com/blog/how-install-in-line-fuse-holder/">step-by-step guide on how to install an in-line fuse holder</a>, then size the fuse using nominal current, voltage, and available fault current. <a href="https://www.optifuse.com/blog/optifuse-fuse-selection-guide/">See our Fuse Selection Guide for complete context</a>.

LPM-01 In-Line Mini Fuse Holder: IP65 Protection for Clean Harness Add-Ons

OptiFuse LPM-01 is an IP65 in-line Mini blade fuse holder rated up to 125VDC and up to 30A by wire gauge. Built for automotive and marine harness installs.

LPM-01 IP65 Mini Blade Fuse Holder | OptiFuse

https://cms.optifuse.com/uploads/2026/02/LPM-01-scaled.jpg

Available Fault Current (AFC), often called prospective short-circuit current, is one of the most important numbers in power distribution and industrial electrical design.If you design, build, install or maintain electrical equipment (switchboards, panelboards, industrial control panels, machinery, HVAC equipment, battery/inverter systems, etc.), AFC is a baseline value you must know at the point of installation. It directly impacts:<ul><li>Protective device selection (fuse / breaker interrupting rating)</li><li>Equipment ratings (SCCR, withstand capability)</li><li>Code compliance and inspection readiness</li><li>Safety (fault containment, arc-flash risk reduction)</li></ul>AFC is the maximum current that could flow during a short-circuit at a specific location in the system, typically evaluated at the line terminals of equipment.

AFC isn’t a single “building value.” It changes from point to point as you move through the electrical system because impedance (resistance + reactance) increases as you go downstream.
When engineers estimate or calculate AFC, they typically account for:
1. Utility / source strength
The upstream supply capability (utility transformer size, service capacity, and available fault contribution.
2. Transformers
kVA rating and % impedance (%Z) are major drivers of how much fault current is available on the secondary.
3. Conductors and bus
Feeder length, conductor size/material, and routing all add impedance and reduce available fault current downstream
4. Motors and generators (fault contribution)
Rotating equipment can contribute additional short-circuit current, especially for “close-in” faults near motor control centers

During a bolted fault, current rises extremely fast. If your overcurrent protective device (OCPD) can’t safely interrupt the available fault current, the result can be catastrophic: ruptured devices, equipment damage, arc-flash escalation, fire, and serious injury.

<ul>
<li>Available Fault Current (AFC): The prospective short-circuit current available at a specific point (often at the line terminals of equipment).</li>
<li>Interrupting Rating (IR) / AIC (Amperes Interrupting Capacity): For fuses and circuit breakers, the maximum fault current the device can safely interrupt at its rated voltage.</li>
<li>SCCR (Short-Circuit Current Rating): For equipment/assemblies (like industrial control panels), the maximum fault current the equipment can withstand under defined conditions without unacceptable damage. Please see our <a href="https://www.optifuse.com/blog/sccr-guide-industrial-panels/">Introduction to SCCR</a> article for more information.</li>
<li>Current-Limiting Protection: A fuse (and some protective devices) that reduces let-through energy: both peak current and I²t, helping downstream components survive a fault.</li>
</ul>

At the point of installation, you’re always checking the same relationship:
<hr />
Protective device interrupting rating must be ≥ AFC
OCPD AIC/IR ≥ Available Fault Current (AFC)
<hr />
Equipment SCCR must be ≥ AFC at its line terminals (as applied)
Equipment SCCR ≥ Available Fault Current (AFC)
<hr />
 
If either of those is not true, the installation is at risk and often non-compliant.

Common ways AFC is established:
<ul>
<li>Utility-provided available fault current at the service point (often available by request)</li>
<li>Short-circuit study (engineering calculation using system data)</li>
<li>Onsite field verification of configuration + nameplate data (then calculation)</li>
</ul>
For industrial sites, the most reliable path is usually a short-circuit study that reflects actual operating modes (normal, generator, tie closed, etc.).

