Mersen 632 Class H & K Fuse Re...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$95.60
$50.66
Mersen 632 Class H & K Fuse Reducer - H & K

Mersen 632 Class H & K Fuse Reducer, 600VAC/600VDC Rated, 50kA SCCR

(No reviews yet) Write a Review

Model: 632

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

$95.60
$50.66
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like

Mersen 632 Class H & K Fuse Reducer, 600VAC/600VDC Rated, 50kA SCCR

The Mersen 632 Class H & K Fuse Reducer allows Class H and K fuse clips to accept smaller fuse sizes, making it a practical solution for fuse panel retrofits and upgrades without replacing the entire fuse block. Rated 600VAC and 600VDC with a short-circuit current rating (SCCR) of 50 kA, this reducer is built for demanding commercial and industrial electrical distribution systems. It is UL Listed and CSA Certified, giving electrical professionals a code-compliant option for adapting existing fuse holders to current fuse specifications.

Key Features

  • Fuse Reduction: Reduces Class H and K fuse clips to accept alternate fuse sizes, simplifying panel upgrades and retrofits.
  • AC Voltage Rating: Rated 600 VAC for use in standard AC power distribution circuits.
  • DC Voltage Rating: Rated 600 VDC, extending suitability to DC electrical systems.
  • Short-Circuit Current Rating: 50 kA SCCR supports use in high fault-current environments.
  • Broad Standards Coverage: Covers 250V and 600V Class H, K, and R applications under UL Listed Guide No. IZZR and CSA Certification, plus 600V Class J under UL Listed status.
  • Certified Construction: Backed by UL Certification E105670 IZZR.E105670 and CSA Certification 6225-01 207417 for verified performance.

Certifications & Compliance

  • UL Listed – Certification E105670 IZZR.E105670
  • CSA Certified – 6225-01 207417
  • UL Listed Guide No. IZZR for 250V and 600V Class H, K, and R
  • UL Listed for 600V Class J

Technical Specifications

  • Ac Voltage: 600 VAC
  • Ce Conformity: Consult Technical Services
  • Csa Certification: 6225-01 207417
  • Dc Voltage: 600 VDC
  • Lead Free: Consult Technical Services
  • Rohs Compliant: Consult Technical Services
  • Sccr: 50 kA
  • Standards: 250V and 600V Class H, K, and R - UL Listed Guide No. IZZR, CSA Certified. 600V Class J - UL Listed
  • Ul Certification: E105670 IZZR.E105670

Typical Applications

  • Fuse Panel Retrofits and Upgrades
  • Commercial and Industrial Electrical Distribution
  • Class H and K Fuse Holder Adaptation
  • Motor Control Centers and Switchgear
  • Maintenance and Replacement of Existing Fuse Blocks

Why Mersen?

Mersen's 632 Fuse Reducer combines a 600VAC/600VDC rating with a 50 kA SCCR and UL/CSA certification to deliver a dependable, code-compliant solution for adapting Class H and K fuse clips. For electrical professionals managing panel retrofits or maintaining legacy fuse blocks, this reducer offers verified performance backed by recognized third-party listings from UL and CSA, supporting safe, code-compliant upgrades in commercial and industrial electrical distribution systems.

Manufacturer Resources

Mersen Product Catalog

Product Specs

Product Type:
Fuse Reducer
Voltage Rating:
600VAC / 600VDC
Listing:
UL Listed
Standards:
CSA Certified
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Fuse Holders & Blocks

Mersen 632 – Frequently Asked Questions

1) What does a Mersen 632 fuse reducer actually do in a fuse panel?
The Mersen 632 lets existing Class H and K fuse clips accept a smaller fuse size. Instead of pulling and replacing the whole fuse block when a circuit gets re-fused down, you drop the reducer into the clips and mount the smaller fuse in it. That is why it shows up most on fuse panel retrofits, legacy fuse block maintenance, motor control centers and switchgear.
2) Is the Mersen 632 reducer rated for DC circuits as well as AC?
Both. It carries a 600 VAC and a 600 VDC rating, so it can be used in DC distribution as well as standard AC power circuits.
3) Can I use this reducer on a circuit with high available fault current?
The 632 carries a 50 kA short-circuit current rating, so it can sit in a panel whose available fault current is up to that figure. Above 50 kA it is not the right part.
4) What is the Littelfuse equivalent to the Mersen 632 fuse reducer?
The closest cross-brand counterpart is the Littelfuse LRUR Series fuse reducer, also sold as the LRU2 Series, which performs the same job of adapting fuse clips to accept a different fuse size. The Mersen 632 is specified for Class H and K clips, is rated 600VAC/600VDC with a 50 kA SCCR, and is UL Listed and CSA Certified. When cross-referencing, match the clip class and fuse ampere sizes at each end of the reducer so the pair seats correctly in the existing block.
5) Does this fuse reducer have third-party certification I can cite for an inspection?
Yes. UL Listed under certification E105670 IZZR.E105670, and CSA Certified under 6225-01 207417. Those are the numbers to put on a submittal for an inspector or facility engineer.
6) Is there an alternative brand of fuse clip reducer if I am standardized on something other than Mersen?
Littelfuse builds the LRUR Series (also referenced as LRU2 Series) fuse reducer as a fuse clip adapter, which is the comparable part from another maker. Specifics beyond the series designation differ by part, so match the voltage class and fuse size you are reducing to when you cross it over from the Mersen 632.
7) Can I avoid replacing an entire legacy fuse block just to change fuse sizes?
That is the point of the 632. For a property manager or MRO group maintaining older Class H and K fuse blocks, the reducer adapts the existing clips to the current fuse specification, so the block, the mounting and the wiring all stay in place during the upgrade.
8) Will the Mersen 632 reducer work in a Class R or Class J holder?
The 632 itself is built for Class H and K fuse clips. Mersen's reducer standards coverage spans 250V and 600V Class H, K, and R under UL Listed Guide No. IZZR with CSA certification, plus 600V Class J under UL Listed status, so confirm the specific model matches the holder class in front of you rather than assuming one reducer covers all of them. The Littelfuse LRUR Series fuse clip adapter is the other-brand option to cross-reference for the same purpose.
9) Do I need to replace the whole fuse block, or will a reducer work?
If the existing block is sound and the only change is fuse size, a reducer is the lighter-touch path. The Mersen 632 lets Class H and K fuse clips accept smaller fuse sizes so a panel can be retrofitted without pulling and rewiring the block, and it is rated 600VAC/600VDC with a 50 kA SCCR. The Littelfuse LRUR Series fuse clip adapter addresses the same situation from the other brand. Replace the block itself when the clips are damaged, the voltage class is wrong for the circuit, or the new fuse is a class the existing block cannot be adapted to.
10) What is the Mersen part number to order for this fuse reducer?
Order it as Mersen 632. That is the manufacturer part number and the only model on the part.
11) Do I need a RoHS or lead-free declaration for the Mersen 632?
RoHS compliance, lead-free status and CE conformity on the 632 are all handled through Mersen Technical Services rather than published as a flat yes or no. If your spec requires a written declaration, request it on the 632 specifically before you submit.
How fast can I get the Mersen 632 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 632 come with a warranty?
Absolutely. The Mersen 632 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 632?
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 632 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
!