Super beginner question to do with an AC power supply
I bought this little power supply from Mean Well (reputable maker) that fits nicely on to a perf board that I'm mounting on aluminum hex standoffs. It's the one in the first two pictures below. Here's the power supply data sheet: http://www.mouser.com/ds/2/260/IRM-15-SPEC-806085.pdf
I disconnected a spliced mains wire that I had connected to a bigger power supply. It has a black "live / l" AC wire, a white "neutral / n" AC wire, and a green "ground" wire.
My two questions are:
**1). Where should I connect the green "ground" wire? There is no ground pin on this particular IRM-15 power supply. I believe on the bigger one, the grated metal case serves as the ground. ** 2). Could I connect the green ground wire to a piece of metal that I would then use as "common" ground for my project? 3). I was planning on soldering the pins/wire connections to the perf board, and covering the connections with heat shrink plastic melted with a heat gun. Will this work?
If your talking about the module, it DOESN'T HAVE AN EARTH GROUND because the EARTH ground gets connected to the metal box the circuit board goes inside of. If you have a plastic box, then you have no place to connect it.
IMO, I would connect the green earth wire to the metal enclosure if there is one.
If no metal enclosure heat shrink the wire and secure/isolate it with a tie wrap.
Covering the inputs with glue is something I have done.
Super beginner question to do with an AC power supply
I bought this little power supply from Mean Well (reputable maker) that fits nicely on to a perf board that I'm mounting on aluminum hex standoffs. It's the one in the first two pictures below. Here's the power supply data sheet: http://www.mouser.com/ds/2/260/IRM-15-SPEC-806085.pdf
I disconnected a spliced mains wire that I had connected to a bigger power supply. It has a black "live / l" AC wire, a white "neutral / n" AC wire, and a green "ground" wire.
My two questions are:
**1). Where should I connect the green "ground" wire? There is no ground pin on this particular IRM-15 power supply. I believe on the bigger one, the grated metal case serves as the ground. ** 2). Could I connect the green ground wire to a piece of metal that I would then use as "common" ground for my project? 3). I was planning on soldering the pins/wire connections to the perf board, and covering the connections with heat shrink plastic melted with a heat gun. Will this work?
Number 2 is the correct answer if the metal plate is inside what ever box your project is going into. Also, be sure to observe the correct line connections to the power supply unit. The Line connection goes to your black wire and the common connection goes to your white wire. All, if your house is correctly wired!
A "metal plate" is of no value at all. The Earth ground is for protecting the user by grounding the metal case. It has absolutely nothing to do with the electrical operation of anything.
If everything is insulated you only need live and neutral. The module is UL approved to insulation class II,
but the underside of your circuit board won't be, so you have to ensure it cannot come into contact with
anything else metallic. Adding a plastic insulating screen mounted on the rear of the baord to stop finger
access to the mains wiring would be a wise precaution.
You can mains-earth you low voltage ground if you want, but full isolation is probably better, since earth
faults in the building can cause brief voltage spikes on the earth wire (in the short period of time
before a fuse blows). Most small consumer electronic devices rely on full isolation these days. Big
metal boxed items (washing m/c etc) are earthed to prevent disasterous consequences of internal wiring
coming adrift and touching part of the machine or its case.
There seem to be differences in the approved / recommended practices depending upon which territory you are in.
Here in the UK, I would connect the protective ground / earth to any chassis metalwork, and also (optionally, but preferably) to one or other of the output terminals, normally the negative terminal.
Here in the UK, I would connect the protective ground / earth to any chassis metalwork, and also (optionally, but preferably) to one or other of the output terminals, normally the negative terminal.
Earth to DC GND is probably the only thing that would be of any use in this case since the OP does not appear to have a metal enclosure. Mounting everything on a metal base plate connected to Earth is better than nothing but still not much help.
If the OP MUST use plastic, I would STRONGLY suggest going with clear acrylic instaead of opaque black plastic because at least you can do a visual inspection of the wiring prior to power up to look for loose wires. Clear 1/8" or 1/4" acrylic isn't that expensive . I've cut it with a hacksaw but you have to be very careful not to crack it.
