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Approvals & Standards

  • UL Listed, guide IZLT File E52283
  • CSA Certified C22.2, class 6225 01, File 32169
  • IEC certified 60269-1, 60947-3

Key features & benefits

Mersen UltraSafe Modular 600 Volt Fuse Holders for Class J fuses introduce a new level of safety and ease for installing or replacing Class J fuses. UltraSafe holders qualify as “finger-safe” to an IP20 grade of protection under IEC standards. The US3J accommodates 30A Class J or 22 x 58 mm French Ferrule* fuses. The US6J is for 60A Class J fuses. UltraSafe holders are available in compact 1, 2, or 3 pole units, with or without blown-fuse indicators in each pole. Multi-pole units can also be made up in the field by using the multiplepole Assembly Kits. All units have provisions for locking in the open position for safety during fuse changeouts or equipment servicing. US3J and US6J holders can be snap-mounted to 35 mm DIN-rail and they have a unique latch which will stay open to allow re-positioning of the holder in the future. UltraSafe body material is tough and durable polyamide.

  • Holder not UL listed when installed with French Ferrule fuses.
  • US3J, US6J use with AJT, A4J, HSJ
More specifications


  • 600 volt motors, transformers, lighting, heating, control circuits, general loads
  • Non-load disconnect

Product Specifications

Item Number


Item Description (ERP)


Short Description

Fuse Holders 600V 30A Class J 1-pole Neutral No Indicator  



Rated voltage AC UL

600   V

Rated voltage DC UL

600   V

Ampere Rating

30   A

ROHS Compliant


Fuse Class

Class J  

Short Circuit Current Rating (SCCR)

200   kA

Fuse Type/Class

Class J  

Number of Poles


Wiring range

#2 to 14 AWG  

Fuse Installation Method


Body/Insulating Material


Max Fuse Rating

30   A

Installation Mounting

DIN Rail  

Product Weight

0.46   lb

Product Width

1.28   in

Product Length

4.49   in

Product Height

3.15   in

Sell Pack Quantity

6   Each

Sell Pack Weight

2.9   lb

Sell Pack Width

4.8   in

Sell Pack Length

8.27   in

Sell Pack Height

3.43   in