Question regarding certification / legals - connecting to mains power

Hi there, something just occurred to me... if I am interfacing with the mains electricity supply, (in this case for using the Arduino to control lights via relays / home automation), I assume that I could run into legal issues in terms of having the work certified by an electrician or the electricity supplier?

I also assume that there may be legal ramifications with the insurance company if something should happen that is related to the home automation project?

In which case my project may stop before it begins.

If anyone has had any experience with this sort of thing, perhaps even here in Australia, let me know. Thanks!!

Well in the UK you only need certification if you are permanently connected to the mains, like a cooker or water heater. If it goes through a plug and socket then you don't.

@edgeman

I talk to an electrician ( he was changing the breaker box / meter box ) and we talk about some of my electrical work inside my place, he said : When something bad happen ( a fire ) , and the inspector find that the cause of the problem ( the fire ) is one of my electrical work I did, Legal charge will be against me, big fine and maybe jail. The insurrance is well .... <-- No money to you ( a big legal loop hole for them to use against you ). He also said that : Any electrical work has to be "To Code" <-- The Electrical Code - Canadian version

I hope you got "my picture". I would say : Do it at your own risk.

Techone:
@edgeman

I talk to an electrician ( he was changing the breaker box / meter box ) and we talk about some of my electrical work inside my place, he said : When something bad happen ( a fire ) , and the inspector find that the cause of the problem ( the fire ) is one of my electrical work I did, Legal charge will be against me, big fine and maybe jail. The insurrance is well .... <-- No money to you ( a big legal loop hole for them to use against you ). He also said that : Any electrical work has to be "To Code" <-- The Electrical Code - Canadian version

I hope you got "my picture". I would say : Do it at your own risk.

Yeah, I was thinking that too, but perhaps if I can get an electrician to install the unit? The good news is that 90% of the system is low voltage (i.e. 9V), running of CAT5 cables, it's just the relay that is connected to mains power.

If it goes through a plug and socket then you don't.

Used to be the same in Oz as well, probably still is.


Rob

edgeman:

Techone:
@edgeman

I talk to an electrician ( he was changing the breaker box / meter box ) and we talk about some of my electrical work inside my place, he said : When something bad happen ( a fire ) , and the inspector find that the cause of the problem ( the fire ) is one of my electrical work I did, Legal charge will be against me, big fine and maybe jail. The insurrance is well .... <-- No money to you ( a big legal loop hole for them to use against you ). He also said that : Any electrical work has to be "To Code" <-- The Electrical Code - Canadian version

I hope you got "my picture". I would say : Do it at your own risk.

Yeah, I was thinking that too, but perhaps if I can get an electrician to install the unit? The good news is that 90% of the system is low voltage (i.e. 9V), running of CAT5 cables, it's just the relay that is connected to mains power.

Edge,

9V over Cat5 isn't an issue. Put a fuse on the power line and you'll be good.

In regards to relays- Pick the right size relay, right size wire, and don't permanently connect it. Put a male plug on one side of the relay that plugs into the wall, a female plug non the other side of the relay, for the device to plug into. AND FUSE IT.

Fuses are your friend.

magnethead794:
In regards to relays- Pick the right size relay, right size wire, and don't permanently connect it. Put a male plug on one side of the relay that plugs into the wall, a female plug non the other side of the relay, for the device to plug into. AND FUSE IT.

Fuses are your friend.

I like your way of thinking! That can certainly be done, two plugs, one on each side of the relay, with a fuse. No why didn't I think of that! :slight_smile:

edgeman:

magnethead794:
In regards to relays- Pick the right size relay, right size wire, and don't permanently connect it. Put a male plug on one side of the relay that plugs into the wall, a female plug non the other side of the relay, for the device to plug into. AND FUSE IT.

Fuses are your friend.

I like your way of thinking! That can certainly be done, two plugs, one on each side of the relay, with a fuse. No why didn't I think of that! :slight_smile:

Not sure how you're planning to wire your structure, but having "sensor drops" here and there may not be a bad idea, even in places you don't think you'll need them. Since you're using CAT5, it's cheap and easy to add a sensor drop with almost every outlet. That way when you expand your horizons (I see you I2C'ing a pair of mega's at some point...), you'll have the connectivity to control almost anything, almost anywhere. Just use some sort of ID to tell internet/ethernet apart from sensor/Cat5. IE, I'd have internet and phone with the tab pointing down, and sensor with tab pointing up.

magnethead794:
Not sure how you're planning to wire your structure, but having "sensor drops" here and there may not be a bad idea, even in places you don't think you'll need them. Since you're using CAT5, it's cheap and easy to add a sensor drop with almost every outlet. That way when you expand your horizons (I see you I2C'ing a pair of mega's at some point...), you'll have the connectivity to control almost anything, almost anywhere. Just use some sort of ID to tell internet/ethernet apart from sensor/Cat5. IE, I'd have internet and phone with the tab pointing down, and sensor with tab pointing up.