Sometimes the available fault current at a facility is simply high (large service, close to a transformer, low-impedance feeders). In those cases, the most practical way to protect lower-rated downstream components is current-limiting protection. Reducing peak let through and I²t that downstream devices experience during a fault.
A classic SCCR “save” is upgrading feeder protection from a less current-limiting option to a current-limiting Class J <a href="https://www.optifuse.com/fuses/industrial-and-ul-fuses-63/523/">T6J</a> fuse so downstream components see dramatically less let-through energy during the fault event.
 
Where OptiFuse industrial fuses fit:
Branch Circuits with inrush (control transformers, solenoids, small motors):
Class CC time delay (<a href="https://www.optifuse.com/fuses/industrial-and-ul-fuses-63/296/">TPK-R</a>) helps ride through startup surge while still providing current-limiting short-circuit protection.
Higher-performance feeder:
Class J (e.g OptiFuse T6J) is commonly used when you need strong current-limiting behavior to help downstream components stay within their SCCR during a high-AFC fault.

Need a quick refresher on fuse clases (CC, J, T, RK5) and where they&#8217;re used: See our <a href="https://www.optifuse.com/blog/industrial-fuses-types-protection/">Industrial Fuses article</a> to learn more about the types of protection classes. <a href="https://www.optifuse.com/blog/optifuse-fuse-selection-guide/">See our Fuse Selection Guide for complete context</a>.

Available Fault Current (AFC): What It Is, Why It Matters, and How to Apply It

Learn what Available Fault Current (AFC) is, what drives it, and how to apply it to interrupting ratings (AIC), SCCR, and current-limiting protection.

Available Fault Current (AFC) Explained: AIC, SCCR & Safety

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If you’re new to sizing and applying fuses, start with our <a href="https://www.optifuse.com/blog/optifuse-fuse-selection-guide/">Fuse Selection Guide</a>. In just a few minutes, it walks you through the core principles you’ll see throughout this article.A fuse is your last line of defense against burnt wiring, damaged gear, and fires. In RVs, where 12 VDC and 120 V AC often live side-by-side, matching the right fuse type and location keeps faults from turning into costly disasters. In some locations, resettable high-amp circuit breakers are used instead of fuses, but they follow the same basic rules: protect the wire, clear faults quickly, and keep energy contained.RVs pack a lot of electrical gear into a small, mobile space: batteries, inverters, solar, slide motors, fans, pumps, and all the creature comforts of a tiny home on wheels. Long, unoptimized wire runs, vibration, and DIY add-ons all increase the chances of a short-circuit or overload—making proper fuse protection essential for preventing damage and ensuring system safety.Explore our <a href="https://www.optifuse.com/doc-for-web/Catalog/OptiFuse-for-Recreational-Vehicles.pdf">OptiFuse for Recreational Vehicles catalog</a> to find fuses and circuit breakers designed for reliable, durable protection in every RV system.

In this article, we’ll focus on 12V DC fusing—the components that protect your batteries and 12V distribution.

<h2>1. Common RV Fuse Types (What to use, and where)</h2>

<img decoding="async" src="http://cms.optifuse.com/uploads/2026/01/Blade-Size-Group-white-background.png" />
<a href="https://www.optifuse.com/fuses/automotive-blade-fuses-35/">Blade fuses</a> are the most common fuse found in RVs. They’re popular because they’re compact, inexpensive, and easy to diagnose at a glance. If the link is melted, you see it within seconds.
<ul>
<li>Use blade fuses for low to mid-current RV circuits: lights, fans, USB/aux ports, control circuits, and small pumps.</li>
<li>Pair them with covered blade fuse blocks so labels stay tidy and roadside diagnostics are quick.</li>
<li>OptiFuse has all sizes available:
<ul>
<li>MICRO 3 Style | MICRO2 Style</li>
<li>Mini Style | Mini Style – Low Profile</li>
<li>Regular (ATO/ATC Style)</li>
<li>Maxi Style</li>
</ul>
</li>
</ul>

