Blue Sea 100A 187-Series Panel Mount Thermal Circuit Breaker
Blue Sea 100A 187-Series Panel Mount Thermal Circuit Breaker
Waterproof 48V DC Max - SAE J1171 Ignition Protected - 5/16" M8 Studs

DESCRIPTION
Integrated Manual Switching and Heavy-Duty Overcurrent Protection
The Blue Sea 187-Series 100A Panel Mount Thermal Circuit Breaker delivers a reliable, space-saving solution by combining manual circuit switching and overcurrent protection into a single device. Engineered for demanding 12V, 24V, and up to 48V DC electrical systems, this marine-grade breaker eliminates the need to wire a separate battery switch and fuse holder. It is an ideal component for isolating and protecting high-draw auxiliary circuits in boats, caravans, 4WDs, and off-grid power setups.
Engineered for Harsh Marine and Automotive Environments
Safety is critical when installing electrical components near fuel sources or in damp conditions. This 187-Series thermal breaker is fully ignition protected (meeting SAE J1171 requirements), making it safe for installation aboard petrol-powered vessels and within vehicle engine bays. Its waterproof housing seals out moisture, salt spray, and dust, preventing internal corrosion that commonly causes unbranded breakers to fail prematurely or suffer from nuisance tripping.
Fail-Safe Operation and Heavy-Gauge Terminations
Featuring a high-visibility yellow single-lever actuator, the unit provides immediate visual confirmation of your circuit status whether mounted vertically or horizontally. The internal mechanism features a trip-free design, meaning the circuit will still trip in the event of an overload or short circuit even if the lever is physically held in the ON position. To prevent high-resistance hot spots and voltage drop under heavy 100A loads, the breaker is equipped with robust 5/16" (Approx. M8) terminal studs designed to accommodate heavy-gauge wire lugs and high-torque connections.
- Dual-Function Design: Combines a manual ON/OFF isolation switch with reliable 100A thermal circuit protection.
- SAE J1171 Ignition Protected: Safe for installation in marine engine compartments and petrol-powered boat bilges.
- Waterproof Construction: Sealed enclosure protects internal components against moisture ingress in exposed environments.
- Trip-Free Mechanism: Ensures the circuit cannot be manually held closed during an active electrical fault condition.
- Heavy-Duty Terminals: Large 5/16" (Approx. M8) studs accept heavy-gauge ring terminals for secure, low-resistance connections.
- Flush Panel Mounting: Recessed mounting holes provide a clean, professional finish on switch panels and dashboards.
Application Guidelines and System Integration
This 100A circuit breaker is well suited for protecting main DC feed lines, windlasses, bow thrusters, hydraulic pumps, and dual-battery charging circuits up to a maximum rating of 48V DC. Please note an important operational exclusion: do not use this thermal circuit breaker as a manual switch where high inrush currents are expected, as repeated switching under extreme startup loads can degrade the internal contacts over time.
Upgrade Your DC Circuit Protection
Ensure your high-amperage 12V to 48V DC systems are safely isolated and protected against electrical faults. Add the Blue Sea 187-Series 100A Panel Mount Circuit Breaker to your setup today for dependable, marine-grade performance.
SKU: BS-7044B
SPECIFICATIONS
| Specification | Details |
|---|---|
| Product type | Circuit breaker |
| Mounting / form factor | Panel mount |
| Ignition protected | Yes |
| Actuator type | Manual |
| Terminal size | 5/16 M8 |
| SKU: | BS-7044B |
| Model #: | BS-7044B |
| MPN: | BS-7044B |
| Package weight: | 0.3 kg |
| Package length: | 0.1 m |
| Package width: | 0.08 m |
| Package height: | 0.09 m |
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.

