Posted September 18th, 2020 at 6:21 pm by Dan Musick
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. The installer would also change the transformer, so the primary voltage matched the building voltage.
Rather than manufacture one operator for 110 volts and one for 220 volts, LiftMaster designed dual voltage operators. This simplified the process of setting voltages on single-phase LiftMaster operators. By doing this, they were able to cut their warehouse inventory in half for the two voltages. And, for the “oops” events where an installer doesn’t realize the difference until he had installed the unit with the incorrect voltage, the solution is simply a matter of unplugging a wiring harness connector from one socket and plugging it into an adjacent socket.
LiftMaster achieved this design by installing a dual voltage transformer with wiring harnesses running from the logic control board to the power supply. In the image below, either 110 or 220 volts will work.
More information is on our YouTube channel.