Class T fuses range from 1 to 1200 A at 300 VAC / 160 VDC and are very fast-acting with a high interrupt rating, making them ideal for applications where battery banks and inverters can deliver huge fault currents. With silver-plated blades for corrosion resistance and fast short-circuit response, OptiFuse’s Class T Fuses are excellent candidates for inverter and battery protection in demanding RV systems. See <a href="https://www.optifuse.com/fuses/industrial-and-ul-fuses-63/495/">F3T</a> Class T fuses for more detail.
<img decoding="async" src="http://cms.optifuse.com/uploads/2026/01/Class-T-Fuses.png" />
To mount these fuses in an RV, OptiFuse offers Class T fuse blocks designed around real-world marine/rv installs:
<a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/industrial-and-ul-fuses-64/fuse-block-68/517/">BLT3-200</a> mounts 110A-200A fuses
<a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/industrial-and-ul-fuses-64/fuse-block-68/518/">BLT3-400</a> mounts 225A-400A fuses
When paired with an F3T fuse, both blocks are ignition-protected and include an insulating cover that meets ABYC requirements. Each features a four-stud layout, making it easy to connect batteries, inverters, and bus bars without fighting for space.

In the same current ranges as MIDI/MEGA/ANL fuses, many RV builders use high-amp circuit breakers for certain loads:
<ul>
<li>Typical range: roughly 25-300A, depending on breaker style</li>
<li>Common RV uses slide-out motors, leveling jacks, tongue jacks, winches</li>
</ul>
 
<h3>Why choose a breaker instead of a fuse?</h3>
<ul>
<li>Automatic reset, modified reset, manual reset capabilities available</li>
<li>Can double as a local disconnect in a pinch</li>
<li>Easy to troubleshoot in the field</li>
</ul>
See OptiFuse’s <a href="https://www.optifuse.com/circuit-breakers/high-amperage-heavy-duty-circuit-breakers-44/">high-amp circuit breakers page</a> for more information.
 
<img decoding="async" src="http://cms.optifuse.com/uploads/2026/01/High-Amps.png" />
 
<h3>Key things to watch:</h3>
<ul>
<li>DC voltage rating: Make sure the breaker’s DC rating meets or exceeds your system voltage (12/24/48VDC), not just the AC rating on the label. </li>
<li>Interrupt rating (AIC): Just like fuses, high-amp breakers must be able to safely interrupt worst-case fault current that can be seen by the breaker</li>
<li>Continuous rating: Many thermal breakers can run warm at their respective rating. Treat their “30 A” or “100 A” rating like a continuous rating and size wiring and loads accordingly.</li>
<li>Environment and mounting: Stud-type and panel-mount breakers need secure mounting and strain-relieved cables; vibration and heat can impact long-term performance.</li>
</ul>

This article focuses on fuses first, since they set the baseline for overcurrent protection. In many well-designed RV systems, you’ll see a mix of bolt-on fuses for main battery / inverter feeds and high-amp breakers where reset capability and visual status are helpful.

<h2>2. How to Size an RV Fuse</h2>
 
1. Start with the wire
Choose a fuse rating at or below the wire’s ampacity. The fuse’s primary job is to protect the conductor, then the equipment.
 
2. Account for continuous load
For loads running 3+ hours (fans, fridges), target ~125% of continuous current so nuisance openings are minimized.
 
3. Check voltage &amp; interrupting rating (AIC)
DC arcs are stubborn, especially with big lithium banks or large inverters. Verify the fuse has a DC voltage rating that meets or exceeds system voltage and a sufficient interrupt rating for worst-case fault current.
 
