- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
I’m curious to know the brand of dishwasher. I just had a new LG unit installed last year, and everything was fine. Then 5 months ago I had solar installed with a battery system. In the morning when the battery starts to recharge, my dishwasher will sometimes chime as if it was powered up. At first I thought I was hearing things, but I was right there in the kitchen once and saw it happen. It powers up, then sits there waiting for a Run command and eventually powers down again when it doesn’t get one.
My theory is that the charger has its own internal solid state power switch, so that when not being used it is not consuming power to the internal transformer. So when it is called for, the switch turns on and there is inrush current when that internal transformer is magnetizing. That inrush then causes a ringing transient that makes the solid state power switch on the dishwasher turn off and back on. That can happen easily if they are using a triac or SCR as the main power switch in the dishwasher. In my case it doesn’t happen all of the time (or nobody is home to hear it when it does), which would be consistent with it being an inrush issue, because if the sun is already out before the batteries are separated, it will charge from the solar and I think the solar inverter is suppressing the inrush, but if the batteries are depleted first, it will start charging from the utility and that’s when we see the inrush.
I’m wondering if the Tesla charger has that same power switch so that when not being used, it powers down the transformer to avoid the losses. Then when it is turned in, it creates a ringing transient that the power switch in the dishwasher is reacting to. If so, you would not be able to see the transient without a scope, it’s way too fast for a meter to capture.
My theory is that the charger has its own internal solid state power switch, so that when not being used it is not consuming power to the internal transformer. So when it is called for, the switch turns on and there is inrush current when that internal transformer is magnetizing. That inrush then causes a ringing transient that makes the solid state power switch on the dishwasher turn off and back on. That can happen easily if they are using a triac or SCR as the main power switch in the dishwasher. In my case it doesn’t happen all of the time (or nobody is home to hear it when it does), which would be consistent with it being an inrush issue, because if the sun is already out before the batteries are separated, it will charge from the solar and I think the solar inverter is suppressing the inrush, but if the batteries are depleted first, it will start charging from the utility and that’s when we see the inrush.
I’m wondering if the Tesla charger has that same power switch so that when not being used, it powers down the transformer to avoid the losses. Then when it is turned in, it creates a ringing transient that the power switch in the dishwasher is reacting to. If so, you would not be able to see the transient without a scope, it’s way too fast for a meter to capture.