What is a Z-Wave Contactor and what can it do for me?
Ever want to control a pool pump, hot tub, jacuzzi, well pump, or anything else that takes a considerable amount of power? Well, we get those requests quite often!
What is a Contactor?
A contactor has been around a lot longer then Z-Wave and can be used in many applications, for example car electronics or your refrigerator. A contactor is an electrically controlled switch used for switching an electrical power circuit, similar to a relay, except with higher current ratings. Contactors are controlled by a circuit with a much lower power level then a switched circuit. Contactors come in many forms with varying capacities and features. Due to the large amount of power contactors channel through we STRONGLY (100%) recommend consulting with an electrician... 220v bites!
Here is visual diagram of a typical install
So lets explain this diagram. Start at the electrical breaker and follow to the ELK-9200, this is your 100% hot power line. This hot line from the panel gets wired into contactor. Think of the contactor as a big switch. Then on the other side of the contactor your line goes into the water heater. This allows the water heater to be turned on or off.
Now, where the magic happens is the Automation appliance model! When this device turns power on or off, the contactor switches on or off sequentially.
Many people will ask, "Why can't you just plug the water heater into the Appliance Module"? This is not possible due to the amount of power the water heater requires, it requires much more than a 15amp appliance module or switch can handle.
By using a contactor we can control as big of a power load as desired. Meaning you are able to turn on and off power to Hot Tubs, pools, split AC units and anything else you can think of.
Where do I start?
You will typically want to start by looking at the appliance you want to control. On the appliance there will be a power rating that it consumes. You will always want to make sure your equipment can handle the load. You will want to check that your wire, breaker and contactor are all able to handle the load you plan to wire.
There are a few ready to go Z-Wave Contactor modules available. One is the Elk 9200. This device can handle 110v or 220v up to 30AMPS. You will also need a Z-Wave appliance model as shown in the diagram above. We recommend the Dragon Tech Z-Wave Plug-in Appliance Model (Has Z-Wave Plus Chip)
In this picture we have 3 Elk 9200 plugged into GE/Jasco Z-Wave Receptacles and wired to 3 Split HVAC Systems. This allowed a Vera schedule to cut power to AC units at certain times and ultimately save on power consumption.
Another alternative is the Aeon Labs Heavy Duty Appliance Switch. This device will handle up to 40AMPS at 220V. Another nice feature is the power consumption meeter which allows you to track how much power your appliance is using.
I need something a little different
If these products do not meet your needs you can always build a Z-Wave Contactor. Below is a picture provided by waterheatertimer.org.
In this picture you can see a DPST contactor was used and wired to a GE 45709 light switch. This not only allows you to manually turn on the water heater but also control it with a Z-Wave Hub.
Thanks for reading!