Blue Sea Systems ST CLB Circuit Breaker Block 12 Position with Negative Bus

The Blue Sea Systems ST CLB Circuit Breaker Block solves the classic tradeoff between fuses and breakers: it uses compact, snap-in-place CLB resettable circuit breakers that install as easily as a fuse, so you get the reset-without-a-spare convenience of a breaker without the bulk or cost of a panel-style breaker bank.

Key features

• 12 positions, 100A total / 32A per circuit, 32V DC maximum
• Integrated negative bus (#10-32 stud) eliminates a separate ground terminal block
• Quick-connect clips snap breakers into place
• Clear insulating cover with square-format label recesses satisfies ABYC/USCG requirements
• Optional push-button waterproof boots or dress nuts fit over the cover

Because the negative bus is built in, this block is a common upgrade for boats adding several new circuits at once — bilge pumps, cabin lighting, electronics — without running a separate ground wire for each. It pairs with Blue Sea's snap-in CLB breakers from 3A to 40A (PN 7050 through 7061), so a single block can mix breaker ratings across its 12 positions to match each circuit's actual load.

If a position goes unused or needs to bridge two circuits to a common source, the ST CLB Circuit Breaker Block Jumper (PN 5049) snaps in the same way a breaker does. Mount the block in a dry, protected location — a WeatherDeck switch-only panel is a common companion for boats that also want waterproof switching alongside this resettable protection. A dedicated jumper (PN 5049) is also available if you want to bridge a position to the common bus without installing an actual breaker there — handy for reserving capacity for a circuit you plan to add later without leaving the position electrically dead.