So I have been looking around for z-wave relay options, as I have been planning a lawn irrigation system. I am guessing I will need 4 zones, and there are seemingly no real (affordable) options for valve control through Vera. There is the Fortrezz valves however at over $300 ea that would almost alone blow my sprinkler budget. I would like to simply use relays to control the 24v diaphragm irrigation valves. Looking at my options I saw the nice little pile of extra Jasco modules I picked up from the Radio Shack clearance. Tearing into a appliance module to modify it to be a simple relay I had the chance to learn how to do this, and now I would like to share this with everyone here. I can only assume that quite a few of you have these appliance modules (ZW4101-WCS) from the clearance, and at ~$15 ea they make nice cheap relays.
Disclaimer – These modules are controlled by 120VAC and as such internally this voltage is present on much of the circuit board. This is a very dangerous situation and could potentially cause DEATH. If you don’t know how to safely handle this then please don’t. Also I am not responsible for any hazardous situations created from this mod or damage caused.
Now that that is out of the way, time to get out the soldering iron ;D
After opening the module you should see this. Keep in mind you will need either a snake eyes security driver or a saw.
Pay attention to the hot lead on the right, and the trace coming off of it. This provides the 120VAC to the relay. When the relay is activated it sends that current through the relay and out to the socket. This needs to be undone to allow isolated relay contacts. Also you can desolder and remove all of the wires that go to the two sockets.
First I had removed some solder and cut and removed a portion of the trace from the circuit board. However in testing I found that was insufficient. Underneath the circuit board there was another trace. Reaching this trace would be a pain as I would need to desolder 16 pins to separate the two boards. So out comes my trusty dremel. Using a 1/16 inch carbide bit I CAREFULLY cut through the board to not only sever both traces, but to also provide some separation (insulation) between them to prevent possible arcing in the event of a surge.
Looking at the photo of the end result shows how this can now be used as a isolated contact relay module to control whatever you want. You can also cut the traces between the two sets of contacts on the relay to have two independent contacts SPDT, keeping in mind there may be another trace underneath.
Eventually I would like to install 3-4 of these into a plastic enclosure and wire them all to a terminal strip, with led’s and relocating the momentary control/include buttons. Doing this is a fair bit of work but you can have custom relays to control just about everything.