Bennett Marine offers a range of trim tab solutions designed to enhance boat performance, stability, and fuel efficiency. Trim tabs are essential components for fine-tuning a vessel’s attitude in the water, particularly during high-speed operation or in rough seas. This article provides a comprehensive overview of Bennett trim tab installation procedures, system operation, and troubleshooting guidance based on official manufacturer documentation.
Trim tab systems can be either hydraulic or electric, with electric models offering streamlined installation and control options. The Bennett AutoTrimPro, BXT, and SLT Self-Leveling Tabs are among the most commonly installed systems, each offering unique features tailored to different vessel types and user preferences. This guide outlines the key steps for installing Bennett trim tabs, including control unit placement, wiring procedures, and initial system calibration.
Installation Overview for Bennett Trim Tab Systems
Bennett trim tab systems are designed for ease of installation while maintaining high durability and performance. The installation process varies slightly depending on the model—whether it is an electric or hydraulic system—and the control interface selected (e.g., rocker switch, single-lever, or digital keypad).
For electric trim tab systems such as the Bennett AutoTrimPro, the installation involves positioning the tabs on the transom, mounting the control unit, and connecting the wiring harnesses. Hydraulic systems, including the SLT Self-Leveling Tabs, require additional steps for actuator installation and fluid line routing.
A critical step in the installation of any Bennett trim tab system is the proper calibration and setting of the "Zero Point," which establishes the baseline attitude for the boat. Without this step, the Auto Tab Control (ATC) system cannot function correctly.
Pre-Installation Considerations
Before beginning the installation, it is essential to assess the vessel’s specific requirements and the intended use of the trim tab system. Key factors include:
- Vessel Size and Weight: Larger vessels may require larger tabs to effectively correct for trim issues.
- Boat Speed: The effectiveness of trim tabs increases with speed. At lower speeds, the impact of trim adjustments is minimal.
- Engine Configuration: Sterndrive and outboard engines may require different tab mounting positions to optimize performance.
- Control Preferences: Users can choose between manual control via a rocker switch or automatic control through the ATC system.
Proper planning ensures that the trim tabs are installed in the most effective location and that the control system is configured to meet the user’s needs.
Positioning and Mounting Trim Tabs
Trim tab positioning is critical for optimal performance. The tabs should be mounted as far outward as possible on the transom, with the inner edge at least 2 inches from a strake edge and the outer edge 1 to 4 inches from the chine. For the Lenco Marine 12-by-12-inch Standard Performance tabs used in some Bennett installations, at least 11 inches of transom height is required.
Tabs must be mounted symmetrically on both sides of the transom to ensure balanced operation. The installation process typically involves the following steps:
- Marking and Drilling: Use a tape measure and straightedge to mark the mounting holes. A 2-inch hole saw is used to create the necessary openings.
- Mounting Hardware: Secure the tabs using the provided mounting brackets and sealant to prevent water ingress.
- Wiring and Connections: Connect the tabs to the control system using extension cables and ensure proper polarity.
The use of marine-grade sealants, such as Sikaflex 291, is recommended to maintain watertight integrity around the tab mounting points.
Installing the Control Unit and Keypad
The control unit is the central component of the Bennett trim tab system. It must be mounted in a dry, stable location with minimal vibration. Recommended mounting locations are within 6 feet of the ATC Keypad, as the keypad cable is 6 feet long. The control unit must not be mounted upside down or at an extreme angle, as this can affect the system’s ability to calibrate correctly.
For systems with the ATC Keypad, the Zero Point must be set before the system can function. This involves taking the boat for a test run and manually adjusting the trim tabs to the desired attitude. Once the optimal position is achieved, the "Set Zero" buttons on the keypad must be pressed and held for approximately 4 seconds until the blue LED flashes rapidly.
Wiring and Electrical Connections
Wiring procedures vary depending on the type of trim tab and control system installed. For electric trim tabs, the wiring typically includes a 25-foot wire harness that connects the control unit to the EIC Relay Module. The wire harness must be trimmed to the appropriate length and stripped to prepare for crimping. Color-coded connections must be matched precisely to ensure proper function.
For installations involving the Electronic Indicator Control (EIC5000), a special wire harness is required to link the EIC module to the ATC control unit. The EIC Relay Module includes a dedicated connector for the ATC system, and the wire pigtail must be connected accordingly.
Users who did not purchase the ATC system with the EIC5000 must contact Bennett Marine for the appropriate wire harness. This is a critical step, as failure to use the correct wiring can result in improper system function.
Setting the Zero Point
The Zero Point is the baseline attitude at which the boat should operate under normal conditions. This setting is essential for the ATC system to function correctly. If the Zero Point is not set, the ATC system will not activate, and the blue Zero Set LED will flash.
To set the Zero Point, follow these steps:
- Initial Setup: Ensure that the trim tabs are installed and the control unit is properly mounted.
- Test Run: Take the boat for a test run and use the manual trim tab control to adjust the boat to the desired attitude.
- Set Zero Point: Press and hold both "Set Zero" buttons (Sun and Moon Buttons) on the ATC Keypad for approximately 4 seconds until the blue LED flashes rapidly.
- System Activation: Release the buttons once the LED is flashing. The system will automatically turn off, and the Zero Point is now stored in memory.
This process should be repeated if the boat's attitude changes due to modifications such as engine upgrades or changes in load distribution.
Troubleshooting and Maintenance
Bennett trim tab systems are designed for reliability, but occasional issues may arise. Common troubleshooting steps include:
- System Not Activating: Ensure the Zero Point has been set. If not, the system will not function, and the blue LED will flash.
- Incorrect Trim Adjustments: If the trim tabs frequently cannot correct an out-of-trim position, the tabs may be undersized or the boat speed may be too low.
- Electrical Issues: Verify that all wiring connections are secure and that the correct wire harness is being used for EIC5000 installations.
- Control Unit Malfunction: If the control unit is mounted in a location with excessive vibration or improper orientation, it may fail to calibrate correctly.
Bennett Marine provides detailed troubleshooting guides in their manuals, including diagnostic codes and recommended solutions. Users should consult the appropriate installation and user guide for their specific model.
Compatibility and Integration with Other Systems
Bennett trim tab systems are compatible with a range of marine electronics, including NMEA 2000 backbone systems and electronic indicator controls. For example, the NMEA1 Trim Tab Indicator allows users to monitor the position of the trim tabs in real time via the NMEA 2000 network.
Users who are integrating the trim tab system with other marine electronics should follow the manufacturer's guidelines for wiring and configuration. Special attention must be paid to wire color coding and connector types to ensure proper integration.
Safety and Warranty Information
Safety is a critical consideration during installation and operation. All electrical connections should be made with the battery power disconnected to prevent electrical shock. Additionally, trim tabs should be adjusted gradually to avoid sudden changes in boat attitude that could lead to loss of control.
Bennett Marine provides warranty information for all trim tab systems, covering defects in materials and workmanship. Users should retain their installation instructions and warranty documentation for reference.
Conclusion
Bennett trim tab systems offer a reliable and effective solution for improving boat performance, stability, and fuel efficiency. By following the manufacturer’s installation guidelines, users can ensure that their trim tab system is properly configured and functioning optimally. From positioning the tabs on the transom to setting the Zero Point and troubleshooting common issues, each step is essential for achieving the best results.
Whether using the AutoTrimPro, BXT, or SLT Self-Leveling Tabs, Bennett Marine provides comprehensive support through detailed manuals and customer service. With the right tools, preparation, and attention to detail, boat owners can successfully install and operate Bennett trim tabs to enhance their boating experience.