I am installing electric openers on two new (sectional) garage doors. The doors are top-of-the-line models from Overhead Door, dealer installed. I have always understood that the weight of the garage doors must be counter balanced by the springs. Makes sense.
These doors have a top panel with insulated glass. While the top panel is significantly heavier than all the others, it is also the weakest; therefore, as shown in the instructions, a metal reinforcement plate is added for attaching the opener and a continuous angle iron stiffener is added completely across the top of the panel to prevent the panel from flexing.
Trouble is, how can one get such a door properly balanced? When the recommended tension springs are installed and adjusted such that the door stays down and can be lifted without much effort, the door takes off and must be held back as the top panel moves out of the vertical track onto the overhead (horizontal) track section! Makes sense, since the spring has a constant force rate whereas the door does not.
I see potential safety problems with this situation regardless of whether the door is operated manually or with an electric opener (load sensitivity, reversing and such).
In an ideal situation balance would mean "throughout the entire range"; in the example given in the instruction booklet, balance is check at the halfway point. I suppose I could add weight to the bottom of the door and go with heavier springs to obtain balance throughout the range, but when am I close enough?
If the door balances at the half-way point but it takes X pounds lift it from the closed position and Y pounds to pull it down, what are safe/acceptable values for X and Y with the electric door opener?
Is there an engineer at Chamberlain that is willing to go on record here? - Thanks!