DFJ-30
Bussmann DFJ-30 Class J full-range high-speed drive fuse, 30 A at 600 Vac / 450 Vdc, with the lowest I2t of any branch fuse.
The DFJ-30 is a Bussmann DFJ Class J full-range high-speed drive fuse rated 600 Vac and 450 Vdc at 30 A. It combines the performance of a high-speed fuse with a standard UL Class J branch circuit package, so a designer can protect the power semiconductors of a variable-speed drive or a controller using readily available Class J blocks, holders and switches. The DFJ has the lowest I-squared-t of any UL branch circuit fuse, which is exactly what is needed to protect diodes, GTOs, SCRs and solid-state relays, and its full-range time-delay behaviour lets it ride through the inrush of a drive start without nuisance opening while still clearing a short circuit fast. The DFJ series runs from 1 A to 600 A, which covers a small drive branch and a large controller with the same part family. Because it fits standard Class J hardware, it simplifies both the panel design and the spare-parts list. Every fuse BeiLuo ships is factory-traceable and includes an import declaration, a certificate of origin and a RoHS compliance file, and mainstream current ratings are normally in stock.
FAE Professional Review
The DFJ-30 is the neat solution for a drive branch: it has the low I-squared-t of a high-speed fuse but fits ordinary Class J blocks and switches, so you protect the semiconductors without special holders. Use it where a full-range Class J branch fuse is required and the drive needs real semiconductor protection.
| Parameter | Value |
|---|---|
| Voltage | 600 Vac / 450 Vdc |
| Current | 30 A |
| Standard | UL Class J |
| Body | Class J blade |
| Clearing | Lowest I2t drive fuse |
Application Circuits
Variable-speed drives
Reference circuits and application schematics for Variable-speed drives are available from our FAE team.
Motor controllers
Reference circuits and application schematics for Motor controllers are available from our FAE team.
Solid-state relay protection
Reference circuits and application schematics for Solid-state relay protection are available from our FAE team.
Need a reference schematic or design review? Our FAE engineers can share verified circuits and layout guidance for this part.
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Alternative Part Numbers
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Frequently Asked Questions
What is the DFJ-30 rated for?
It is rated 600 Vac and 450 Vdc at 30 A in a UL Class J blade body, with the lowest I-squared-t of any UL branch circuit fuse. The DFJ series covers 1 A to 600 A.
Confirm the voltage class and the amp rating against your branch.
Why choose DFJ over a standard Class J fuse?
A standard Class J fuse is not fast enough to protect a power semiconductor. The DFJ combines the low I-squared-t of a high-speed fuse with the Class J package, so it protects the device and still fits standard Class J hardware.
It is the best of both for a drive branch.
Is the DFJ-30 genuine and in stock?
BeiLuo supplies factory-traceable DFJ fuses through Bussmann authorized channels, with import declaration, certificate of origin and RoHS files on every order. Mainstream ratings are normally in stock.
Request a sample to validate on the bench.