The driveway gate pull and running forces should be measured before purchasing or installing any gate opener. Should the measured forces exceed those in the table above for the Ultima units, then the motor must not be installed. It may be possible to reduce these forces by carrying out maintenance on the gate rail but if not, then the motor must not be installed.

These forces can be measured using a fishing or luggage scale (see figure above).

Pull Force: place the gate in the fully open/closed position and pull on the scale until the gate starts moving. The value showing on the scale at the point that the gate starts moving is the Pull Force kgf. This should be checked in both directions.

Running Force: this is the maximum value read while the gate is moving before coming to the fully open position.

Gradient = A (0.3m) / B (4m)

Effective Gate Weight
When is a 200kg gate really 800kgs - Working out the effective gate weight

Effective Gate Weight = 40 x gradient + 1 x actual gate weight
Eg. A driveway, that falls 300mm over 4m (.300/4 = .075 gradient) has an effective weight of 800kgs
Effective Gate Weight = 40 x .075 + 1 x 200
Therefore, the example above wouldn't suit either of these motors

Other Examples:

80kg actual gate weight - Fall 100mm over 4m = 160kg effective gate weight

80kg actual gate weight - Fall 200mm over 5m = 208kg effective gate weight

150kg actual gate weight - Fall 350mm over 6m = 266kg effective gate weight