Several USA garage door operator manufactures have begun to include the statement “When the door contacts the board, it should stop and reverse direction within 2 seconds to the fully OPEN position” . The amount of force that may be exerted is not specified by UL nor CPC § 1211.7 Inherent entrapment protection requirements, only that the door reverse within 2 seconds of contact with a solid object on the floor for doors without an edge sensor.

Threads and posts on this topic have raised questions about the amount of force that may be found on contact that causes the reversal. We have also discussed methods that are accepted by manufactures on determining the amount of force being exerted by the operator prior to causing reversal and how that force may be adjusted. Looking outside the box I went offshore to see how other countries may be addressing the Force and Reversal issues.

Garage Door Anti-Entrapment Force outside USA

I have found door operators in Australia / New Zealand have in their instructions reference the amount of force exerted and time to reverse on contact.

Some manufactures of door operators in New Zeland are:
Chamberlain – Guardian - Merllin, these may be a re-branding of operators found in the USA.

The following is not an exhaustive research yet interesting when compared to the USA CPSC regulations/specifications. I have not found a source for government regulations/specifications for Australia/New Zealand door operators or I would have listed a link, sorry.

Pg. 18 Testing The Safety Reverse System
2. Place 2x4 on floor
4. The door Must Reverse upon striking the object within 1.5 seconds, and stop at the fully open position.
Pg. 17 “solid object 50mm thick” ….. “door will reverse 1 ½ seconds of contacting object…”

Chamberlain 1140 Garage Door Opener User Manual / Controll-A-Door-P
((Chamberlain which may have been rebranded Controll-A-Door-P in New Zealand))
Found with: B&D Doors, New Zealand: 70 Allens Road, EastTamaki, Auckland, New Zealand(09) 273

(go to PDF link)
Adjust the Force
The force, as measured on the closing edge of the door, should not exceed 400N (40kg). If theclosing force is measured to more than 400N, aSafety Infrared Reversing Sensor must beinstalled See step 3 on page 27.

Now for the math to put the above into perspective. ( I have rounded up the numbers)
Pounds Force – Newtons - Kilograms

1 newton = 0.23 pound-force.
1 pound-force = 4.45 newton
1 Kilogram = 2.21 Pounds

400 N = 89.92 LB

40kg = 392.23 N

40kg= 88lb 2.96 oz

Cobbling things together, the 400 N or 90 LB may be the maximum amount of force that is exerted during the 1.5 seconds of contact, though I have not found the source for specifications. Maybe someone else can turn it up. Also I do not know what devise is being used to assess the force in the field.

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