Mersen 70308 3-Pole Semiconduc...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$176.94
$138.37
Mersen 70308 3-Pole Semiconductor Fuse Block, 750VAC/750VDC 30A

Mersen 70308 3-Pole Semiconductor Fuse Block, 750VAC/750VDC 30A

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Model: 70308

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

$176.94
$138.37
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Mersen 70308 3-Pole Semiconductor Fuse Block, 750VAC/750VDC 30A

The Mersen 70308 3-Pole Semiconductor Fuse Block delivers dependable circuit protection for demanding semiconductor applications with dual 750VAC/750VDC voltage capability and a 30A ampere rating. Built with a thermoplastic body and a reinforced clip-in fuse installation method, this 3-pole fuse block mounts via direct screw mounting and carries a 200 kA short circuit current rating (SCCR) for critical electrical systems. Rated for 50/60 Hz operation and RoHS compliant, this compact block measures approximately 3" x 3" x 1.37" and weighs just 0.38 lb, making it a practical choice for professional installations.

Key Features

  • Dual Voltage Rating: 750VAC/750VDC capability supports both AC and DC semiconductor protection applications.
  • 30A Ampere Rating: Handles substantial current loads while maintaining reliable fuse protection performance, with a 30A max fuse rating.
  • 3-Pole Configuration: Provides complete three-phase circuit coverage for multi-phase semiconductor systems.
  • Reinforced Clip-In Design: Secure fuse installation method helps prevent accidental disconnection during operation or maintenance.
  • 200 kA SCCR: High short circuit current rating delivers robust fault protection in demanding electrical environments.
  • Thermoplastic Construction: Durable insulating body material supports long-term reliability and electrical isolation.
  • Direct Screw Mount: Installation mounting method with a 35 lb-in torque rating for secure, code-compliant connections.
  • 50/60 Hz Rated: Compatible with standard AC power frequencies used in commercial and industrial systems.

Certifications & Compliance

  • RoHS Compliant

Technical Specifications

  • Rohs Compliant: Yes

Typical Applications

  • Semiconductor Equipment Protection
  • Industrial Motor Control Centers
  • Power Distribution Panels
  • Manufacturing Process Equipment
  • Renewable Energy Systems
  • Critical Infrastructure Protection

Why Mersen?

Mersen builds this 3-pole semiconductor fuse block with thermoplastic construction and RoHS-compliant materials for dependable, code-compliant performance in professional electrical work. The 200 kA SCCR and 35 lb-in torque rating support secure, reliable connections, while the compact 3" x 3" x 1.37" footprint and 0.38 lb weight offer flexible installation in panels and control centers where space is limited. Dual 750VAC/750VDC and 30A ratings make this block a versatile choice for semiconductor circuit protection.

Manufacturer Resources

Mersen Product Catalog

Product Specs

Product Type:
Fuse Block
Product Material:
Thermoplastic
Configuration:
3-Pole
Voltage Rating:
750VAC/750VDC
Amperage Rating:
30A
Connection Type:
Clip-In
Standards:
RoHS Compliant
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Fuse Holders & Blocks
Product Weight:
0.38 lb
Product Length:
3 in
Product Width:
3 in
Product Height:
1.37 in
Number Of Poles:
Three-pole

