Important factors when deciding on a driveway gate and motor
After a driveway gate and automation but not sure where to start.
First thing first!
Deciding whether you would be best suited for a sliding gate or swinging gate setup.
For a sliding gate, the opening size of your driveway will also require that same measurement for the gate to slide back of your driveway eg, 4mtr driveway opening requires at least another 4.5mtrs of clearance for your gate to slide open. This can sometimes be difficult due to the fall of the land, not enough room or garden beds/other obstructions.
Swinging gates will require you to have enough room for the gate to swing inwards or outwards as either single gates or double gates. Gate length will also need to be taken into consideration when looking at automating your gate as all motors will have a length restriction. This restriction may then lead you from a single gate setup to a double gate setup.
Gate size and design
The size of your opening and gate design may also direct your towards a sliding gate as the better option. If your purpose for a driveway gate is privacy and your gate design is aimed towards something more enclosed to stop people from seeing in to your property, then you would be better looking at a sliding gate, especially if you are automating it. Having a gate with a more solid surface area will create a large wind barrier, therefore with swing gates they will act like big wind sales and could play havoc with your gate automation.
Due to restrictions on gate lengths when it comes to swing gate automation, you may be directed to a sliding gate. Generally customers with a 4mtr opening or larger will lean towards a sliding gate option.
Gate Ground Work
Ground work involved for setting up to install a sliding gate are:
- Posts - a post is required each side of the driveway which your gate would sit behind.
- Concrete Plinth - you will require a concrete plinth across your driveway plus where your gate slides open to. This is where your sliding gate track needs to bolt down to.
- Level Plinth - when sorting out your plinth area, you will need to make sure that the driveway is nice and level, on the same plane all the way. Then where the gate slides back open needs to remain on that same level or plane as the driveway.
- Motor Pad - an area for your motor to bolt down to which is usually a concrete pad.
Ground work involved for setting up to install a swinging gate are:
- Posts - a post is required each side of the driveway. If a single gate then the gate will hinge from one post and if double gates then they will hinge off each post. Due to the weight of the gates and any force applied from added automation, it’s best to have your posts concreted into the ground at least 600mm.
- Ground clearance - it is important to make sure that your gate will swing freely and not hit or drag along the ground.
When it comes to selecting your automation for a sliding there are few factors to take into consideration:
- Length of gate - gate openers have a max run time, therefore if your gate is too long for the motor selected then you will end up with issues of your gate not fully opening.
- Gate weight - all slide gate motors will specify a gate weight. This is important to note, but more importantly is the running force and pull force of the motor. You will see in the explanations and examples below how these figures can drastically change.
- Gradient or fall over driveway - this is a big factor, especially if you have a heavy gate on a large fall. As you can see from the examples below, even a light weight gate can double its actual weight depending on its fall.
- Speed - If you require your gate to open fast (you may be coming off a main road) or you have a long gate and don’t want to wait the 30 seconds that some motors take, then you would be better off looking at your sliding gate motors.
Checking Pull Force & Running Force
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.
Checking the Effective Gate weight if on a Gradient
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 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
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
Swing gate automation also comes with its factors and gate requirements:
- Length of gate - all swing motors will have a maximum gate length requirement. This is due to the leverage required of the actuator arm trying to pull your gate length open. The longer the gate, the more strain placed on the actuator arm to pull and push the gate open and closed.
- Gate weight - swing motors will also have a maximum gate weight they will work off also using the same explanation as the above gate length. You may find that the longer the gate becomes, the maximum gate weight allowed will drop.
- Gate design - this is very important for the functioning of the actual motors. Having a gate design that is wind friendly will prevent your gate from acting like a big wind sail, which in turn places extra pressure not only on the swing motor but also on all working parts of the gate.
Now that you have all of the important factors to help you choose the type of gate that will best suit your setup, we can now look at your power options available for gate automation.
Electric kits come in a 240volt or Low voltage option.
Electric 240V motors are generally a cheaper option to buy but you do need 240V mains power at your gate which can be expensive to install, whereas a 12V or 24V motor is more expensive but can have a low voltage transformer or solar which is generally cheaper in the end. Plugging a transformer into a power point away from the gate then installing low voltage cable out to the gate can be a lot more economic to install than a power point at the gate.
Another advantage of running a low voltage system is they tend to run cooler than 240V which makes it more suitable when a gate gets a lot of use. These units also tend to be more compact in size, run faster because their speed can be controlled more effectively and have the option of battery backup.
Solar powered automatic gates have the advantages of: costing nothing to run, more affordable in most cases to install then power cabling, are environmentally friendly and if the mains power goes out the gate will still work.
The motor doesn't run directly off the Solar Panel, it actually runs off a battery that is kept charged by the solar panel. This way the gate will still work at night. The charging of the battery is via a solar charge controller unit that is normally part of the control box although can also be separate and makes sure the battery isn't overcharged or discharged necessarily.
Solar panels may be installed away from the gate where there is plenty of sun and a low voltage cable run back to the gate. This cable can be light duty as it is only for a trickle charge from the solar panel.
If you have no sunny spot anywhere near your gate, you’ll either have to install much larger solar panels, bigger battery, or run low voltage cable over some distance to where ever a 240v power point connection is available or where there is a sunny spot. The longer the cable the thicker it needs to be to minimise voltage drop.
When adding other devices to a solar gate motor, careful consideration of how much power they use is important. If this isn’t factored in you run the risk of the battery running flat and the gate will stop working.
If the battery of a solar system or any system that runs off a battery starts to get a little low the gate will run much slower than normal and may stop short or half way through its travel. Worst case, if you come home and go to open the gate but it only opens a little bit because the battery has run flat then at least you will still be able to walk in and manually release the gate if you have no other way of getting in.
One thing with solar powered automatic gates is if the battery does run flat it must be charged before the motor will work, the motor cannot run directly off the solar panel, although all automatic gates have a manual release of some sort from inside the property, so having a pedestrian side gate to gain access to the property is a good idea. Also batteries do have a limited life span of 3 years. A replacement battery isn't expensive and are available at most automotive, battery, alarm and electronic shops and if you are able to remove the lid of the motor, unplug the battery and plug a new one in then you can do it yourself and don't need to pay a technician to do this for you.