Operational Overview
Theory of operation:
As loads shift in a boat or as sea and wind conditions change, trim tabs are an important enhancement for a
boat to maintain a level boat and comfortable ride. The Lectrotab auto leveling control (ALC) will
automatically sense changes in lateral or roll (port and starboard) and longitudinal (fore and aft) position and
adjust the tabs to bring the boat level. When sea or wind conditions change, course changes, or passengers
move around the boat, the ALC will automatically adjust the tabs to maintain a proper boat level, eliminating
the need for constant trim tab adjustments from the helmsman.
Control disabled while turning or off plane:
The auto leveling control is designed with built-in gyros to sense when a boat is turning and disables the
control while in a turn or below planing speeds to prevent automatic corrections. The ALC automatically
reverts back to Auto mode once a steady course is sensed or boat is on plane again. The AUTO indicator will
flash while the boat is in a turn or below planing speeds.
Control configured for 20 foot or larger boats:
The auto leveling control system may be configured for boats larger than 20 feet to effectively maintain the
correct boat level. For vessels over 50’ please contact Lectrotab for correct matching of ALC control to
actuators and tabs.
Control adapts to varying sea conditions:
In calm seas, a list condition is corrected faster than in rough seas. This allows for faster tab reaction when
needed and avoids unnecessary tab adjustments in rough seas, which could cause a roll in high waves.
LED Position indicators:
The display will show tab adjustments by lighting LED’s downward for tab deployment and upward for tab
retraction. While automatically adjusting the tabs, the LED indicator, adjacent to the one lit up, will flash to
show adjustment direction.
Automatic and Manual modes:
The auto leveling control may be switched from automatic to manual mode by pressing the AUTO button.
The AUTO LED remains lit in automatic mode. In manual mode, the AUTO LED goes off. The top and bottom
buttons can be pressed to manually control bow down and bow up respectively, and the left and right
buttons can be pressed to manually correct boat listing or roll to bring the port side down (starboard side up)
or starboard side down (port side up), respectively. The AUTO LED indicator flashes to indicate the boat is
turning or is off plane, and the automatic control is disabled during this time.
Adjusting Gain for faster response time:
The gain on the ALC can be adjusted for a faster response time to correct listing from starboard or port sides
in the automatic mode. Review ALC programming section of this manual.
Automatic Tab Retraction:
The trim tabs will automatically retract when the ignition key or accessory switch is switched off.
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