Is 5v really dangerous?

Quick safety lecture…

Pixel light shows like ours run on either 5v or 12v DC. Because this isn’t “scary” mains AC voltage (110-120vac in the US), some folks don’t think it is dangerous.

Well, here is the thing: Electrical current is measured in Amps. An amp is an amp, regardless of the voltage.

It takes .1A to kill a human.

Less than that can still cause burns and other medical issues.

There is a false sense of security when it comes to low voltages. Our skin protects us to some extent because it takes higher voltages to pass a significant amount of current through it. So, it’s a lot easier for significant current to flow through your body at 120v (or more) than at 5v or 12v.

Here is a bit more of an explanation:

A very real danger comes into play when our skin gets wet! It becomes significantly more conductive. It is even worse if there is salt or other contamination in the water, which makes the water itself more conductive. For Chirstmas lights in the US- we are dealing with winter conditions, with snow or rain and wet ground, resulting in damp hands and other extremities. Wet feet and salt from roads tends to make us well-grounded, and conductive, as-well and wet gloves can present more of a danger than bare hands.

A 5v light show like ours typically runs on 60A power supplies! That’s 600x lethal current.

A 12v show, preferred by some, typically uses 29A power supplies, only 290x lethal current, BUT the higher voltage makes it easier to bridge that current.

So, coming into contact with any of these low voltage circuits under the right conditions CAN KILL YOU. So- while 5v doesn’t sound like much- it is very important to respect it at these high currents.

All of those power supplies also require 120V AC power (higher in other countries). Electrical codes require that outdoor circuits utilize GFCI (Ground Fault Circuit Interrupter) outlets or breakers. These provide protection from electrocution from those AC circuits. While we do use GFCI protected AC power, some others may not. Some older homes or homes with substandard DIY electrical work may not be wired in accordance with the electrical codes. In any case, you should never count on a GFCI to fully protect you from lethal current. You can easily be electrocuted by an extension cord or conventional AC Christmas lights on wet ground. It is also important to note that GFCIs only protect the AC side, and that protection does NOT extend beyond the DC power supplies. You are NOT protected from the DC current, even if the AC is protected!

So, be careful out there! Disconnect the power before working on anything, and use care walking around an energized display.

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