Fuse JJN (Class T) 400 Amp
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You have 30 days to request a return. All sale items are final sale.
Protect demanding DC electrical circuits with a fast-acting Class T fuse designed for high-amperage electronics equipment. Ideal where quick short-circuit interruption helps safeguard equipment such as inverters.
Key Features
- Fast short circuit response helps protect high amperage electronics equipment such as inverters.
- 20,000 Amp Interrupt Capacity (AIC) UL rated for DC applications under UL189L.
Intended Use
- High-amperage DC power distribution circuit protection (fuse protection for inverter-type systems and other demanding DC loads).
- Use with Class T fuse blocks/fuse holders intended for Class T fuses.
Product Details
- Fuse type: Class T
- Fuse designation: JJN
- Rated current: 400 Amp
- Interrupt rating: 20,000 Amp (AIC)
- UL rating: UL189L (DC applications)
- Part / SKU: 661-5121
Parts Desk Insights
Best Use Case: Best suited for DC circuits where rapid short-circuit protection is important—commonly in inverter and other high-capacity DC power setups that use Class T fuse protection.
Common Issues: If a fuse keeps opening, confirm the circuit load/inrush characteristics and inspect wiring and connections for loose/overheating contacts. Also verify the fuse block/fuse holder is specifically rated for Class T fuses and matches the intended fuse rating.
Related Products & Accessories
- Fuses - Browse Class T fuse blocks and related fuse protection components to match this fuse to the correct holder.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.