Need help , noob...

Other Devices & Integrations Climate Control & Temperature Sensors
#1

Hi everyone , brand spanking new to Z-Wave. Have not bought anything yet.

I live in South Africa and our line voltage is 220-240V , frequency 868mhz.

I need a simple unit to control my underfloor heating(220V). All I need is to be able to switch it on/off remotely.

What is the cheapest/easiest option for me? Can I use a regular thermostat with a z-wave switch? Any specifics I need to look for?

I will be using the Vera system(VeraLite).

#2

There are other questions to be addressed.

Do you have an existing thermostat for the floor heater ? Is it line voltage …or does it have a low voltage control circuit ?

The reason to ask is that most Z-Wave devices to not have the load capacity for controlling heaters directly.
If you have a contactor (high current relay) … You can control the contactor with a Z-Wave switch.

If it’s a 24V coil contactor … you can control this with a Z-Wave thermostat (The Thermostat controls the contactor directly … you control the thermostat remotely through Z-Wave. You can also control the contactor with a Z-Wave relay module. Then it behaves as the following scenario.

If it’s a line voltage coil on the contactor … you can control this with a Z-Wave switch. You could add a Z-Wave temperature sensor … and monitor the temperature with Vera … and have it remotely control the Z-Wave switch.

#3

Thanks so much for the response. I haven’t even installed the system yet. It’s for my new house.

Going to be using Electric underfloor heating cable(Dual Core).

The cable is rated at 1800watts. I was thinking of using a simple Thermostat (line voltage) , and running my main power feed via a Z-Wave switch into the thermostat. I think the thermostats come with a floor sensor.

Would adding a Z-Wave temperature sensor allow me to do anything different?

All I need to do is turn the UFH on when driving home on cold days and make sure it doesn’t exceed a certain temperature(I thought the thermostat probe would achieve this).

One more question , would my Z-Wave switch have to be able to support 1800watts? Or would it have to support whatever watts my thermostat require?

#4

Depends on if the “Control” circuit is independent of the the “Load” circuit.

Chances are a “Line” voltage thermostat is just controlling the “Load” directly. In that case the Z-Wave switch needs to handle the full 1800 Watts … that’s around 10A. There are some Z-Wave appliance modules that can handle that load. I am not sure about compatibility with your frequency.

#5

Thanks for the reply.

This is the info I got from the website :

Types Table:
Types Load Current Methods of Temperature Measurement
M5.16 16A Inside Sensor
M5.16D 16A Outside&Inside Sensor

Technique Parameters:
Voltage: 220VAC
Power consumption: 5VA
Temperature control range: 5~40?C
Temperature limit range: 25~55?C
Power save mode temperature: 5?C
Temperature deviation: ?0.5K
Ambient temperature: -5~50?C
Degree of protection provided by enclosure: IP20

Outer sensor: length of cable 3m

I’m not sure if power consumption is the same as the control circuit voltage.

#6

The 5VA is probably how much it draws when it is not powering the heater.
Post the Product URL

#7

This is the url of the simple thermostat I plan on using :

http://www.aliexpress.com/item/16A-heating-thermostat-room-thermostat-temperature-controller-manual-thermostat/698817189.html

And this is the switch I plan to use it with :

http://www.uk-automation.co.uk/products/Z-Wave-Switch-by-Duwi.html

Would it work? Is it the best/cheapest option?

Difficult to find systems compatible with 240v 868mhz.

#8

This combination will work … You would connect the Z-Wave switch to the power … then the output of the Z-Wave Switch to the Thermostat … then the output of the Thermostat to your floor heaters.

Both the Z-Wave switch AND the thermostat have to be ON and the thermostat has to indicate the need for heat for the floor to actually heat.

You could also skip the Thermostat you provided a link for … Wire your heater to the output of the Z-Wave switch. You can add a Z-Wave temperature Sensor … And have Vera monitor the temperature …
If it’s above/below some pre-defined value it could turn the Z-Wave switch on and off.

#9

That sounds like a great idea!!! Thanks so much for all your help.