Oddball product issue

[Croy9000]

I wasn’t sure where to post this, but since it’s related to my EcoFlo Power Hub hub figured I would try here.

I have custom built a Sprinter camper van and have a AC mains convection microwave running off of the DC to AC inverter of the Power Hub.

Since it’s a convection oven, I have installed 2 AC mains computer fans to help with ventilation. And in order to automate them turning on and off I bought a cheap automatic switch that detects the current draw from the microwave. It turns the fans on when it detects at least 30W of draw.



It’s all working as expected except for one bizarre issue. Whenever the EcoFlo Power Hub goes into cooling mode, it’s triggering the automatic switch somehow. So essentially when the Power Hub fans kick on, so does the microwave fans I added. as long as the PowerHub  fans are running the switch stays triggered.

Can anyone think of what might be causing this?

[thm_w]

Might be some sort of EMI issue.
Did you try unplugging the microwave when the "cooling mode" is on and verifying the power outlet still stays switched on?

[Croy9000]

Yeah, I did actually. Unplugging the microwave did turn off the automatic switch after its normal delay, while the Power Hub fans continued to run. Which kinda makes it even more bizarre. 

I will say the Power Hub is pretty far away from the microwave and switch (half a vans length).

[thm_w]

If you have a AC power meter, put that in series and see if the microwave is drawing any power during that time.

Filtering might help, or you could probably modify the unit to not trigger until it sees a much higher power draw (say 300W).

[paul8f]

What's the brand and model of the automatic switch?
Do you have any of its specs available?