My basement sump pump works on a simple principle similar to most other sump pumps: A water-level switch turns a 120v receptacle on and off, and the pump plugs into that receptacle. For reference, this is the switch I use (it's the best sump pump switch I've ever used), and that simplex receptacle on the front is what is switched.
I'm looking for something (Z-wave or Zigbee) that I can plug into that simplex receptacle and then plug my pump into (a pass-through) that will monitor when the power is on (pump is running) and when it's off (pump is not running). I've seen several suggestions for plug-in pass-through power monitors, such as this neat little device, but those will not work. They would simply shut off and disconnect from the Hub when the pump was turned off. My imagined solution would need an external source of power so that it would always be on and would simply be monitoring whether the receptacle was on or off. I don't need it to control the pump (in fact, that functionality would be bad, because if it misbehaved, it could disable my pump), and I don't need to monitor current usage (though that wouldn't hurt). Just on/off status.
How about a relay? RIB makes a bunch of different relays. You could get one that would switch dry contacts with 120vac. Connect the dry contacts on the relay to a battery powered Ecolink Z-wave contact sensor (that has screw terminals just for this).
Does that water-level switch also just plug into a regular outlet? If so, have you tried your z-wave power plug at that connection? I have no idea if it would read higher when the pump is running vs not (I think that depends on how the water-level switch manages power), but if you happen to have all those things in-hand now, it may be worth trying?
Or maybe that's all crazy talk -- just trying to exhaust options that don't involving getting new/add'l gear.
The power plug wouldn't be powered when the sump pump is off.
I'm not sure how a z-wave plug would take to having long periods of power off time, mesh wise.
I guess you could plug it into an extension plug.
I think that plug may have an auto on/off feature.
It could turn off after a little while of being powered on, reporting this to the hub,...if it was connected.
What @velvetfoot said. RIB activates when 120V AC detected, activating Zwave or Zigbee dry contact sensor wired to it. I do this with the generator start relay on asolar inverter. There's no generator connected to it, but when the battery gets down to a certain set point that we hit only in winter, it activates the dry contact sensor and I can get a push notification (and it turns on an AC switch to the household grid system, to charge the batteries). The RIB would take on the same role as my gen start relay.
How about a relay? RIB makes a bunch of different relays. You could get one that would switch dry contacts with 120vac. Connect the dry contacts on the relay to a battery powered Ecolink Z-wave contact sensor (that has screw terminals just for this).
What @velvetfoot said. RIB activates when 120V AC detected, activating Zwave or Zigbee dry contact sensor wired to it.
Yeah, I think that's probably my best option. One of these to pass through power to the pump from the controller, cut off the end and wire it into one of these, then wire the relay contacts to something like this.
Upon further consideration, I might forego the Z-wave dry contact sensor. I think I'm already going to be setting up a Raspberry Pi next to the pump with an ultrasonic sensor to monitor tank level. It might make more sense to just wire the dry contacts of the RIB into the GPIO on the RPi. Then all my pump monitoring can happen on the RPi.
*apologies to those that may have suggested same . It wasn't obvious without clicking links.
A power monitoring outlet is a smart choice.
I just did this kind of thing with a sewage ejector which is similar to a sump pump. You have some other choices.
Use a contact sensor of your choice wired to a dry contact sensor like the below. These sensors are not powered so you can safely use them. What I have done in the past is wire them with a short extension cord. You can then move it around to whatever you need to sense.
I use a liberty float alarm that has a dry contact. I wired this up in a way that I can alert with a zigbee contact sensor and a flo sensor toshut off my water using a Flo.
The way these work is you only put the load wire through them. So, yes, it would work with two legs because you would just need to put one leg through it.
