Blue Sea Systems HD-Series Heavy Duty On-Off Battery Switch With AFD
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You have 30 days to request a return. All sale items are final sale.
Overview
HD-Series Heavy Duty On-Off Battery Switch With AFD delivers robust, high-current switching for demanding electrical systems. It features up to 600A continuous rating, a one-piece tin-plated copper stud design, and ignition protection with UL listing. The make-before-break selector and AFD capability allow safe operation even while the engine is running, helping protect the alternator.
Key Features
- Up to 600A continuous rating
- Make-before-break contact design
- AFD (Alternator Field Disconnect) capable for switching while running
- One-piece tin-plated copper studs that resist loosening over time
- Ignition protected and UL Listed
Compatible Applications
- Marine electrical systems
- Diesel engine installations with high-current battery switching
- Heavy-duty battery switching in industrial or off-road applications
- Systems requiring make-before-break motor/engine control connections
Product Details
- SKU: 661-3001
- Cranking Rating 30 sec.: 1750A DC
- Cranking Rating 1 min.: 1325A
- Intermittent Rating 5 min.: 900A
- Continuous Rating: 600A
- Terminal studs accept 1/2'' or M12 ring terminals
- One-piece tin-plated copper stud design
- Ignition protected
- UL Listed
- AFD (Alternator Field Disconnect) models allow switching while running the engine without damaging the alternator
Parts Desk Insights
Best Use Case: Best use case: switching large battery circuits in high-current marine or diesel installations where engine running does not require interruption of alternator field connections.
Common Issues: Common issues: ensure correct torque on terminal studs, use compatible ring terminals (1/2'' or M12), and avoid exceeding the continuous current rating to prevent overheating.
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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.