I have a brand new walking treadmill that triggers circuit breakers when the treadmill electronics are powered on but when the treadmill motor is NOT running. The strange thing is that it triggers circuit breakers on circuits it is NOT plugged into.

My office and living room are on separate circuits. I plug the treadmill into a socket in my office and power on the electronics (but not the treadmill motor) and the living room breaker is triggered. Sometimes it happens immediately, sometimes it takes a few minutes, sometimes it doesn't happen for at least 30 minutes (so far at this point even with the motor running with me walking on it).

On one occasion it did trigger the office breaker while plugged into an outlet in the office (but this has only happened once, whereas the living room circuit has triggered instead on about 10 other tests).

UPDATE: Running the motor seems to prevent the circuit breakers from trigering. I walked on the treadmill for about an hour and a half and the breaker only triggered a few minutes after I switched the motor off but left the electronics on.

UPDATE: Pictures of breakers enter image description here enter image description here

  • Are the triggered breakers AFCI, GFCI or ordinary breakers? Commented May 28, 2021 at 18:00
  • When you trip the living room breaker from the office, does the office power stay on?
    – DoxyLover
    Commented May 28, 2021 at 18:06
  • @DoxyLover Yes it does Commented May 28, 2021 at 18:46
  • @manassehkatz-Moving2Codidact they appear to be CAFCI (?) I've added pictures Commented May 28, 2021 at 19:04
  • Which light on the AFCI that trips comes on when it trips? Also, what loads are on the circuit that is tripping when it's tripping? Commented May 28, 2021 at 20:07

1 Answer 1


The electronics of the treadmill are putting out "noise" that the CAFCI breaker is interpreting as a potentially dangerous arc. This can be caused by all kinds of things, including motors, but in this case the motor is fine and it is "no motor" when you have a problem. My hunch is that the noise of the electronics gets "lost" when the full load of the motor is in use but when it is by itself it stands out and the CAFCI treats it as a problem.

A few possible solutions:

  • Check with the treadmill manufacturer. They may have a fix.
  • Put the treadmill on a heavy-duty surge protector. Make sure it is rated to handle the full load of the treadmill. A surge protector is primarily to protect problems in the incoming power from affecting a device, but it can help with problems in the other direction too.
  • Check with Siemens. They may have newer/better CAFCI breakers that you can swap. A newer design may handle the noise more selectively, preventing false positives.
  • Check other breaker suppliers. Carefully. You can't simply "swap breakers from different brands", but there are some situations where one brand will make a breaker that is listed/certified for use with another brand. In other words, it has to be specifically designed to be compatible with your Siemens panel.

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