Furuno PR-240 AC-DC 24VDC Marine Power Supply Unit

FURUNO PR-240 AC-DC 24VDC Marine Power Supply Unit

The FURUNO PR-240 is an AC-to-DC power rectifier engineered to power GMDSS radio consoles, commercial radar processors, ECDIS systems, and vessel automation networks. Manufactured by FURUNO Electric Co., Ltd. in Nishinomiya, Japan, this unit converts single-phase AC shipboard mains (100–115 VAC or 200–230 VAC nominal at 50/60 Hz) into a stabilized 24 VDC output capable of delivering up to 10 A continuous load.

The PR-240 uses a linear step-down transformer paired with solid-state regulation, front-panel thermal-magnetic circuit breakers, and relay-actuated AC/DC changeover circuitry. When shipboard AC mains fail or drop below critical thresholds, the internal changeover relay automatically switches connected critical electronics over to an external 24 VDC emergency battery bank without interrupting bridge navigation feeds.

Technical Details

Features

1. Dual-Input Field Selection: Configurable internal primary transformer taps allow operation on 100–115 VAC or 200–230 VAC single-phase 50/60 Hz shipboard mains.
2. Automatic Emergency DC Changeover: Integrated changeover relay switches the output load to a 24 VDC reserve battery during AC mains loss with negligible changeover transient.
3. Dual Protection: Includes a 5 A primary AC breaker (CB-2) and a 12 A secondary DC circuit breaker (CB-1) for fault isolation.
4. Low RF Interference: Linear-regulated architecture minimizes conducted and radiated electromagnetic emissions around sensitive bridge equipment (MF/HF, VHF, AIS, GPS).
5. Industrial Marine Enclosure: Heavy-gauge chassis with anti-corrosion marine finish and pre-punched bulkhead mounting slots.

Compatible Marine Systems

• Furuno GMDSS Systems: Inmarsat-C Felcom-15 / Felcom-18, Navtex Receiver NX-700A/B, MF/HF and VHF Radiotelephone bridge units.
• Radar & Plotting Systems: FAR-2117 / FAR-2127 / FAR-28xx series radar processor sub-assemblies, FR-8062, FR-8125.
• ECDIS & Sensor Concentrators: FMD-3100, FMD-3200, FMD-3300 processing modules, HUB-3000 intelligent networks.
• AIS & Navigation Aids: FA-150 / FA-170 / FA-70 Class-A/B AIS transponders, SC-50 / SC-70 / SC-130 Satellite Compasses.
• Echo Sounders & Sonars: FE-700 / FE-800 Navigation Echo Sounders, FCV-1200, FCV-1900 fish finding systems.

Applications

• Bridge Navigation Consoles: Clean 24 VDC power rail for critical GPS, gyro repeaters, and bridge alarm management (BAM) panels.
• Emergency GMDSS Radiocommunications: Seamless automatic transition from ship’s primary generator to emergency battery distribution under SOLAS Chapter IV requirements.
• Commercial Retrofit Projects: Direct replacement for legacy Furuno PR-series or failing bridge rectifiers in deep-sea, tug, crew-transfer, and commercial fishing vessels.

Frequently Asked Questions

Can the Furuno PR-240 accept both 115 VAC and 230 VAC?

Yes. The PR-240 supports 100–115 VAC and 200–230 VAC single-phase 50/60 Hz inputs. Input selection is set internally via transformer wire taps and a jumper block. Always confirm this setting matches vessel supply voltage before energizing.

How does the emergency battery changeover function on the PR-240?

The PR-240 has dedicated input terminals for an external 24 VDC emergency battery bank. When AC line voltage drops out, internal sensing circuitry de-energizes the main transfer relay, instantly switching the DC load to the battery line without dropouts on navigational displays.

What is the maximum continuous current capacity of the unit?

The unit provides a continuous output of 10 A at 24 VDC. It is equipped with a 12 A DC front-panel breaker (CB-1) to protect against sustained over-current conditions.

How does the older PR-240 compare to the newer PR-241?

The PR-240 utilizes a heavy-duty, low-noise linear transformer design, while the PR-241 uses a high-efficiency switch-mode power topology. Both are rated for 24 VDC output with automatic battery switchover, but the PR-240 is often preferred in retrofit situations where RF emission must be kept to an absolute minimum.