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I have some network equipment that I want to connect to ground (they come with 2-prong wall wart PSUs and have a separate screw hole for a grounding pigtail) - but where would I get ground from in a regular home?

For me, the obvious choice would be an existing wall outlet (regular USA 120V 15A NEMA 5-15R). But I don't need the 120V, I kinda just want to get the ground, connect it to a copper grounding strip or bus bar, and then connect grounding pigtails to that.

If that is sane, then I wonder: How would I get the ground out of the wall socket? I guess I could just jam a banana plug or something into the grounding hole, or cut open a power cable and make sure the +/- electrical plugs aren't connected. But that seems hack-ish and dangerous.

But there also don't seem to be "simple" NEMA 5-15R-ground-taps available (kinda the exact opposite of this), which makes me wonder if a) this approach is actually the correct one and b) whether there might be a much simpler/better way to get ground from somewhere in a regular home. (A non-corrosive steel post outside isn't an option really here, no good way to run a wire into the room)

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    \$\begingroup\$ I'm curious what your motivation is for grounding the network equipment. It should, generally, be safe to use it ungrounded - the wall warts powering it should be double-insulated. \$\endgroup\$ – pericynthion Jun 7 at 15:24
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    \$\begingroup\$ @pericynthion Nothing really pressing, but the documentation for one of them says The Switch is grounded through the Power Adapter; however, you can enhance ESD protection by connecting the ancillary ground.. Since I'm racking my home office, it's one of those items that I'd like to do (and have since done) when feasible. \$\endgroup\$ – Michael Stum Jun 24 at 15:38
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I have seen adapters that are exactly what you want. On the side that plugs into the wall they have one conductive prong for the earth connection and two plastic dummy prongs to fit the live and neutral. On the other side they present the earth connection either as a single banana socket or a screw terminal.

So they do exist, but I'm not going to try to find a specific part number for you to order because shopping questions are off-topic. Keep hunting and try using "ESD" as a keyword since these are often used to hook up electrostatic discharge prevention equipment.

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    \$\begingroup\$ Thank you, "ESD" and "plastic prong" search term helped me find what I need! \$\endgroup\$ – Michael Stum Jun 7 at 5:35
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    \$\begingroup\$ Note that ESD bonding points may have a high resistance connection to ground. Example.That's not what you want \$\endgroup\$ – Chris H Jun 7 at 12:28
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You have two common options:

1) A plug that is some variation on the left image. They come in many different designs and price points. Be aware that they may also have resistors on some/all of the sockets which could potentially make some unsuitable for your purposes.

2) Use/install a wall plate with an exposed ground screw as shown on the right. You can then simply screw your pig tail(s) to the socket. This should be the cheapest option for you.

enter image description here

Cheaper would be of course to just make your own plug. There are a lot of options as to how you could build one. Personally I would buy a $2 plug with removable type prongs, take out the live and neutral prongs and replace them with plastic. I would 3D print them, but you could use the removed prong as a stencil and just cut a piece of similar thickness plastic into that shape.

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you're on the right track with safely making use of the ground pin from a standard outlet. I just did the same search within the last couple months and was surprised at how few options there are -- but keep searching and you will find them. I was also surprised at how quickly you can empty your bank account for such a simple device. Follow the advice from pericynthion and search for ESD related hardware. Here is a small collage photo of solutions I investigated. The last image could be easily modified with a banana jack or ring terminal as needed.

enter image description here

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  • \$\begingroup\$ Thank you! Found the bottom two options. Yeah, Pricing is surprisingly high, but cheaper than dealing with a house fire or self-electrocution, I guess :) \$\endgroup\$ – Michael Stum Jun 7 at 6:33
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    \$\begingroup\$ I would suggest you just use the ground screw on your wall plate if you want the cheapest option. \$\endgroup\$ – hekete Jun 7 at 14:11
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The first question you need to ask is what sort of ground do you want and why?

If you want the ground purely for electrostatic discharge protection then ESD grounding equipment is appropriate. ESD grounding equipment contains large resistors to prevent it from passing large currents.

On the other hand if you want the ground for safety* or EMC reasons the ESD grounding equipment will be useless. If what you want is a low impedance safety ground then harper's suggestion of buying a rewirable plug and connecting your wire to the ground terminal is the way to go.

*Either because you don't trust the supposedly class 2 PSUs to actually be class 2 or because you are worried that the leakage currents from multiple PSUs while safe individually could add up to be hazardous.

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  • Go to the hardware store and buy a 3-prong NEMA 5-15 plug for $4
  • Wire your ground wire to it. Wrap the other terminals with tape.
  • Double-check that your receptacle is wired properly
  • Profit!
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  • \$\begingroup\$ Basically what I would do. Though wrapping the terminals with tape seems excessive. It's not like you have to turn the switch on to use the earth prong. \$\endgroup\$ – hekete Jun 7 at 19:10
  • \$\begingroup\$ @hekete because it will be difficult to fit a proper strain relief on a single wire; if you manage to rend it out of the plug, you don't want it touching hot or neutral on the way out.. \$\endgroup\$ – Harper Jun 7 at 22:55

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