Jabsco 36740-Series Flexmount 3 in Engine Blower, Universal Bracket, Slip-On Ducting, ISO 8846

Overview

The Jabsco 36740-Series Flexmount 3 in. Blower is a marine ventilation blower for moving air and fuel vapors out of engine compartments and bilge spaces. The series uses 3 inch slip-on ducting connections and is offered for 12VDC, 24VDC, and 115VAC systems, with airflow ratings of 150 CFM on the DC versions and 140 CFM on the AC version.

This Flexmount blower is mainly used for intermittent ventilation work, such as clearing gasoline vapors before engine start-up and helping air move through enclosed machinery spaces. The outlet can be rotated in the bracket, which helps keep duct runs shorter and reduces unnecessary bends when space behind panels or bulkheads is limited.

The series meets USCG Regulation 183.410 and ISO 8846 MARINE for ignition protection. The DC models also comply with ISO 9097 MARINE, making them suitable for properly installed DC bilge ventilation circuits on boats.

Key features

• 3 inch inlet and outlet connections accept slip-on ducting for straightforward hose connection in bilge and engine-compartment layouts.
• Flexmount bracket allows the outlet to face any direction, which helps reduce duct bends on tight bulkhead runs.
• Available in 12VDC, 24VDC, and 115VAC versions to match different onboard electrical systems.
• Airflow is rated at 150 CFM for the DC models and 140 CFM for the AC model.
• Meets USCG Regulation 183.410 and ISO 8846 MARINE for ignition protection; DC models also comply with ISO 9097 MARINE.
• Housing is made from reinforced plastic, with corrosion-resistant materials used throughout the blower.
• N.M.M.A. Type Accepted for marine ventilation applications.

Variants

This blower is offered in three electrical configurations. The main differences are voltage, airflow rating, current draw, and fuse size.

Across the range, the blower keeps the same 3 inch duct connection style, Flexmount bracket layout, reinforced plastic housing, and general installation approach. The correct variant depends on the vessel circuit feeding the blower.

• 36740-0031: 115VAC, 140 CFM airflow, 1.25 A fuse size. This version belongs on an AC blower circuit rather than a 12V or 24V DC house system.
• 36740-0000: 12VDC, 150 CFM airflow, 10 A fuse size. This version matches 12 volt DC blower circuits used on many small and mid-size boats.
• 36740-0010: 24VDC, 150 CFM airflow, 5 A fuse size. This version matches 24 volt DC systems often found on larger vessels and more complex electrical installations.

Installation and wiring

Mount the blower on a flat bulkhead surface in the highest part of the compartment, away from direct spray, deck wash, and heat above 130°F. The inlet duct should run with as few bends as possible toward the lower third of the bilge area, where vapors can collect, while staying high enough to avoid submersion in bilge water.

For DC installations up to 25 ft from the power source, use marine grade copper wire sized for the system: 12 gauge for 12 volt circuits and 14 gauge for 24 volt circuits. Longer runs require larger wire, and the circuit must be protected with the fuse size that matches the selected variant.

For the 115VAC version, use 16 gauge stranded copper wire for runs up to 100 ft from the power source. The grounded conductor connects to the white motor lead, the switched conductor connects to the black motor lead, and the green motor lead connects to the AC circuit ground.

Use on board

This blower is a practical fit for boat owners replacing an existing 3 inch Jabsco Flexmount unit or adding ignition-protected ventilation to a gasoline engine compartment where the installation can meet the required ventilation rules. It can also support general air circulation in spaces such as bilges, accommodation areas, galleys, and heads when the duty cycle is appropriate.

For engine-compartment ventilation, run the blower before starting the engine and check the bilge area for gasoline vapors. This product is not a continuous-duty blower; for applications that require constant operation, a long-life blower category is the more appropriate option.