In most commercial operators sold in the last century, there were two voltages: the incoming line voltage, and the lower secondary voltage from the transformer. This was usually 24-28 volts with alternating current. On rainy days in my early years, this lower voltage would often produce a noticeable shock.…
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Installers and salesmen order sectional door operators to match the operator voltages to the voltages in the buildings. Sometimes salesmen order operators with the wrong voltage, and the operator voltage needs to be changed. This is done by changing the wires at the motor as long as the building voltage was 110 or 220 volts.…
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When I first got into the door business, the most common wiring for a 110-volt circuit consisted of a four-wire motor and two power leads. The two power leads ran straight to the motor. The other wires from the motor could go to either power lead.…
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In order to test the cycle life of different spring systems, we designed a Counter & Timer Modification for LiftMaster Operators. This modification allows the operator to close immediately after opening and to open immediately after closing. This, in turn, allows the operator to run nonstop for days at a time so that a 10,000 cycle test can be completed in just a few days.…
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Garage door opener limit switches electrically limit the door travel as it opens and closes. These switches “tell” the opener or operator when to stop.
The most common limit switch comes in most of the Sears, Chamberlain and Liftmaster openers made since the early nineties.…
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Commercial door operator manufacturers have designed three standard safety systems.
First is the mechanical clutch that slips when the door is obstructed.
The second design is the eye sensor system.…
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In the garage door industry, we distinguish between “openers” for residential applications and “operators” for commercial and industrial applications.
Back in the early eighties, I worked for Northwest Door in Elgin, Illinois. While there, I got to know a gentleman who had formerly worked for John Greene Corporation in Downers Grove, Illinois.…
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Since 1980 I have been training professionals to repair the various types of equipment in the garage door industry. I had started my career with Overhead Door of Elk Grove in January of 1979. The following year, I began training the servicemen there in what was, during that time, the largest garage door sales, installation, and service companies in the industry.…
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Last Monday, employees in both of the DDM companies met to strategize and make changes regarding the COVID-19 Coronavirus.
I began the meeting reading from Psalm 91, and we began with prayer. Here are some selected portions of my text.
We are entering uncharted waters.…
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This week one of our wholesale customers called me about stripped operator drive sprockets. This is usually caused by overstress. However, in this case, it could possibly be due to half-baked torsion springs. I recommend the service tech disconnect the drive chain and check the door balance as per the instructions we have on our “Balanced Garage Door” blog.…
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Huge inventory of parts and torsion springs for same or next day shipping! Here you will find all you need in the most common sizes of 1 3/4," 2," 2 1/4," and 2 5/8" inside diameter springs. Please contact us for specialty springs such as TorqueMaster, EZ Set, self-Storage, and steel rolling door springs as many of these have been subject to supply chain shortages. Larger 3 3/4" and 6" inside diameter commercial and industrial springs may require a day or two to ship.
COVID update. No mask, no service! When picking up parts please wear a mask. We'll gladly provide one. Please honor the six foot social distancing rule. Thank you for your patience and understanding.
Shipping times and costs have changed. Normal transit times are currently not guaranteed, even on next day and second day shipments. Shipping prices on items over eight feet have more than tripled.
