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Blue Sea 225 to 400A Class T Fuse Block Holder w/ Insulating Cover
Blue Sea 225 to 400A Class T Fuse Block Holder w/ Insulating Cover
Clear safety cover, tin-plated copper blocks, 160V DC rated
Key features: Maximum current capacity of 400A, Clear insulating cover for safe operation, Tin-plated copper mounting blocks for high conductivity, Four 3/8 inch (M10) terminal studs, Base material resistant to high heat.
Highlights:M10 Terminal Studs: High-torque 3/8 inch (M10) stainless steel studs for secure cable connections,Tin-Plated Copper Blocks: Provides maximum conductivity and corrosion resistance in marine environments,Secure Mounting Holes: Four corner holes accept 1/4 inch (M6) screws for stable installation.
Perspective view demonstrating the installation of a Class T fuse between the tin-plated copper blocks and M10 studs. Note: Fuse is sold separately.
End profile view showing the height clearance of the protective snap-on cover over the 3/8 inch terminal studs.
Installed Blue Sea Class T Fuse Block protecting a high-current circuit with heavy-duty battery cabling and safety cover secured. 
Regular price
$90.00
Availability:
In Stock
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DESCRIPTION
High-current Class T fuse protection for inverters, battery banks and DC systems
When you’re running high-demand equipment such as inverters, DC-DC chargers or large battery banks, the protection device needs to handle serious fault current without becoming the weak link. The Blue Sea Class T Fuse Block Holder is built for 225–400A Class T (JJN) fuses and is commonly used in marine, caravan, 4WD and off-grid power systems where reliable, fast-acting overcurrent protection matters.
Class T fuses are valued for their high interrupt capacity and rapid response to short circuits—particularly important in lithium battery and high-power inverter installs where fault currents can rise extremely quickly. This fuse block helps you implement that protection in a clean, serviceable way, with robust electrical contacts and a layout designed for heavy cabling.
Safer installs with a clear insulating cover
The included clear insulating cover reduces the risk of accidental contact with live terminals while still allowing quick visual checks during inspection and maintenance. It’s also designed to help meet ABYC/USCG expectations for covered battery and DC distribution connections—useful for marine compliance and for anyone building a professional-grade installation.
Built to handle heat, vibration and real-world loads
High-current connections generate heat when they’re not engineered properly. This holder uses tin-plated copper mounting blocks to support efficient conductivity and corrosion resistance, helping reduce contact losses that can lead to hot terminals. The hardware and stud format are well suited to secure cable lugs, making it a solid option for demanding environments such as engine bays, battery compartments and power cabinets.
Designed for modern DC power systems (up to 160V DC)
With suitability up to 160V DC, this fuse holder supports more than just 12V setups. It can be used in 24V and 48V systems commonly found in marine and off-grid installations, and is a practical choice when you want consistent protection architecture across different battery voltages. Selecting the correct fuse rating remains important—this holder is compatible with the fuse range, while system design should consider expected continuous current, surge loads and installation conditions.
Key features
- Accepts Class T (JJN) fuses from 225A to 400A (fuse sold separately)
- Clear insulating cover helps prevent accidental contact and supports compliant installs
- Tin-plated copper blocks for conductivity and corrosion resistance
- 3/8"-16 stud terminals suit heavy-duty lugs (up to 4/0 AWG)
- 160V DC capable for 12V, 24V and 48V DC system architectures
Where this fuse block fits best
This Blue Sea fuse holder is often selected as a main battery fuse close to the positive terminal, or as dedicated protection for a high-current inverter. It’s also ideal when upgrading from smaller fuse styles where interrupt ratings and physical robustness may be limiting factors.
Note: This is the holder only; the Class T fuse is purchased separately so you can choose the amperage appropriate for your cable size, load profile and manufacturer recommendations.
Build a safer, cleaner high-current DC system
If you’re wiring a serious inverter or battery bank and want a professional fuse mount with an insulating cover and high-current terminals, add this Blue Sea Class T fuse block to your build and pair it with the correct Class T fuse for your system.
