Gate motor ratings from the manufacturer are based on the maximum weight it can push at the slowest speed using all new hardware on a standard swing gate. Worn hardware increases the load and so does a gate’s infill.
The many factors below increase the effective weight of a gate. When you’re matching a motor to a gate, remember each of these things adds to the load on the motor.
Gates with solid infill panels make the gate act like a sail and can put massive force on the motor.
Absorb water making the gate much heavier.
Rusty or misaligned hinges without lubrication make the motor work hard.
Long gates have more momentum and put more strain on the hinges when compared to a high narrow gate of the same weight.
The faster you push it the more force you’ll need.
Automation using linear drive motors puts a lot of force on the hinges. Welded butt hinges are a disaster waiting to happen. Tapered bearing hinges on the bottom with ball bearing top hinges are the way to go.