4. Choose form factor &amp; holder type
Match the environment: vibration (bolt-on), serviceability
Match the mechanical environment:
<ul>
<li>High vibration, high current: bolt on fuses and stud-type breakers or blocks</li>
<li>Serviceable low currents: blade fuses in organized fuse blocks</li>
</ul>

<h2>3. Placement That Actually Protects</h2>
 
Fuse every positive conductor leaving the battery bank
Main feed, inverter feed, DC-DC charger feed, solar/controller feed, each should have its own fuse or breaker mounted as close to the battery as practical.
 
Keep unprotected lengths short
Aim to minimize the length of the cable between the battery and the first overcurrent device. Where you can’t, add abrasion protection, loom, or conduit in tight runs under floors, through walls, or near metal edges.
 
Fuse sub-panels and branch circuits appropriately
Main DC fuse -&gt; sub panel -&gt; properly sized branch fuses for each load. This keeps fault energy localized and simplifies troubleshooting.

<h2>4. Selecting the Appropriate Fuse Holder</h2>
 
Once you’ve chosen a fuse, match it with a holder suited to the location, environment, and service needs:
 
<h3>In-line fuse holders:</h3>
<ul>
<li>Small form-factor, great for single-circuit branch protection near the load or source</li>
<li>Ideal for add-on accessories, 24-hour “always-hot” circuits, and simple retrofits</li>
<li>See OptiFuse’s <a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/automotive-blade-fuses-4/in-line-fuse-holder-5/23/">LPR-02</a>, <a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/automotive-blade-fuses-4/add-a-fuse-6/19/">LPM-08</a>, <a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/automotive-blade-fuses-4/in-line-fuse-holder-5/36/">LPX-02</a></li>
</ul>
 
<h3>Fuse blocks/panel-mount:</h3>
<ul>
<li>Allow for centralized distribution, easier labeling and troubleshooting</li>
<li>Options for clear insulating covers, LED blown-fuse indication, split buses, and ground buses</li>
<li>See our <a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/automotive-blade-fuses-4/fuse-block-8/429/">BLR-I-504</a>, <a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/automotive-blade-fuses-4/fuse-block-8/404/">BLC-106-G</a>, <a href="https://www.optifuse.com/fuse-holders-blocks-and-accessories/automotive-blade-fuses-4/fuse-block-8/451/">BLR-I-1212-G</a></li>
</ul>
 
<img decoding="async" src="http://cms.optifuse.com/uploads/2026/01/Fuse-Holder.png" />

RV Fuses Explained: How to Protect Your Camper’s 12VDC Electrical System

Explore RV fuse basics, sizing, and placement. Learn about blade, MIDI, MEGA, ANL, Class T fuses, and high-amp breakers for safer RV systems.

OptiFuse RV Fuses: Protect Your Camper’s Electrical System

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When your design outgrows standard blade fuses (ATO/ATC, Mini, Micro), the next bottleneck is usually high-current branch protection: blowers, pumps, heated seats, trailer circuits, and other loads that live in the 20A-60A range.That’s where the <a href="https://www.optifuse.com/fuses/automotive-link-fuses-36/226/">FMX Automotive Link Fuse</a> comes in. OptiFuse’s FMX series is a JCASE-style, female-terminal cartridge fuse designed for higher-current automotive/DC circuits. They’re color-coded for quick amp identification and built with a top window for fast blown-fuse checks.

OptiFuse FMX (JCASE) is specified with:
<ul>
<li>Voltage rating: 32VDC</li>
<li>Current rating: 20-60A</li>
<li>Interrupting rating: 1000A @ 12VDC</li>
<li>Testing standard: ISO 8820-4</li>
</ul>

Think of the FMX/JCASE as the “sweet spot” when your circuit is too large for small blade formats, but you still want compact packaging and easy service.
FMX fuses are perfect for circuits that need high-current branch protection without the bulk of larger cartridge fuses.
To learn how to select the fuse, see our <a class="Hyperlink SCXW238887953 BCX8" href="https://www.optifuse.com/blog/optifuse-fuse-selection-guide/" target="_blank" rel="noreferrer noopener">Fuse Selection Guide</a> for complete context.