Chamberlain LIFTMASTER SL920 User Manual
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CIRCUIT BOARD:
The SL920 uses the Full Systems Capability circuit board, a powerful control
system. This circuit board operates on 12 ~ 18 Volts and can deliver power to the motor through high
power switching. The limit switch input terminals require the use of normally open type limit switches.
These switches are used to accurately stop the gate operator in the open and closed positions. To
safeguard the operator from damage that could result from limit switch or system protection failure, the
Full Systems Capability circuit board has a built-in maximum run timer which will allow the operator to run
for approximately 300 seconds and then shut off automatically. The Full Systems Capability circuit board
has an adjustable gate sensitivity feature which will stop or reverse the gate if the gate is pushing harder
than normal because of an obstruction.
GATE SENSITIVITY:
The SL920 Full Systems Capability circuit board has a built-in system
protection feature which when adjusted properly will deliver only enough power to the motor to overcome
the resistance of the gate. The amount of power that the circuit board will deliver can be adjusted for both
directions of travel to accommodate the various gate weights that the SL920 operator is recommended
for. (See Applications Pg. 3)
Vehicular Gate Operator Classes:
Class I - Residential Vehicular Gate Operator: A vehicular gate operator (or system) intended for use in a home of
one-to four single family dwellings, or a garage or parking area associated therewith.
Class II - Commercial/General Access Vehicular Gate Operator: A vehicular gate operator (or system) intended for
use in a commercial location or building such as a multifamily housing unit (five or more single family
units), hotel, garage, retail store, or other building servicing the general public.
Class III - Industrial/Limited Access Vehicular Gate Operator: A vehicular gate operator (or system) intended for use
in an industrial location or building such as a factory or loading dock area or other locations not intended
to service the general public.
Class IV - Restricted Access Vehicular Gate Operator: A vehicular gate operator (or system) intended for use in a
guarded industrial location or building such as an airport security area or other restricted access location
not servicing the general public, in which unauthorized access is prevented via supervision by security
personnel.
Gate Operator model SL920 is intended for Vehicular Gate Operator Classes I, II, III, and IV.
Gate Inspection:
a) Install the gate operator only when:
1) The operator is appropriate for the construction of the gate and the usage Class of the gate,
2) All openings of a horizontal slide gate are guarded or screened from the bottom of the gate to a minimum
of 4 ft. above the ground to prevent a 2-1/4 " diameter sphere from passing through the openings
anywhere in the gate, and in that portion of the adjacent fence that the gate covers in the open position.
3) All exposed pinch points are eliminated or guarded, and
4) Guarding is supplied for exposed rollers.
b) The operator is intended for installation only on gates used for vehicles. Pedestrians must be supplied with a
separate access opening.
c) The gate must be installed in a location so that enough clearance is supplied between the gate and adjacent
structures then opening and closing to reduce the risk of entrapment.
d) The gate must be properly installed and work freely in both directions prior to the installation of the gate operator.
Do not over-adjust the gate sensitivity to compensate for a damaged gate.
General Information continued...