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Low wattage 110v over 20-22AWG wire?

DanTheMan827

I bought a 5v power supply from china but the holes in the PCB for the AC voltage are extremely small (about 20-22AWG)

 

Is this safe to use with such a thin wire?

 

I mean, my measurements are just a guess but I did try some 18AWG stranded wire and it didn't fit through the hole... (almost)

 

Here's a spec sheet for the PSU http://shop.cpu.com.tw/product/48432/info/

 

I plan on stuffing a NodeMCU, relay, and this power supply into a single gang blue electrical box that will not be mounted inside the wall but instead would be something like an all-in-one powerswitch tail.

 

I plan to use as a Wi-Fi light switch for patio lighting (a series of 12V LED lights) which would be used in place of an existing wall-mounted timer.

 

I was thinking of wiring it up something like this, the 110VAC coming in would be a recycled PC power cord.

 

FlaUmey.png

 

Since it will be inside a electrical box the branch of 110V to the 5v psu would be very short.

 

I would use a wire nut for the neutral wires which would be the light wire, PSU neutral, and the neutral from the outlet

 

Then for the hot it would be the same but the light wire would be passing through the relay instead.

 

Also, would I safely be able to remove some strands of from a thicker wire to fit it through the PCB hole?

Parents
  • 0

    As long as the wire insulation is rated above the AC voltage (usually 300V) and the current used by the LED strip is below what 20 - 22 gauge wire is rated

    for which is 5A (22 ga.) - 6A (20 ga.) for solid wire it is safe. Using stranded wire decreases the current that can be handled by the wire. The current needed

    for the LED strip can be calculated using the wattage of the LED strip which you did not mention in your post but for the wire gauges given using solid wire will

    handle ~ 550W (22 ga.) -  ~ 660W (20 ga.).

     

    The distance of the branch to the 5V power supply would have to be real long for it to matter in this application however the length of the wire from the control

    box to the LED strip should be kept as short as possible assuming current needed by the LED strip is fairly close to what the wire can handle.

Reply
  • 0

    As long as the wire insulation is rated above the AC voltage (usually 300V) and the current used by the LED strip is below what 20 - 22 gauge wire is rated

    for which is 5A (22 ga.) - 6A (20 ga.) for solid wire it is safe. Using stranded wire decreases the current that can be handled by the wire. The current needed

    for the LED strip can be calculated using the wattage of the LED strip which you did not mention in your post but for the wire gauges given using solid wire will

    handle ~ 550W (22 ga.) -  ~ 660W (20 ga.).

     

    The distance of the branch to the 5V power supply would have to be real long for it to matter in this application however the length of the wire from the control

    box to the LED strip should be kept as short as possible assuming current needed by the LED strip is fairly close to what the wire can handle.

Children
  • 0 in reply to gdstew

    The 18AWG power cord coming into the project box will branch off to both the 5V PSU and the relay which will be switching the hot side of the lights (neutral will always be connected)

     

    I don't know the current of the combined LED lights but they are 8 or so 12V automotive LED lights that are rated at 12V / 1.5W each and wired up in what I assume is series since the voltage coming out of the current timer is 120VAC and the individual fixtures appear to just be the wire connected to the bulb socket

     

    The lights are in fixtures that are mounted on the support posts around the porch

     

    The wire going to (and between) the lights looks like 18AWG lamp cord which was originally powering 12V incandescent bulbs of a similar brightness to the current LED lights

  • 0 in reply to DanTheMan827

    Stranded 20 to 22 AWG wire should be OK. I'd go with 20 if you can.

     

    I agree with shabaz about the power supply because after looking through the web page I do not see that it is certified to safety standards in the US or any other

    country for that matter so I am surprised that it can be imported into the US. I also don't see any way to properly mount it in the project box (I assume it is plastic ?)

    because it has no mounting holes.