Parallax FB11 11-Circuit Fuse Block

The Parallax FB11 provides a separate 12V DC fuse distribution point for RV electrical systems that do not already include a suitable DC load panel. It has 11 fused branch positions and three common, non-fused positive supply terminals. This guide shows what each group does and how to distinguish an FB11 from the fuse panel included with a MagneTek 6345 converter upgrade.

FB11 12V power distribution at a glance

12V positive distribution

Converter or suitably protected battery feedSource and wire protection sized for the installed RV system

Three common positive terminalsNon-fused supply points; these terminals share one positive electrical bus

11 individual branch fuse positionsEach protects its own appropriately sized DC load circuit

#1#2#3#4#5#6#7#8#9#10#11

Circuits shown as numbers only; actual fuse ratings are determined by each connected circuit, not by its position in this illustration.

12V negative return

RV 12V appliancesExamples include lighting, roof fans or a water pump on appropriately protected circuits

Negative return terminal barSeparate from the positive fuse and supply connections

Battery / converter negativeConnected according to the manufacturer's wiring label and RV electrical design

The FB11 distributes and protects branch circuits. It is not a battery charger or an AC shore-power breaker panel.

Original functional diagram for identifying parts, not a physical terminal-location drawing or wiring instructions. Identify the supply lugs, numbered circuits and negative bar on the actual unit before work.

FB11 fuse, wire and enclosure details

Part of assembly	What it does	Selection detail
11 DC fuse positions	Individually protect 12V branch circuits	Standard blade-style fuses; 20A DC maximum per branch position, subject to the connected circuit's permitted fuse rating
Three common positive terminals	Accept appropriately protected converter/battery positive connections	Non-fused terminals; manufacturer's FB-series guidance lists 2–14 AWG conductors
Branch-circuit terminals	Connect the load-side positive wiring	FB-series terminal range is 12–16 AWG; wiring and fuses must be sized together
Negative terminal bar	Provides separate low-voltage return connections	Never treat the negative bar as a fourth positive supply terminal
Metal chassis and hinged lid	Encloses the DC circuit positions	FB11 product listing specifies that fuses are not included and there is no fuse-failure status indicator

Important: The 20A rating is a maximum for an individual branch fuse position, not an instruction to install 20A fuses in every location. Always use the fuse rating appropriate to each circuit's conductor and equipment.

FB11 versus the 6345RU fuse panel

The FB11 is a separate fuse-distribution product for a suitable system without a built-in panel. The Parallax 6345RU is a converter upgrade for a MagneTek/B-W 6345 and comes with the required replacement DC distribution board, including blown-fuse indication. Matching 11 positions alone does not establish that their boards can be exchanged.

FB11 panel and related converter product photos

Start with the FB11's own listing. The 4445 and 4455 are separate deckmount converter examples; any combination requires the proper DC distribution and wiring design. The 6345RU is shown to clarify the different retrofit kit, not as an FB11 substitute.

Catalog image of Parallax FB11 11-position RV DC fuse block

Parallax FB11 11-Circuit DC Fuse PanelSeparate 12V fuse distribution assembly with covered chassis; the product listing specifies no fuses included.View product and current availability

Parallax 4445 45-amp standalone RV converter catalog photo

Parallax 4445 45A Deckmount ConverterStandalone converter/charger example; AC/DC installation and fuse distribution must be designed for the RV.View product and current availability

Catalog photograph of Parallax 4455 55-amp deckmount RV converter

Parallax 4455 55A Deckmount ConverterStandalone 55A charger. FB-style panels serve systems without built-in DC distribution; no installation kit is implied.View product and current availability

Parallax 6345RU converter upgrade kit listing image, distinct from FB11 fuse panel

Parallax 6345RU 45A Converter Upgrade KitDifferent application: MagneTek/B-W 6345 retrofit kit supplied with its own required DC fuse panel.View product and current availability

Parallax manufacturer information

See the manufacturer's FB-series fuse-panel overview for common supply terminals and branch limits, plus specifications for the 4445 converter, 4455 converter and 6345RU upgrade.

Electrical safety: Disconnect shore power, generator, inverter and battery supplies before service. Have a qualified RV electrician select conductor sizes, source protection, fuse ratings, mounting and connections based on the equipment's actual wiring label.

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Parallax FB11 RV Fuse Panel: 11-Circuit Diagram & Parts