Zooz ZEN15 Power Switch Showing mW of Power but Zero Amps

I have a zen-15 powering a sump pump. I created two routines to send text messages when the pump turns on and off. Basically, if power >= 0.01W then send text. Simple but something odd happens. I get “running” messages when the pump is not running. I observed the power reading was 35mW for a few seconds, but the amperage was zero. I listened while this happens and the pump is not running. This is like some leakage current getting through the level switch on the pump. But that should be continuous, not turning on and off at regular intervals. Perhaps the zen-15 is feeding a low current periodically for some test or analysis purposes? Does anyone have any clues about this?

I am assuming your sump pump draws much more than 0.01 watts so increase your threshold to a more reasonable number. You could even add a short time (1 or 2 sec.) delay in your automation.

I have my sump pump automations set to trigger at 50 watts, for a pump that draws 800 watts when running.

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Thanks. I had it at a higher number before, and that fixes the run detection. Now, I’m getting lots of stop messages without starts. Must be the 35 mW signal turning off. Using if(power <= 0) then send text . When do these tests execute? continuously every x seconds? Power update frequency? When the power changes?

In the IF part of your Stop automation try putting a 1 to 2 sec. delay and see if that helps.

As @Paul_Oliver suggested, the higher threshold is reasonable for detecting the ‘run’ state.

if(Power >= 50) then send text

You might also try a higher threshold for detecting the ‘stopped’ state. Say,

if(Power <= 49) then send text

You’re really just looking for a binary state of ‘on’’ or ‘off,’ not how much power or current is drawn by the sump pump.

Question: Is the circuit powering the sump pump by any chance on a ground-fault outlet or ground-fault circuit breaker? The “leakage” current, if that’s what it is, would probably trip the ground fault–if it’s real and not just an artifact of the switch’s metering circuitry!

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Good point. It’s an outside receptacle, so I’m assuming it’s on a GFI. So, the phantom currents are probably an artifact of the measurement method. Switching to amperage rather than power, and adjusting the run limit, totally stabilized both routines. I don’t think time delays would help now. *** is there a way to embed date, time or values in a text message?

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