Mersen 70308 – Frequently Asked Questions

1) Can the Mersen 70308 fuse block be used on a DC circuit, like a solar or drive bus?
Yes. The 70308 is rated 750VAC and 750VDC, so it holds the same 750V ceiling on either an AC or a DC circuit. That dual rating is why it shows up on drive front ends, DC links and renewable energy systems as well as standard 50/60 Hz three-phase power.
2) What size fuse does the Mersen 70308 block take, and how many poles?
It is a 3-pole block sized for 30A maximum, so one block covers all three phases at up to 30 amps. Fuses clip in rather than bolt down. Do not put a larger-ampere fuse in it; 30A is the block's ceiling, not a suggestion.
3) Will a 200 kA SCCR fuse block satisfy my panel's available fault current?
The 70308 carries a 200 kA short circuit current rating, which covers the available fault current on essentially any commercial or industrial service you are likely to be feeding a 30A semiconductor circuit from. For panel-build documentation, that 200 kA figure is the number you record against this block.
4) How much room do I need in the enclosure, and how does the Mersen 70308 mount?
Plan on roughly 3 x 3 x 1.37 inches of panel space. It mounts by direct screw fixing to the subpanel, not to DIN rail, so you need tapped holes or a mounting plate behind it. Terminals torque to 35 lb-in.
5) Do I need a semiconductor fuse block, or will a standard Class R block do the job?
They are not interchangeable in intent. The Mersen 70308 is built for semiconductor protection, where fast-acting fuses guard SCRs, diodes and drive rectifiers, and it is rated to 750V on both AC and DC. A general branch-circuit block like the Littelfuse LFR60030-3CID is a Class R block rated 600V 30A, which suits ordinary motor and feeder protection but is a 600V part and takes Class R fuses, not semiconductor fuses. Pick by the fuse class your drawing calls out.
6) Is the Mersen 70308 suitable for a 1000 Vdc PV combiner?
No. The 70308 tops out at 750VDC, so a 1000 Vdc photovoltaic string is above its rating. For that duty look at a purpose-built PV block such as the Bussmann CHPV2 Series, which is a modular two-pole photovoltaic fuse block rated 1000 Vdc. The Mersen is the right part for DC buses at or below 750V.
7) What is the difference between the Mersen 70308 fuse block and the Littelfuse LFR60030-3CID?
Both are three-pole, 30A fuse blocks, but they are built around different fuse classes and voltage ranges. The Mersen 70308 is a semiconductor fuse block rated 750VAC/750VDC with a clip-in fuse connection and a thermoplastic body. The Littelfuse LFR60030-3CID is a Class R fuse block rated 600V at 30A. Class R blocks accept standard Class RK1/RK5 branch and feeder fuses; the Mersen block is designed to hold high-speed semiconductor fuses that protect rectifiers, drives and other solid-state equipment, and its 750VDC rating covers DC circuits above the 600V Class R block.
8) Can I use the Mersen 70308 on the DC side of a solar array?
The Mersen 70308 carries a 750VDC rating alongside its 750VAC rating, so it suits DC circuits up to 750V, and it is a three-pole block. Many PV combiner designs run at 1000 Vdc and use two-pole per-string holders instead; for that case the Bussmann CHPV2 series photovoltaic fuse block is a modular two-pole design rated 1000 Vdc. Match the block to the array's maximum system voltage and to whether you are protecting strings individually or a three-phase circuit.
9) I need a DIN rail mounted fuse block instead of a screw-mounted one. What are my options?
The Mersen 70308 is a direct screw mount block, so it will not snap onto DIN rail. If the panel layout is rail-based, the Littelfuse LFG60015-1SQDINR is a DIN rail mount block, though it is a Class G part rated 600V 15A, so it is a lower voltage and lower amperage device than the Mersen. The Littelfuse LD Series POWR-BLOKS are bolt-in mounting.
10) What part number do I order for the Mersen 3-pole 750V 30A semiconductor fuse block?
The manufacturer part number is 70308, from Mersen. That single number covers the 3-pole, 750VAC/750VDC, 30A clip-in block; there are no finish or size options to specify with it.
11) My panel spec calls for bolt-in fuse mounting. Does the Mersen 70308 meet that?
No. The Mersen 70308 uses a reinforced clip-in fuse installation method, with the block itself fastened by direct screw mounting at 35 lb-in. If the drawing calls for a bolt-in fuse connection, the Littelfuse LD Series POWR-BLOKS fuse block is a bolt-in mounting design and answers that requirement directly.
12) Is a Class R 30A block a drop-in replacement for the Mersen 70308?
It is not. The Littelfuse LFR60030-3CID is also a three-pole 30A block, but it is a Class R block rated 600V and it accepts Class R fuse dimensions. The Mersen 70308 is a semiconductor fuse block with clip-in retention rated 750VAC/750VDC, so the fuse bodies, the voltage ceiling and the intended let-through characteristics all differ. Swapping one for the other changes the protection your solid-state equipment sees, so replace a semiconductor block with a semiconductor block.
13) Which fuse block should I standardize on across a plant with mixed AC and DC equipment?
For circuits at or below 30A where both AC and DC appear, the Mersen 70308 covers both with a single 750VAC/750VDC rating, a 200 kA SCCR and a 3 in. x 3 in. x 1.37 in. footprint. Where the plant has general-purpose 600V AC branch circuits, those are typically Class R or Class G territory, served by blocks such as the Littelfuse LFR60030-3CID at 600V 30A or the Littelfuse LFG60015-1SQDINR at 600V 15A. Standardizing usually means one semiconductor block for drive and rectifier protection and one Class R or G block for conventional feeders rather than one part for everything.
14) Does the Mersen 70308 meet RoHS for our procurement spec?
Yes, the 70308 is RoHS compliant, which is usually what institutional and OEM purchasing needs on record for a control panel component. The body is thermoplastic, which is the insulating material you would list on a submittal.
How fast can I get the Mersen 70308 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 70308 come with a warranty?
Absolutely. The Mersen 70308 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 70308?
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
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