Safety Advice for Electromagnetic Fields (PDF)
Language: English | Chinese(中文)
Safety Advice(PDF)
English | (中文)



Grounding Electrical Appliances

Below are instructions for grounding electrical appliances.

Note that these instructions assume that you are using a properly grounded outlet. This can be tested with a cheap outlet tester.

How to Ground a Lamp

Note: Newer versions of Firefox no longer support Vimeo videos. If you have trouble viewing a video listed below, you can try using a different browser, such as Internet Explorer.

To ground a lamp, first make sure to choose a lamp with metal continuous from the base metal screw to the socket, and with a polarized plug (of the top 2 pins, one pin is bigger than the other). The grounding wires will be connected to the base screw.

Tools and Parts

—Shielded, grounded 12' AC power cable, low outgassing and RoHS-certified

—Wire stripper

—Wire nuts

—Wrench, to loosen base screw of lamp

Black = Hot, Connects to lamp's hot (the same side as the smaller lug)

White = Neutral, Connects to lamp's neutral (the same side as the bigger lug)

Green = Ground, Connects to lamp's base screw, assuming it is continuously metal to the socket

Silver = Ground, Twist with Green, and connects to lamp's base screw

How to Ground a Laptop or USB Hub

grounding a laptop

If your laptop is connected to the power outlet via a power cord with a 2-pin plug, this may result in high body voltage measurements. Alternatively, if your mobile device is connected to a USB hub which is connected to a power cable with a 2-pin plug, you may also measure high body voltage. In such cases, you can unplug your laptop's charger or your mobile device's charger and instead use your device on battery. This is one way to reduce your exposure to electricity. However, if the battery life is not adequate, you can try to ground your laptop or USB hub while charging your device, to avoid exposure to high body voltage measurements. To do this, you can obtain a grounding cord for the laptop and connect it to a metal interface on the laptop or USB hub, such as the USB port.

Note: If the laptop's power cable already has a 3-pin plug, the laptop does not need to be grounded.
Alternatively, if the laptop or USB Hub is attached to a monitor or other device whose power cable has a 3-pin plug and is connected to a properly grounded outlet, it is already grounded indirectly through the monitor.

How to Ground a Device via the USB port

2021 Update: Less EMF now provides a USB ground cord which can be plugged into your computer's USB port or your multiport hub's USB port. Hence, it is no longer necessary to follow the DIY steps below to create your own.

Original Instructions: Below is a grounding cable from Less EMF. Although you could make your own grounding cable, it is not expensive to buy. The grounding cable only makes use of the grounding wire-- hot and neutral wires should not be present, or if they are, they should not be plugged in. One end has the ground plug. In some cases, the hot and neutral pins are removed from the plug. In other cases, the hot and neutral pins are still present in the plug, but are not wired past the plug of the cable. In the example below from Less EMF, there is only one thin wire coming out of the head.

The metal ring on the other side of the plug can be inserted snugly in the upper portion of the USB port, although it is a little hard to fit in. For easier insertion, you can remove the ring terminal and crimp on a spade terminal instead with the help of a wire stripper and crimper for ease of insertion.

You can now insert the plug into the outlet and insert the spade terminal into the USB interface of your computer shown below. You can squeeze it on the top part of the USB interface, so that it is fit snugly and touched to the metal of the USB interface. If you run out of USB ports as a result, you can connect the metal terminal to a USB hub which is connected to the computer.

Caution: Some computers may temporarily shut down, or possibly even break, when plugging in the grounding cable. If you ground your laptop, you do so at your own risk. Note also that while it can be helpful to ground electrical appliances, do NOT attempt to ground yourself in a high electrical environment. For more info, see Electric Fields.

Note that the electrical ground may itself be contaminated with induced voltages or "dirty" electricity-- thus, some recommend to ground electrical appliances to a copper rod in the earth instead. Always check your grounding with meters to make sure it decreases body voltage without increasing intermediate frequencies.

How to Ground a Router or Switch

2021 Update: It is now possible to buy a grounding cable to ground your router, switch, or Ethernet cable.

Less EMF provides an item named Ethernet Bus Ground.

The Ethernet Bus Ground can plug into a router or switch on one end and a 3-prong grounded outlet on the other end.

© 2010-2023 All Rights Reserved | Liability Disclaimer
About | Contact | Links