Hi all, I'm about to have a boat lift installed which will use a 240v 50A circuit and 8ga wire due to the distance. It will be sourced from a location that is not particularly easy to get to (12' off the ground) due to flood zone elevation requirements. For security, I'd like to be able to cut power to the lift when not taking the boat out. Was curious if anyone's built out a z-wave/zigbee-based solution using a relay that would allow for switching this type of load? Then I could simply flip the circuit on via Hubitat.
I found this thread Larger Load Control - #13 by LosinIt where LosinIt seems to have exactly what I'm talking about; he's got a regular 120v z-wave outlet doing on/off duties for a high-amperage relay feeding a large motor. Unfortunately the relay box had come with his dust collector so there's no detail on what make/model that box is so I could see if there's something similar I could wire into my circuit. I can easily wire a 120v outlet next to this circuit to hold a smart outlet if that ends up being what controls the relay, just haven't been able to find the right relay search terms.
I've done this with one of these. I used an Inovelli switch as the trigger but it could be any switch. This relay uses 120v to keep the relay active though so it hums while it's active. There are low voltage trigger models available but I haven't seen one of those already mounted in a protective housing.
Correct, but there is nothing special about it. It's a standard steel electrical box large enough to contain the relay and leave room to easily wire it up. It's about 7x7" and 6" deep. You can get them at an electrical supply or hardware store like HomeDepot or Lowe's. I suggest you get a relay rated for at least 10% over the expected current (remember that motor starting amps can be much higher than the commonly cited running amps) at 240VAC and has a 120VAC activation coil and then size the box accordingly.
A separate circuit is not needed as you can get the 120 from either side of the 240 supply and the neutral wire. I am NOT a certified electrician so you should verify what I've said is according to code where you live by having a chat with a qualified sparky.
Thanks; yep I'm comfortable doing the wiring. I just meant I could easily place the 110v outlet next to the breaker box the lift circuit will be served from, and then run that wiring through the appropriate relay. Do you know which relay your equipment uses as it sounds like it likely has similar current carrying requirements?
There are a couple of Z-Wave devices available that are rated at 240, 40 Amp. Unless you truly need 50 amps either of these might be worth considering.
Looks like the one @Terk posted should work great. I spoke to the lift installer and he said my lift motors only require a 50A breaker because of the start-up demand, but full load draw while lifting the boat will only be about 8A per motor, so 16A in my case. That iVac contactor he posted is rated for 40A continuous with 150A start, and seems like a fairly rugged device.
