Mr Spock
Active Member
Tonight I did laundry and whipped out the Kill-a-watt to see what the current consumption my laundry machine uses. I have the Whirlpool Duet front loading model.
Turns out the unit is drawing 0.04A even when it's totally off. Seems like a lot. Unplugging the machine I see it goes down to zero, so its not just offset inaccuracy. But I know the kill-a-watt is not the most accurate at low currents so that might be part of it.
When i turn the cycle on I see the current varies from 6A to 0.14A. It actually spends a lot of time with the motor off during the auto soak cycle at 0.14A (up to 15 seconds) and when its filling with water (up to 2 minutes).
So if I use the model of Functional Devices that trips at the lowest current (RIBXGF = 0.35A) I would need 3 or 4 turns through the CT. I don't know how much hysteresis these things have, so I may need to experiment a bit.
YMMV.
Turns out the unit is drawing 0.04A even when it's totally off. Seems like a lot. Unplugging the machine I see it goes down to zero, so its not just offset inaccuracy. But I know the kill-a-watt is not the most accurate at low currents so that might be part of it.
When i turn the cycle on I see the current varies from 6A to 0.14A. It actually spends a lot of time with the motor off during the auto soak cycle at 0.14A (up to 15 seconds) and when its filling with water (up to 2 minutes).
So if I use the model of Functional Devices that trips at the lowest current (RIBXGF = 0.35A) I would need 3 or 4 turns through the CT. I don't know how much hysteresis these things have, so I may need to experiment a bit.
YMMV.
