Disclosure: This post may contain affiliate links.

Will Powerline Adapters Work Between a House and Garage?

Learn about whether Powerline adapters will work between a house and a detached garage or shop.

Powerline Adapter Kevin Jones / TechReviewer

Last Updated: May 16, 2022

Written by Kevin Jones

Will Powerline Adapters Work Between a House and a Detached Garage?

Section Link

Powerline adapters require that each adapter be on the same circuit. If your garage and rooms are on the same circuit, they should be able to communicate via Powerline adapters.

Garage sub-panels should not be a problem, with the other restrictions in mind.

The biggest problem for newer detached garages in the US is the requirement for GFCI outlets on all detached garage receptacles. Powerline adapters will not work on GFCI outlets.

Most Powerline adapters indicate that they will only work when connected to the same circuit. Let's dig into the details of how this works.

How Electrical Panels Are Wired

First, let's discuss how home electrical panels are wired in North America.

Three lines run from the power company's transformer (the thing that looks like a can on a power pole) to your home: a neutral and two hot leads (line 1, line 2).

There are 120 V between line 1 and neutral and between line 2 and neutral.

There are 240 V between line 1 and line 2.

Circuit breakers are labeled for various rooms or appliances on your electrical panel. Circuit breakers limit the current from exceeding the desired threshold to ensure that your wires don't melt.

Lights and outlets in rooms need 120 V, so circuit breakers for those rooms connect to neutral and either line 1 or line 2.

Larger appliances need 240 V, so those circuit breakers connect to line 1 and line 2.

Each row in an electrical panel alternates between line 1 and line 2. Because 120 V breakers only need to connect to either line 1 or line 2, but not both, they take up a single row of an electrical panel's left or right column.

Here's an example electrical panel layout:

Line Left Column of Electrical Panel Right Column of Electrical Panel
Line 1 Circuit Breaker 1 Circuit Breaker 2
Line 2 Circuit Breaker 3 Circuit Breaker 4
Line 1 Circuit Breaker 5 Circuit Breaker 6
Line 2 Circuit Breaker 7 Circuit Breaker 8
Line 1 Circuit Breaker 9 Circuit Breaker 10
... ... ...

Note that lines 1 and 2 may not always be the same for an electrical panel's left and right columns. For example, whether breakers 1 and 2 both use line 1 will depend on the manufacturer.

Similarly, 240 V breakers need to connect to both line 1 and line 2, so they use two rows of a column of the electrical panel.

Legs and Phases

Each of the lines described above is considered a circuit or leg.

With North American "split-phase" electrical systems, communication between legs would go through the power meter and transformer. Going through these hurdles makes communication difficult.

In some countries, where "multi-phase" installations exist, communication between legs is even more problematic.

Powerline Compatibility

Powerline technology is not able to communicate well across legs. The performance impact will be considerable if attempting to communicate across legs. The connection may be intermittent, if it works at all. Communication across phases or legs is often the cause of slower than expected speeds.

Only rooms on the same leg will communicate at high speed via Powerline.

This requirement means that in some cases, you may only be able to use powerline adapters between particular rooms, depending on your home's wiring.

How to Use the Same Circuit

For North American installations, you can use the table above to determine if rooms will be able to communicate. For example, Circuit Breakers in positions 1 and 5 should be able to communicate because they both use Line 1.

However, keep in mind that the same may not be true when comparing the left column to the right column of an electrical panel. Whether breakers 1 and 2 both use line 1 will depend on the manufacturer.

Check out my Recommended Powerline Adapters below.

NETGEAR Powerline Adapter Kit, 2000 Mbps NETGEAR Powerline Adapter Kit, 2000 Mbps Check Price on Amazon Amazon Affiliate Link

Powerline vs. Alternatives

Section Link
Ethernet Cable & Alternatives Setup Complexity Supported Speeds Supported Distance Latency Reliability
Ethernet Cable - Ethernet over Twisted Pair (e.g., Cat 6a) Excellent Excellent Good Excellent Excellent
Powerline - Ethernet over Powerline Excellent Fair Good Fair Poor
MoCA - Ethernet over Coax Good Good Good Good Good
Wi-Fi - Wireless Good Fair Fair Poor Fair

If you would prefer a high-speed connection to your garage and are willing to lay new cable, then I would recommend using a fiber optic cable connected with two fiber to Ethernet media converters. This setup will help to protect your network from lightning strikes. I discuss this more in my article Set Up a Fiber-Optic Network in Your Home or Office and Ethernet Surge Protection for Home Networks.

Learn more about MoCA adapters in my article, Ethernet Over Coax?! A Complete Guide to MoCA Adapters.

Use Cases for Powerline Adapters

Section Link
  • Use existing home wiring as a replacement for Ethernet cables.
  • Extend wireless coverage.
  • Backhaul for a Mesh Wi-Fi System (i.e., a wired backbone for the Wi-Fi satellites).
  • Get Internet access into hard-to-reach places in your home.
  • Use wired connections to avoid Wi-Fi interference from neighbors.
  • Avoid the latency of Wi-Fi while playing games on consoles and computers.
  • A secure alternative to Wi-Fi.

Pros and Cons of Powerline

Section Link

Pros:

  • Easy wiring using existing power outlets (connect an Ethernet cable)
  • Low cost (compared to MoCA adapters)
  • Encrypted (some products)
  • Up to a 300-meter range
  • Some models have built-in Wi-Fi
  • Plug and play setup (no configuration required)

Cons:

  • Often a lower connection speed of around 150-350 Mbps compared to the advertised 1-2 Gbps
  • Powerline devices need to be on the same electrical circuit
  • May cause noticeable electromagnetic interference with some devices such as speakers (static sound)
  • Power strip, GFCI outlets, and AFCI circuit breakers may degrade Powerline network signals
  • Some models block an outlet when connecting directly into a wall outlet
Section Link

How to Set Up Powerline Adapters

Section Link

Powerline adapters can be very simple to set up. Conceptually, you can think of a pair of Powerline adapters as an extension for an Ethernet cable. More than two Powerline adapters behave like an Ethernet hub combined with Ethernet cables.

Most Powerline adapters are configured similarly.

To set up Powerline adapters:

  1. Plug one Powerline adapter into a power outlet and connect it to your Internet router via an Ethernet cable.
  2. Plug one or more additional Powerline adapters into power outlets in rooms where you want Internet access. Connect them to computers or other network devices via Ethernet cables.
  3. Pair the Powerline adapters by holding down the button on each adapter for a few seconds.

That's it! Your devices should now be on the network and have Internet access.

Building Your Network

Section Link

If you want to learn more about internet equipment, networking, wiring, or troubleshooting, check out these articles:

More Powerline Articles

Section Link