Creating a home automation system is great fun but can also cause significant damage to your property and to your health. I am not liable for any direct or indirect damage caused by following these tutorials. Nevertheless most of the tutorials here is absolutely safe to experiment with and ones that pose as a risk are marked with a safety notice.
Always follow safety recommendations and don’t do things that you are unsure about!
Legal disclaimer
Electric shock hazard
It’s the amperage that kills not the voltage… It shouldn’t do any harm if I touch only with one hand… Don’t need to check it, blue wires are always safe to touch… – No, it doesn’t work like that!
If you agree with any of the statements above and/or don’t have qualification to work on 120/230V circuits please don’t do anything that connects directly to the electricity network! There are lots of projects you can try that are operated from a USB port so please play with those!
Fire hazard
This often underestimated hazard can can cause significant damage and can be extremely dangerous to any living creature so please follow the guidelines and commonsense. And of course: don’t do if unsure!
- Electric circuits can get really hot when a high power is dissipated on a segment of the circuit that was not designed to do that. This phenomenon can appear when the resistance of a small part of a circuit unexpectedly increases. Imagine that you are operating a 1000 Watt electric heater. In a 230V power network it means you have ~4.35 Amps (1000/230) running in your circuit. Now a connection loosens up and a certain part of the circuit that used to be 0.01 Ohm is now 10 Ohm. Suddenly you have 37 Watts dissipating on a component that was never designed to that. Remember touching a traditional 40 Watts filament light bulb? That’s the heat that can start the fire in your flat our house.
- When electrical connections like screw terminals and such loosen up the same thing can happen so it is important to properly tighten connections and never try to push more cables into a socket then it was designed to accept!
- Many home automation devices use relays to close or open circuits. Relays’ contact surface wore with time and the resistance increases. When using relays with 120/230V networks always think about what would happen if it caught fire and also check them over time.
- Electric heating elements can get hot. Maybe this is not big news to you but dangers are still there.
- Many of these devices were not designed to be switched on for too long as they can overheat. Your home automation system can fail and accidentally leave certain devices switched on. Always think about what would happen if you could not switch off the remote controlled device for any reason for a long time.
- In a normal household families put stuff on top of different stuff all the time. It is very easy to throw a blanket on an electric heater and normally you would not switch it on like that. But will your home automation system know about the blanket covering the heater?
- Most home improvement stores offer fireproof / fire retardant foams and tiles. These are pretty inexpensive so use them whenever it is possible.
Water flooding hazard
Automated garden watering systems, self irrigating flower pots are fun but what happens if the system doesn’t stop itself. Always make sure that there is a passive, mechanical fail-safe fallback option (like an overflow drain, mechanical pressure valves, etc..) to keep things under control even if your home automation system cannot.
Hazardous gases
Online markets are full of cheap CO2, CO, methane, propane, etc.. sensors with existing arduino and raspberry libraries. Should you get these, make experiments or integrate them into your home automation system? Totally. Should you trust them? Never.
To detect and warn about hazardous gases always use certified detector devices from professional stores. No one guarantees that your 4 dollar MQ9 sensor board from Aliexpress will save your life.
Risk of Theft, Burglary
By implementing a home automation platform you may open unwanted backdoors for people with intent of theft and burglary. Having a stranger switching your lamps in your living room is one thing, having your garage door opened is an other.
Objects that can enable someone enter your property or take something from it should be connected to your home automation platform with extreme caution. If you are not experienced with IT security use an off-the-shelf solution for critical areas and do not connect it to your DIY system.