Is amperage constant or relative to the device?

Question

I have a pull chain ceiling light, very small.

The pull chain mechanism broke. Instead of buying a new mechanism I decided to try and do some Arduino experiments. Prior to that though I need the light to work because it's actually the light by which I solder and work.

So, I removed the pull chain mechanism (similar to this) added in some TL-6 Wires with alligator clips on them and attached that to a small switch. Just to get me up and running.

Shortly after doing this though that little voice in my head started voicing concerns. I have only ever used these wires for small projects. They have a very small gauge and I am worried that if to much is pulled through them there could be a fire.

I researched the wires and it says they can take a max of 1.5amps. Home electrical lines can send up to ~20 amps in the United States. My multimeter, assuming I am using correctly says that there is only 22 mila-amps going through the wire.

SO my questions are:

1. Should I immediately disconnect this and be thankful I'm not talking to my insurance company right now?

2. Do devices determine the amount of pulled amperage?

3. Does it sound reasonable that this like is only using 22 mA?

Answer 1

You should immediately disconnect this and be thankful nobody got electrocuted and your liability insurance company didn't find out about your wiring.

The current that light draws is small enough that it should be no issue for those wires. 22 mA sounds too small, so either this light is much smaller than it seems from the picture, or you are measuring the current incorrectly. However, it would have to be a 115 W light just to draw 1 A, so that's not the problem with your wiring.

The 20 A rating means that's the maximum the circuit can supply without the breaker popping or the fuse blowing. Each individual appliance decides how much current it will actually draw.

The problem with your setup is safety. You have dangerous voltages exposed. It is too easy for you to accidentally touch one of the live wires while some other part of your body is connected to ground. That would hurt and shock at the least, and could kill you under the right circumstances.

If you want to rig up this switch yourself, turn off the breaker, solder the wires properly, then wrap everything carefully with electrical tape so that no conductors are exposed. If done right, that would still only be safe in a practical sense but not a legal one. If someone gets zapped, even due to something else, or your house burns down, your kludge could give the insurance company the excuse it needs to not pay. Even worse, you could be legally liable for someone's injury, even if your kludge was not at fault. I'm no lawyer, but assume you'll have a uphill battle to prove your kludge was not at fault, rather than the other side having to prove it was. This can be what happens when you make illegal modifications to power wiring.