Shop Talk – So This is why a Floating Ground is BAD!

In this episode, we will be following up on our previous discussion (see more here: around the electrical risk and 3D Printers (machines in general) as after a lot of discussion on this thread, the general opinion is the issue Angus experienced was one of a “floating ground” and a Y capacitor. Yet what is a “Y” capacitor you ask? Well Y-capacitors are designed to filter out common-mode noise, and are connected between line and chassis (i.e. ground) to do this. When the earth ground is lost, this voltage can become stray and cause a “touch current” which is more an announce than harmful (because of the low current) yet is an indicator that your earthen ground and therefore your electrical safy has failed.

Also keep in mind for Angus, his mains are 220v as opposed us in North America at 120v. This means he will see a higher stray voltage (around ~70 volts) and because “volts” represent electromotive force, this mean a high likelihood of feeling a shock. The other thing as we discussed in the video, by adding printers (machines in general) to a power strip without a ground, you will be increasing the current (because the voltage will remain parallel) so this can compound the experience.

Note: (1) these types of tests should not be performed unless you are an experienced professional and have been train to work with such voltages and currents as they can be deadly (yes I have had a family member killed by 110v it happens!). Second, I tried to keep this video simple and descriptive and NOT academic so please don’t waste your time nit picking.

You can see Angus’s video here (I got shocked by a 3D Printer: ) and I recommend watching if you have not seen it. As in this episode we dig deeper into this potential issue as basically all 3D printers in this type/class work the same. So we will talk about what could go wrong to cause this as well as what precautions to take to avoid these risks!

Also, here is a video which I created a while back on grounding and the CO2 laser which is also relevant in general to concept of grounding machinery:

Safety Tips!
1. Avoid the use the residential power strips period, if you feel compelled to use a power strip, use an industrial grade such as this or

2. Ensure your home has a working ground! I can’t stress this enough and you can test it with a simple tester such as this:

3. If need to use an extension cord, use an industrial grade of say 16 to 12 gauge. Better yet, use something like this (it come various length) to avoid the need of an extension cord all together

4. If you are shocked, unplug the device or suspected devices immediately until the source of the problem can be found and resolved!

Interested in getting your own JGAURORA A5 Creality CR-10 killer 3D Printer? Well check out the deals on Gearbest for them here as these folks have been great to work with and are huge supporters of the 3D Printing community!

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