Motor current monitoring

When developing the petWALK pet door, we were aware of our responsibility and therefore installed several independent safety systems.

Motion monitoring

  • Using two very sensitive motion sensors (in the door frame above the door leaf and on the underside of the door leaf), the petWALK pet door detects living creatures and only closes if no movement is detected within a defined period of time (see manual chapter “10.2.2 SETTING THE DOOR OPENING TIME, page 51).
  • If the animal remains motionless in the doorway, it may happen that the door begins to close anyway because the sensors can no longer detect any movement. This is the same effect that you know from elevators or automatic department store doors when you stand in the doorway or briefly enter the doorway while it is closing. But this is not a problem at all because in this not uncommon case, the next safety measure, namely the Motor current monitoring comes into force.
  • You can check this yourself by moving your hand within the swing range of the door leaf when the door leaf is open. Either the exit control or entry control symbol should flash orange repeatedly and the door leaf should not close. However, as soon as you hold your hand still for the set period of time so that no symbol lights up, the door will try to close.

Electronic anti-pinch protection (motor current monitoring)

  • Even the slightest resistance when closing or opening the door causes the door to stop immediately and move slightly in the opposite direction. After a while, the petWALK pet door tries to close the door again with a little more pressure, but still carefully, after a warning tone. After several unsuccessful attempts, the door goes into alarm mode to indicate a problem. A fallen object could be blocking the door.
  • You can easily check this behavior yourself by keeping your hand still in the swing area so that the door leaf hits it. You don't have to worry because in the event of an electronic malfunction there is also another mechanical safety device, described below. After four attempts the door should report the error message "E02" on the display.
  • If the door leaf does not stop immediately and moves in the opposite direction when you try, but instead exerts a very light, continuous pressure and only reports the error message "E03" after a few seconds, then the mechanical safety device is set too lightly. You can correct this yourself with the help of the manual.

Mechanical anti-pinch protection (slip clutch)

  • The drive motor is connected to the door leaf via a mechanical clutch, which automatically interrupts the power transmission when a set resistance is reached.
  • This resistance is chosen in such a way that even if all electronic safety functions fail, the door cannot under any circumstances cause serious injuries, such as a broken bone.
  • Due to the design, the set force can decrease over time and due to wear of the clutch linings and, in the worst case, lead to the electronic anti-pinch protection no longer being used because the door leaf is stopped by the slip clutch even earlier at a lower force.
  • You can easily test this mechanism yourself by opening and closing the door with your hand. This should be possible without much effort. The force you need to apply is also the maximum force that can theoretically act on a trapped object.

Constructive anti-pinch protection

  • In order to be able to move the door leaf as gently as possible and still lock the door firmly, we chose the expensive and complex route and installed two separate drives.
  • The door drive only receives as much power as it absolutely needs for movement and the locking motor can only be activated when an electrical contact is closed and the gap on the side facing away from the axis is less than 8mm.
  • This is ensured by a small wedge on the top of the door leaf and a bolt on the locking mechanism. The bolt can only close the door leaf if the gap on the side facing away from the axis is within the safe range, otherwise it blocks the door leaf from closing.

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