SPECIFICATIONS
Specifications
| Ignition Protected | No |
|---|---|
| Maximum Amperage | 400A |
| Maximum Voltage | 160V DC |
| Fuse Mounting Blocks | Tin-Plated Copper |
| Maximum Cable Size |
4/0 AWG (AWG to mm² varies by strand class/standard; reference only) |
| Maximum Torque |
190 in-lb (21.47 N·m) (approx. 15.8 ft-lb; reference only) |
| Mounting Holes |
Accept 1/4" (M6) Screw (1/4" ≈ 6.35 mm; M6 is 6 mm; reference only) |
| Terminal Stud Size |
3/8" - 16 (M10) (3/8" ≈ 9.53 mm major diameter; M10 is 10 mm; 16 TPI ≈ 1.59 mm pitch; reference only) |
| Weight (min / max) |
1.10–1.10 lb (0.50–0.50 kg) (approx. 500 g; reference only) |
| SKU: | BS-5502B |
| Model #: | BS-5502B |
| MPN: | BS-5502B |
WARRANTY
Blue Sea Warranty Policy
Blue Sea Systems products sold by us are supplied with a warranty against defects for the warranty period shown below, subject to the product type, application and the terms of this warranty policy.
The express warranty provided by us is limited to a maximum of 5 years from the original date of purchase, unless otherwise required under Australian Consumer Law.
Blue Sea Systems may offer longer manufacturer support on some products at their discretion
Warranty Lengths by Product Range
| Blue Sea Product Range | Warranty Length | Application / Notes |
|---|---|---|
| Most Blue Sea Systems Products | 5 years | Applies to most Blue Sea Systems products found to be defective in materials or manufacture. |
| P12 Battery Chargers | 5 years | Warranty period starts from the original date of purchase. |
| P12 Remote Displays | 5 years | Warranty period starts from the original date of purchase. |
| Digital Meters | 3 years | Warranty period starts from the original date of purchase. |
| Vessel System Monitors | 3 years | Warranty period starts from the original date of purchase. |
Warranty Assessment and Remedy
If a Blue Sea Systems product is found to be defective in materials or manufacture within the applicable warranty period, we will, at our discretion, arrange a repair, replacement, store credit or refund, depending on the nature of the fault and the requirements of Australian Consumer Law.
Products may need to be returned for assessment before a warranty claim can be approved. Where required, the product must be returned with dated proof of purchase and a clear description of the fault.
Labour costs for removing, replacing, reinstalling or diagnosing a product are not covered by this express warranty unless otherwise required under Australian Consumer Law.
Making a Warranty Claim
To make a warranty claim, please contact us with your dated proof of purchase, product details and a description of the fault.
The product may need to be returned for inspection before the claim can be assessed. If the product is confirmed to be faulty and covered by this warranty, we will advise the available remedy.
What This Warranty Does Not Cover
This warranty does not cover faults or damage caused by incorrect installation, incorrect application, misuse, abuse, neglect, unauthorised modification, accidental damage, normal wear and tear, environmental damage, or failure to use the product in accordance with the manufacturer's instructions.
- Incorrect installation or wiring
- Incorrect product selection or application
- Misuse, abuse or neglect
- Physical or accidental damage
- Water ingress or environmental damage outside the product's intended use
- Unauthorised modification or repair
- Normal wear and tear
- Labour costs for removal, replacement, reinstallation or diagnosis
- Freight, travel or call-out costs unless otherwise required by law
- Products not returned for assessment when reasonably required
Manufacturer Support
Blue Sea Systems may provide additional manufacturer support on some products beyond the warranty period listed above. Where available, we may assist customers in contacting the manufacturer, but any manufacturer support beyond the express warranty period is subject to the manufacturer's own terms and continued availability.
Australian Consumer Law
This warranty is in addition to other rights and remedies available at law. Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.
