Blue Sea 70A 187-Series Surface Mount Thermal Circuit Breaker
Blue Sea 70A 187-Series Surface Mount Thermal Circuit Breaker
Ignition Protected Up to 48V DC with 5/16" (M8) Studs & Manual Reset

DESCRIPTION
Heavy-Duty 70A Overcurrent Protection for Marine and Off-Grid DC Systems
The Blue Sea 187-Series 70A Surface Mount Thermal Circuit Breaker delivers dependable overcurrent protection and manual switching in a single, compact unit. Engineered specifically for demanding marine, automotive, and off-grid DC electrical installations, this breaker protects your wiring and equipment from damaging overloads and short circuits. Supporting DC systems up to 48V DC (covering standard 12V, 24V, and 48V battery configurations), it provides a robust safeguard for main feeder lines, high-draw appliances, and auxiliary battery banks.
Certified Ignition Protection for Harsh Environments
When installing electrical components in enclosed spaces or aboard petrol-powered vessels, safety is critical. This 187-Series circuit breaker is fully ignition protected, meaning it is designed to prevent internal sparks from igniting surrounding flammable vapours. This makes it safe for installation inside petrol engine compartments, battery boxes, and bilge areas on boats, as well as in custom 4WD canopies and caravan power systems where gas or fuel vapours may be present.
High-Torque Connections and Clear Status Indication
Unlike standard low-grade alternatives that suffer from voltage drop, heat build-up, or premature nuisance tripping, Blue Sea Systems builds the 187-Series for maximum conductivity and longevity. The housing features heavy-duty 5/16" (Approx. M8) terminal studs that easily accommodate large-gauge cable lugs and support high-torque connections, minimising electrical resistance under continuous 70A loads. A prominent yellow manual reset lever provides an immediate visual indication of the circuit status and allows you to manually trip and isolate the circuit during maintenance or emergencies.
- 70A Thermal Protection: Safeguards heavy-duty DC circuits across 12V, 24V, and up to 48V DC architectures.
- Ignition Protected: Certified safe for installation in petrol engine compartments and enclosed marine environments.
- Heavy-Duty Terminals: Robust 5/16" (Approx. M8) studs accept large ring terminals for secure, high-torque connections.
- Manual Reset & Isolation: Visible yellow lever clearly displays tripped status and enables manual circuit disconnection.
- Simple Surface Mounting: Pre-drilled mounting holes allow straightforward installation onto flat panels, bulkheads, or distribution boards.
Application Guidelines and System Integration
The surface-mount footprint makes this unit straightforward to integrate into custom power distribution panels in caravans, camper trailers, boats, and service vehicles. While the manual trip lever allows for convenient system isolation during servicing, please note an important operational exclusion: do not use this circuit breaker as a regular on/off switch where high inrush currents are expected, as repeated switching under heavy surge loads can degrade the internal thermal mechanism over time.
Secure Your DC Electrical System
Upgrade your marine, RV, or off-grid power distribution setup with reliable circuit protection. Add the Blue Sea 187-Series 70A Thermal Circuit Breaker to your build today for safe, durable, and compliant DC power management.
SKU: BS-7141B
SPECIFICATIONS
| Specification | Value |
|---|---|
| Component subtype | Thermal circuit breaker |
| Mounting / form factor | Surface mount |
| Ignition protected | Yes |
| Terminal size | 5/16 M8 |
| SKU: | BS-7141B |
| Model #: | BS-7141B |
| MPN: | BS-7141B |
| Package weight: | 0.36 kg |
| Package length: | 0.1 m |
| Package width: | 0.09 m |
| Package height: | 0.08 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.

