Class R and H (K) knifeblade fuse blocks - 250 V

RM Class R and HM Class H(K) modular knifeblade fuse blocks from 100 to 600 amps

Modular 70 to 600 amp 250 volt Class R and H(K) knifeblade fuse blocks with optional covers and blown fuse indication.

Blocks dovetail together to assemble required number of poles.

Optional covers provide additional safety and indication feature speeds troubleshooting. See product broachure no. 3192 for details.

Product profile no. 3196

Product brochure no. 3192

250 V and 600 V 30, 60, 100, 200, 400 and 600 A RM blocks data sheet no. 10489

Product line overview video

Drawing downloads (PDF, DXF/DWG, IGS, STEP)

Catalog Number HM25100-(poles)CR (70 to 100A), HM25200-(poles)CR (110 to 200A), HM25400-(poles)CR (225 to 400A), HM25600-(poles)CR (450 to 600A)
Volts 250V
Fues Amp Range 70A to 600A
SCCR Withstand Rating - Class R 200kA
- Class H(K) 10kA
Poles 1-, 2- and 3-Pole - Dovetail construction permits assembly of poles required by application
Agency Information UL
- Blocks: Listed cULus E14853 – IZLT & IZLT7
- Covers: Listed UL E58836 – JDVS2
- Blocks: Certified 47235 – 6225-01
- Covers: Certified 47235 – 6225-01
Flammability Ratings - Blocks UL 94V0, self-extinguishing
- Covers UL 94HB, self-extinguishing
Conductors - 100A-200A Blocks, 75ºC/90ºC Cu/Al
- 400A-600A Blocks 75ºC Cu/Al
Operating & Storage Temperature Range Blocks
-40ºC to 120ºC
Non-indicating covers -40ºC to 120ºC
Indicating covers -20ºC to 90ºC


  • Integral dovetails allow snapping together multiple poles at point-of-use for greater application flexibility
  • Factory assembled two- and three-pole configurations available
  • Up to four mounting holes per pole increase installation flexibility
  • Standard phase barriers between poles for additional safety
  • Design meets UL creep and clearance requirements for Industrial Control Circuits (UL 508 and UL 845)
  • 200 to 600A blocks meet the higher UL creep and clearance requirements for Industrial Power Distribution Standards (UL 98, UL 69, UL 489, UL 891 and UL 869A)
  • Optional IP20 finger-safe covers available on entire knifeblade fuse block product line:
    • High clarity see-through covers allow for inspecting wire terminations or to take thermography measurements without removing cover
    • Probe holes included for easy, safer testing and troubleshooting
    • Built-in lockout/tagout feature improves safety
  • Standard fuse clip reinforcing springs enhance electrical contact

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