Jabsco 34739 Series Flangemount Blower, 3 in, 150 CFM

Overview

The Jabsco 34739 Series is a flangemount 3 inch marine ventilation blower for moving air in engine rooms, fuel compartments, galleys, heads and other enclosed spaces on board. Each DC model is rated at 150 CFM open-air flow and uses a reinforced plastic housing with corrosion-resistant materials throughout, making it suitable for damp compartments where boat ventilation equipment has to handle moisture, vibration and salt air.

This series uses a bulkhead-mounted outlet flange and a slip-on inlet duct connection for 3 inch ducting. It is mainly used for intermittent ventilation, such as clearing fuel vapors from bilge areas before engine start, while it can also be used for general air circulation where the duty cycle and motor life are acceptable.

Key features

• 150 CFM open-air flow for air intake or extraction in engine spaces, fuel compartments, bilges, galleys, heads and accommodation areas.
• Flangemount outlet lets the blower mount to a flat bulkhead surface for a clean duct run to the discharge vent.
• Slip-on inlet connection accepts 3 inch ducting, helping installers route the pickup hose toward the lower bilge area where vapors collect.
• DC versions comply with USCG electrical regulations, ISO 8846 Marine for ignition protection and ISO 9097 Marine.
• Reinforced plastic housing and corrosion-resistant materials suit humid compartments where bilge moisture and salt air are present.
• Available in 12 VDC and 24 VDC versions so the blower can match the vessel's DC electrical system.

Variants

The 34739 Series is offered in two DC voltage configurations. The mounting style, 3 inch duct connection, 150 CFM airflow class and 5 lb weight are the same across the DC versions, while current draw and fuse size change with voltage.

• 34739-0010: 12 VDC version with 6.5 amp draw and a 10A fuse rating. This version suits boats with a 12 VDC ventilation circuit and should be wired with stranded copper wire sized for the run length.
• 34739-0020: 24 VDC version with 3.3 amp draw and a 5A fuse rating. This version fits 24 VDC systems while keeping the same flangemount format and 3 inch ducting layout.

Installation and wiring

Mount the blower on a flat bulkhead surface in the high part of the compartment, away from direct spray, deck wash and heat above 130°F or 55°C. The installation calls for a 2-3/4 inch cutout and No. 10 screws with washers; the screws should be tightened evenly so the flange is not distorted.

For DC wiring runs up to 25 ft from the power source, use 12 gauge stranded copper wire for the 12 VDC model and 14 gauge stranded copper wire for the 24 VDC model. Longer runs call for larger wire, and the circuit should be protected with the fuse size matched to the selected voltage version.

Use on board

For fuel vapor ventilation, route the inlet duct with as few bends as practical toward the lower third of the bilge or compartment, while keeping the pickup above bilge water and below the top of the engine stringers. This keeps the duct where vapors are likely to settle without placing it where it can be submerged.

This blower is a good match for boat owners replacing a 3 inch flangemount blower or adding powered ventilation to a compartment that needs a DC blower with ignition protection. It is not the right choice for underwater locations or areas where the housing will be repeatedly hit by spray or deck wash.