Hi folks,
Does anyone know how many Watts switches like the Zooz Zen71 consume? I can find plenty of information on what kind of loads it supports, the z-wave specs, etc, but I can't find how many Watts the device itself consumes. With lots of these spread around the house and connected 24/7, I imagine the aggregate wattage is measurable.
I'm guessing somewhere in the 500 mW range, but does anyone have any ideas?
-alk
Don't know about the Zooz Zen71, but my zigbee smart outlets consume about 0.5Wh when they're plugged in.
Standby current for zen71 measured as 2.1mA. At 120V this is about 0.25W.
The zwave plus long range (zwlr) Zooz zen71 is being used to replace another vendors original zwave (7 year old) switch.
That switch measured about 2W for standby power.
For this installation, each switch replaced saves over 15kWh per year for about an 87% reduction.
There are more than 30 in this installation.
Two zen71s on the left (white indicators) at 0.25W each.
One of the units to be replaced on the right (green indicator) at 2W.
Since these are all in the same box, zen 71 temperatures likely appear higher due to heating from the neighboring switch.
A dimmer switch has losses when it is on due to the triac VI power loss. That is normal with any dimmer switch. So an i/r heat map with the switch on isn't necessarily a problem.
Quiescent losses due to the Zwave and micro-controller power consumption are legitimate concerns but at 1/2W (as other suggest) that is $0.60 of power used per year per switch. So if you have, say, 20 zooz switches then they cost you $12.26 per year. Seems a small price to pay for the value you get in return. I suspect Hubitat draws 10-20x that
The zen71s are being used as scene controllers and have no loads attached. They are configured with their output relays disabled.
The switch they are replacing is just a zwave transmitter product containg no output stage. It is essentially a scene controller as well albeit a much simpler one with a far less capable radio.
I was trying to be kind to the vendor I am replacing by realized that I posted on this projeçt elseware so the name is out there.
They are nutone NWT00Z which is a zwave tranceiver with no output stage.
On a tangential remark, I have a bunch of ZEN73 toggle switches now and am looking at making the led more visible. I like the led's on your ZEN71's!
C8 pro measures about 2.2W typical in standard operation. This is serving only zwlr, zigbee with wifi backhaul to hub mesh.
Good job hubitat team!
Data follows...
18.5mA after boot in stable operation.
22.2mA peak current in normal operation.
32.4mA peak in boot up.
0.2mA usb power cube, no hub attached.
I really appreciate the careful power design right down to the selection of an effecient usb cube.
Quite a feature and worth touting.
@kent1 Excellent! Thanks for pulling out the clamps to look into this. A 10x reduction in power is a considerable savings - indeed, measurable.
-alk
My bottom line is that power is always important and its more than just a cost issue.
One way or another, power burn turns into heat and heat is what exponentially ages electronics.
Semiconductors are based on diffusions which move over time depending on thermal inputs. Filter capacitors leak at rates related to the same physics. Both can be discribed using the Arrhenius equation.
Basically product lifetimes approximately halve for every 10C (18f) in temperature increase.
So Hubitat and Zooz are giving us a much more reliable product by sweating the detail of power engineering.
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