I was wondering if anyone has successfully used a z-wave device inside a grounded metal utility box. This is for an outside outlet switch used to control an electric water pump for a waterfall in my pond. There will also be an Ecolink door sensor hardwired to a water level sensor switch and powered by a 3.3-volt adapter (no battery). The Ecolink sensor does have a little wire antenna inside it which is easy to access. I was thinking about possibly running a wire from the antenna to the outside of the metal box. The nearest z-wave device is about 20 feet from the pond switch.
I have been using PVC boxes, which work great but have a tendency to crack after a couple of seasons in the hot sun and snow, so I need to replace it with something more durable.
All my Z-Wave devices are in metal wall boxes with the grounded aluminum dimmer front plates. Not the same but may give you hope.
If it doesn't just work I would try a piece of insulated (relatively straight) wire sticking through your box wall (RTV) about the same length inside and outside as the wire antenna of your Ecolink. I would first try with no connections to this wire.
It reallay depends on the construction of the metal electrical box. I have seen some boxes that are well enclosed such that the box will act as a Faraday cage and block all RF emissions. However, I also have Zigbee temperature sensors inside freezers that are essentially metal boxes, but they have a plastic seal which apparently lets the RF through. The sensors work.
Remember that RF waves will bounce around inside the metal box looking for a way to escape. In a metal outlet box there are places the signal can get out. However, I would not recommend using a metal cover plate on such a box.
You might find that removing a metal knockout plug on the side or bottom of the box and covering it with a plastic might be sufficient to all the z-wave signal to escape.
Remember that Z-wave signals have a longer wavelength that Zigbee signals. If the Z-wave sensor does not work, you might have better success with a Zigbee sensor. The shorter waves do not need as big an opening to escape.
