What Size Generator Do I Need to Run a Garage Door Opener?
The opener's start is a short spike. Compare it with a small inverter's maximum.
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Running and starting watts
| Load | Running watts | Starting watts | Source |
|---|---|---|---|
| Garage door opener | 720 | 1,420 | Honda |
Honda's wattage guide lists starting watts, then running watts. Champion's chart lists running watts, then starting watts. This table puts every figure in the Running and Starting columns. Not listed means that source does not give a separate starting figure.
How to size it
Add the running watts of every load that will be on together, then add the single highest starting surge (Generac; Honda). Generac notes that starting watts are often 2–3 times running watts, and that standby units should get a dealer survey.
The opener is usually a short run, so the 1,420 W start is the number that matters. If another motor starts at the same moment, keep only the higher start and add the other load's running watts. Generac describes that rule.
Check a full load list on the generator size calculator.
Run the generator outdoors only, 20 ft from the house (CPSC).
FAQ
How many starting watts does a garage door opener use?
Honda lists 1,420 starting watts and 720 running watts.
Can a Honda EU2200i open a garage door?
Yes on this chart. 1,420 W is under the 2,200 W maximum, and 720 W is under the 1,800 W rated output.
Is there a Champion figure for an opener?
Not in the source list used here. The only published row is Honda's 1,420 W start and 720 W run.
What if the opener shares the generator with a compressor?
A 1 hp compressor start is 4,500 W on Honda's chart, far above the opener's 1,420 W. The compressor becomes the highest start.
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