Spring Balance; Testing; Spring Setting; Correcting Spring Settings - Chamberlain LiftMaster BARS1 Mode D'emploi

8

Spring balance

The spring in the barrier equalizes the weight of the barrier pole. It is essential that the correct
spring is combined with the correct barrier length. If the barrier pole is not balanced the unit does
not work well, the barrier does not close/open completely and the life span is drastically shortened.
8.1

Testing

Release barrier and lift barrier pole manually and let go in the following different positions: 15°,
30°, 45°, 60°. The barrier pole should not move from these positions. It remains in the unhanded
position only held by the spring. If the setting is incorrect readjust spring setting.
8.2

Spring setting

Depending on model used different springs have to be used in order to balance the pole length.
Springs:
Pole length
2.5m 3.5m
3.5m 4.5m
4.5m 5.0m
5.0m 6.0m
6.0m 7.0m
7.0m 8.0m
Additionally there are two drillings situated at the lever of the barrier shaft. These drillings amplify
or reduce the force of the spring. If the pole length is borderline between the indications then use
the drilling further away from the rotation axle. The spring has a longer life span if less tensioned.
Attention: before retrofitting to a different drilling relax spring! The barrier pole, if already mounted,
has to be in the CLOSE position (horizontal).
8.3

Correcting spring settings

With open barrier the spring force can be adjusted through the service door.
It is a right-hand thread setting. Screwing in heightens the spring force.
Screwing out reduces the spring force.
Lever drilling Spring diameter
2 5.5mm
1 5.5mm
2 6.5mm
1 6.5mm
2 7.0mm 2 springs
1 7.0mm 2 springs
1
2
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Notes
1
2