You lost me a little there, what do you mean by "sensor drops" ?

edgeman:

magnethead794:
Not sure how you're planning to wire your structure, but having "sensor drops" here and there may not be a bad idea, even in places you don't think you'll need them. Since you're using CAT5, it's cheap and easy to add a sensor drop with almost every outlet. That way when you expand your horizons (I see you I2C'ing a pair of mega's at some point...), you'll have the connectivity to control almost anything, almost anywhere. Just use some sort of ID to tell internet/ethernet apart from sensor/Cat5. IE, I'd have internet and phone with the tab pointing down, and sensor with tab pointing up.

You lost me a little there, what do you mean by "sensor drops" ?

Wherever you're going to have your sensors and relays- to get the wiring out of the wall and to the sensor/relay. Cat5 is cheap enough that you can run a port down with almost every electrical outlet (certainly 2 per room, 1 on each end) so that when you have your entire house runing off a pair of I2C'd megas running over 100 sensors and relays....you wont have to rip out drywall to make it happen :slight_smile:

If you understand basic wiring, how to insulate the circuit, and how to isolate the low-voltage circuit from the high-voltage (relay, transformer, or optoisolator,) I wouldn't worry too much.

I know what's safe and I've done a lot of electrical wiring (for myself and for friends), but I'm not licensed. (I have a brother-in-law who is an electrician, and once in a while I'll ask him about the codes.) I've also built lots of electronics projects, and most of those have included building a power supply, which of course plugs into the wall!

I live in the U.S. so I don't know about Australia, but it generally takes gross negligence or criminal negligence to get you into trouble. If you just make a "dumb mistake", your insurance should cover the damage. If someone gets hurt or their property gets damaged, you are liable for your mistake but your insurance should cover it.

Now, if you playing a game where you drive your car blindfolded, or if you are lighting fireworks inside your house, or if your illegal drug lab catches fire, you might get arrested, and your insurance might not cover it. :slight_smile:

I actually wouldn't worry too much about a fire. If you mis-wire something, or something shorts-out, the likely event is for the electronics to "fry" (maybe get hot and die without a fire) or a circuit-breaker in your house might blow. Everything would have to be "just right" for the device to heat-up, and continue to draw enough current to create a lot of heat and cause a fire, but not enough current to blow the breaker. (A fuse in your device is also a good idea.)

If you do something wrong, it's more likely that someone gets shocked or electrocuted, than to start a fire. So, make sure everyghiing is insulated and wired correctly. :wink:

magnethead794:
Wherever you're going to have your sensors and relays- to get the wiring out of the wall and to the sensor/relay. Cat5 is cheap enough that you can run a port down with almost every electrical outlet (certainly 2 per room, 1 on each end) so that when you have your entire house runing off a pair of I2C'd megas running over 100 sensors and relays....you wont have to rip out drywall to make it happen :slight_smile:

Gotcha, and absolutely agree, I am already thinking ahead to switching lights on / off as people leave certain rooms, using light sensors and temperature sensors to do stuff :slight_smile:

DVDdoug:
If you understand basic wiring, how to insulate the circuit, and how to isolate the low-voltage circuit from the high-voltage (relay, transformer, or optoisolator,) I wouldn't worry too much.

Thanks for the feedback, and yeah, I have thought the same thing. The only thing I've been told about Australia is that the renovation work won't be "certified" (i.e. completed) unless an electrician gives the thumbs up. So, what I am thinking about doing is getting an electrician to put a power point plug in for each light, and then putting a plug on the light to plug into that power point. That way in future I can plug my Arduino -controlled relay switch into the power point, and have the light plug into it :slight_smile:

I have to run that past an electrician, but I'll let them know I'll be putting X10 or something like that in, which works the same way, just usually for bed-side lamps, in this case I am changing from standard hard-wired ceiling lights to having them converted to be pluggable... I'm thinking that should be fine.

:slight_smile:

Im an electrician in nj, usa, and a homeowner is allowed to do their own electrical work, if its alot of work like a renovation that usually means them getting a homeowners permit and having it inspected to make sure its up to code,
but if its like small work like adding an outlet,switch,fixture,etc(home automation relay) a homeowner can do it legally without inspection
needless to say I've been to alot of houses where I've had to fix a homeowners shotty work, so please don't attempt this if you aren't confident in your ability to do a neat safe job
but if you know how to then I don't see any problem even hard wiring your devices(which will probably look nicer compared a plug in ceiling light)
An definetly go with the extra wires, its always better to wire for the future even if you don't plan on using it, it saves tons if time and money in the future if you do use it, even if you bury a cat5 wire next to the outlet so in the future you can cut a hole and retirieve it will work great
Good luck!