CENTURION Mini Product Catalogue

Monday 5 December 2011

When gate motors collide...

Faultfinding a recalcitrant gate motor can be a frustrating and time consuming process, and it is often unclear exactly what one should be looking for.  Our latest blog post aims to assist the individual user in accurately diagnosing, preventing and rectifying a false collision condition.

So you’ve finally decided you’ve had enough of getting out of your car in torrential downpours, sleet and snow to open your gate, and your medical aid is refusing to pay for another visit to the chiropractor brought on by pushing half a ton of steel up and down.  You’ve had a gate motor installed and you’re already revelling in the wondrous sensation of dry clothing and an unstrained back when suddenly...

Oh no!  You’re trying to close your gate behind you but the thing just moves half a meter, stops and reverses like it’s performing some strange mechanical dance.  It repeats this bizarre jig three or four times before coming to an abrupt halt in the open position, leaving your driveway a gaping maw, unguarded and unsafe.  There is a sinking feeling in your belly as you re-add both the drycleaner and chiropractor to your speed dial.  Your gate motor has encountered the dreaded false collision and it’s the end of life as you know it, or is it?
Fortunately CENTURION is here to help you prevent these frustrating and incapacitating false collisions from occurring and ensure that you enjoy many hassle-free years from your gate motor.

First off, a visit from Captain Obvious.  Right off the bat you need to make sure that your gate motor has been properly installed according to spec and that all relevant site considerations have been taken into account.  These considerations include things like the weight of the gate, the force needed to set the gate in motion, whether the gate is installed on an incline, etc.  A good way to check the pull force – which really is key when selecting a gate operator – is to use a fish scale to pull the gate, then reading the value off and comparing it to the specifications given in the motor’s documentation.  An installer should always leave all relevant documentation such as user’s guides and installation manuals, with the end-user.
Okay, so we’re satisfied that the installation is indeed a good one.  Now what?

Well, now we can start looking at the possible causes of the false collision circuitry activating.  The most arbitrary of things such as stones blown onto the rail, a missing tooth in the rack or an uneven piece of welding, can all cause this condition.  Captain Obvious makes his appearance again and tells us the best way to check for the aforementioned hindrances is to actually open and close the gate by hand a number of times and seeing whether it sticks or jams at any point.  Ensure that the rail is clear of stones and debris, that the rack is not pressing down on the pinion (the toothed gear that moves the gate along its travel), that there are no bad rack joints or missing teeth and that the rail is completely even. 
In addition to this, many gate operators have adjustable sensitivity settings which can be adjusted to a lower level so as not to give false collision readings.  Keep in mind, though, that the collision circuitry is there for a reason and if you have kids or pets it is always advisable to have the operator as sensitive as possible.

Ensuring that your gate has a smooth road to travel on is the first step towards a lifetime of good service from your motor, and may just save you going to the angry chiropractor with hands fashioned from granite!


  1. Hi there, nice post. This is an interesting and very informative topic. Thanks for sharing you thoughts on this issue. Keep it up, looking forward to read another one in the future. Cheers!
    When it comes to fence gate motors, the right product can make the difference between a lifetime of worry-free operation and frequent malfunctions and costly replacements.

    1. Hi Layne. Thank you very much for the compliment. If you haven't already and would like to do so, you can subscribe to the RSS feed or to receive email notifications when new articles are posted, in the top right-hand corner.

  2. Fantastic info for my installation work. Right now I'm dealing with a gate motor which has just got this very problem. I have replaced battery but it keeps giving false collisions and displays motor faulty error masge. It will drive half-way the jeks,jeks and reverses not even to end buts stops somewhere and will not move. Could I suggest it is the above problem.
    Regards Henry Nkandu

    1. Dear Henry. Thank you so much for your comment and for taking the time to read our blog. The problem you describe seems to be indicative of a faulty encoder system (the system responsible for telling the gate motor what the gate's position is). What I would suggest is the following: unscrew the thumbwheel completely so that it is loose in your hands. Next, check for signs of oil on the tip of the threaded stud used to secure the thumbwheel to the gearbox. Oil leaking into the encoder chamber is a common cause of the issue you describe. Also, ensure that all cables and harnesses are securely tightened. If you need some more guidance, please don't hesitate to contact our technical support team on 0861 003 123.