Technology gives us numerous capabilities in our daily lives, but it also creates issues when connected to sources improperly. Ground loops are a potential problem when setting up a system of devices, and it’s best to avoid these conditions whenever possible. Read further to find ways to avoid ground loops in your electrical system and keep your devices safe and secure from side effects.
What Is Grounding?
Grounding is an important part of any electrical system and remains in effect whenever we use a device. In an electrical circuit, a device plugged into the wall will receive energy from the outlet and transfer it to the devices that need electrical power. The electric current will then return to the source.
This electrical supply continues and may build up over time to dangerous levels. The electricity needs to transfer to a neutral source, and this is where grounding becomes relevant. When a device is grounded, any excess electricity that builds up will flow into the grounded source and decrease voltage. The current will always attempt to flow back to the source or through the current with the least resistance, which is a nearby transformer in most houses.
Grounding is an essential measure of safety that keeps people safe from electric shock as the electricity builds up. A grounded source is important, but you need to proceed with caution when connecting grounded devices.
What Is a Ground Loop?
While devices are grounded, they must remain grounded to one source instead of individual ones, which may create a ground loop. A ground loop is the result of two or more devices having their own grounded source and sharing a connection via a grounded cable.
The electric current from the source runs through the system and has multiple paths to follow instead of one, thanks to the connection between devices and the ground. The current will flow through one device, into the grounded cable that leads to the other device, and into the grounded source.
The current will make its way back to the source and repeat the cycle continuously, creating a ground loop. While the loop occurs, the other pathway that leads from the first device into the ground source will still function as it should, but some effects will occur with the loop’s presence.
Why Are Ground Loops Bad?
Even as the devices continue to function, the ground loop will still affect the surrounding area. One of the primary effects of a ground loop is the loud hum you hear from the devices. The electric current moves so fast that it creates a sound that’s too fast to hear as it decreases in voltage when it reaches the grounded source. The loop causes that current to continue flowing perpetually, creating a steady sound we hear as a high-pitched hum.
While this noise isn’t always the most disturbing, other effects include disruption and interference. If you have a ground loop in an area such as a data center or server room, you may experience gaps in connectivity and spotty reception.
What Cables Cause Ground Loops?
Most cables manufactured today have grounding or will connect to a ground wire in an outlet. Cables used in sensors, data or telecommunication, and power supply carry the chance of causing a ground loop when connected to a device with its grounding.
Because of the popularity of these cables, it’s important to remain aware of your system of devices to avoid creating a ground loop by accident. Plan before setting up devices and use other methods to prevent an improper connection that may create the loop.
Ways To Avoid Ground Loops
Despite the possibility of ground loops, there are ways to avoid them and prevent interference from occurring in your system. These methods will be an important step before you power on any devices in a multidevice system; make sure you use them when applicable and with proper precautions, so they work properly.
Connect Separate Devices to One Grounded Source
One of the most common mistakes people make when setting up a system with multiple electronics is connecting each device to their own grounded source, and then connecting the devices to each other. Having multiple grounded sources will open multiple pathways for the electric current, including a path that causes a ground loop.
The easiest way to avoid a ground loop is to connect devices to one grounded source and not connect them. Each device will become its circuit and will only have one path for the current to follow that leads back to a grounded source before finding its way back to the source.
Audio equipment is normally susceptible to ground loops, and the electronic hum is more prominent in these devices. Ground lift is a function on most audio devices, such as speakers, that disrupts the ground loop and eliminates the hum.
A ground lift switch disconnects the ground pin inside an audio cable and disconnects the device connection. The equipment will still have its own grounded sources but won’t have the connection that causes the loop.
Power Isolation Transformer
Another way to avoid ground loops in running cables is to isolate the current between the grounded source and the device. This type of transformer supplies power to a device while preventing the connection to other devices.
If the current becomes isolated, it won’t run through the other device and cause a loop. The device will still have power and grounding and maintains safety for those around the device.
Audio Isolation Transformer
This transformer is similar to the power transformer but isolates the audio signal. Using this device will work best with audio devices and reduce any excess sound in certain instances, such as ground loops.
The audio isolation transformer cuts the current running through the sound cable and discontinues the loop. Both audio and power isolation cables work well in disconnecting the ground loop while keeping the devices functioning. However, implementing both will cause a decrease in performance and may slow down audio and video quality.
Ensure the Drain Wire Isn’t Grounded at Both Ends
The drain wire is the part of the communication cables that connect to the grounded wire when plugged into a source. A cable connecting to two devices must not have a grounded connection at both ends to avoid ground loops while running the cable. If both ends of the drain wire in a shielded cable connect to a grounded source, multiple paths will open for the electric current to pass through.
Disconnecting the shield at one end or causing it to float is the easiest way to avoid this connection. Opening the cable jacket and placing shrink tubing over the shield will disconnect it from a grounded source. In certain applications involving VGA cable accessories, the grounding pin is usually connected to the grounded source at both ends, requiring you to remove one pin from one end to prevent a ground loop from occurring.
We must avoid feedback and interference in our devices, as ground loops are a problem in grounded applications. The abovementioned ways will give you the edge to prevent ground loops and keep your electrical systems functioning without the annoying hum in your ear.