I have a project that I am building, for swipe card access to power. I have working solutions and fritzing diagrams but this is more a general query.
I have configured the Phase cable (brown for this locality) into the COM (Common) port of the relay, and the NO (Normally Off) cable leads to the device to be powered on. Is this correct or does the order need to be reversed?
Regards, Ian
If you have to ask that question then you should not be doing the mains wiring for this project
and once I know the answer, I can do mains wiring for this project.....
Where are you going to put the green wire?
NO (normally open) and NC (normally closed) refer the the contact's state when the relay is unpowered, before you've taken it out of the box.
Plus a few years experience.
OK getting lost in translation somewhat here. I have connected the earth wire to the earth wire, and the neutral (blue) wire to the neutral blue wire. I have a diagram provided by some else which shows the 'hot' brown wire from the mains connected to the "NO" (normally off) part of the relay, and the outgoing brown wire to the "COM" part of the relay.
However if I ask mr google about arduinos and relays, it shows a diagram where the 'hot' wire is connected to "COM" and the outgoing is connected to "NO".
So which is it? Regards, Ian
It doesn't matter if the supply line is connected to COM or NO, but convention says COM. It's just an inline switch.
I assume that you understand that a relay is simply a switch. How would you wire the equivalent switch ?
@UKHeliBob: After 37 years working in IT, I assume nothing about technology unless it is specified. I am also smart enough to know I don't know it all, hence the possibly dumb questions.
As for yourself, I assume you did not pick up this knowledge 'in utero' and were not birthed quoting Ohmns law, so had to learn these rules for the first time; try and make others' first time learning less onerous, if you would.
But the contacts of the relay are specified, You posted the specification yourself, albeit not quite right
Should be Normally Open, but if you have ever wired a switch of any kind I would have expected you to understand the wiring of the relay contacts. In your IT role do you not use your experience of one system to inform your use of a second one ?
As for my knowledge, of course I was not born with it. I suspect that the first time I came across a relay when I was about 10 years of age I used my understanding of how a switch works to wire up the corresponding contacts on the relay
It seems that you have now got the answer to your question and can move forward with your project