LiftMaster BG770 Industrial-Duty Single Arm Barrier Gate Operator - Manual (Page 6)

6
PAD MOUNTING
1. Layout the concrete pad (Figure 2). Be sure to locate electrical
conduit inside the hatched 14" x 13" area.
2. Excavate required area for pad and conduit. Pad depth should
be below the frost line or as required by local codes.
3. Pour concrete pad. Concrete pad should be level and above the
ground line.
4. Allow the concrete to set at least two days before installing
operator.
5. Secure operator with four concrete anchors (not provided).
ARM FABRICATION
MODEL BG770 (SINGLE ARM)
If you are making the arm yourself, refer to Figure 3 and its
suggestions for the single arm design.
1. Drill four 1/2" diameter holes using the arm clamp as a
template. Tapering the wood as shown helps reduce the
weight and allows you to reduce any warping common
with long lengths of lumber.
2. Cut to desired length. Refer to Calculate Arm Length below.
3. Finish arm with exterior grade paint and stripe with paint or
adhesive backed tape as required.
MODEL BG790 (WISHBONE ARM)
A 24' wishbone arm is provided as standard with every BG790
gate. If a shorter arm is desired, the extension may be shortened
(Figure 4). The maximum arm extension is 8' for a total arm
length of 24'.
1. Cut to desired length. Refer to Calculate Arm Length below.
2. Finish with an exterior grade paint and stripe with paint or
adhesive backed tape as required.
I N S T A L L A T I O N
Figure 3
Material:
6: x 1" Pine or Redwood
Length as needed
up to 12'
3"
5-12"
Figure 2
12"
14"
20"
14-1/2"
Conduit Entry Area
Arm
13" 22"
Material:
4: x 1" Pine or Redwood
Arm Extension
Length up to 8'
Figure 5
CALCULATE ARM LENGTH
To calculate the arm length:
Subtract the height of the output shaft and concrete pad (40")
from the height to ceiling (see Figure 5).
EXAMPLE:
If height to ceiling is 8'3" (99"), calculation is as follows:
99" (height to ceiling) - 40" (height of the output shaft and
concrete pad) = 59"
Lower arm should be 59".
Figure 4
Height to
ceiling
Arm length Output Shaft
Arm
Height of the
output shaft and
concrete pad (40")