This will be a hard one to find out. I have a central vacuum Drain Vac 2G20028-c , 12.5 amp at 120 volts.
It has a mini 15 amp breaker on the unit. The power going to the vacuum is on a normal square D breaker 20 amp breaker.
After a few weeks of being installed, every time I start the unit for the first time in the day, after about 30 to 90 seconds the 20 amp breaker in the panel trips (not the vacuum 15 amps). Then after resetting the breaker, I could vacuum all day long without any more trouble. The problem is still there (every time I use it !) after having done those thing :
Change the panel breaker for a news 20 amps
Change the 20 amps, 120v power outlet
Having check by the repair shop the vacuum, apparently all is fine
Change the entire cable between the power outlet and the main panel 20 amp breaker
Change the location and again the breaker in the main panel
Except changing the brand of my vacuum, I can't think of anything else. Could electric charge be a problem ? Could moisture be a problem ?
My vacuum outlet is pipe outside with a weather protection flap outlet, similar to those for laundry dryer.