It's well-known that GFCI outlets can cause issues for powerline networking. However, is this true even if the powerline adapter is plugged in upstream of the GFCI outlet (i.e., on the same circuit, but between the panel and the GFCI outlet)? It seems to me that in this case the GFCI outlet should have no effect, but I can't find any explicit statements to this regard.

I'm planning to put a new circuit in that would be set up like this (panel => outlet for powerline adapter in basement => GFCI outlet for outdoor lights), but I want to make sure I won't regret it later. I can put in two separate circuits if need be, but since they would run in exactly the same location, that seems like a waste.

2 Answers 2


Power line network adapters will have at least two plug in module units. There may be more if you are having additional network drop points.

If there is any truth to the rumor that a GFCI could be a problem for a power line network adapter it would be if the adapter had to send its RF signalling through the GFCI unit between two of the adapters. Therefore the particular concern, if one indeed exists, would be that all of the power line network adapters would need to be situated on the same side of the GFCI. So:

  1. If all of the power line network adapters were all on the load side of the GFCI there should be no problems.
  2. If all of the power line network adapters were on the main breaker box side of the GFCI then there should be no problem.

You do have the somewhat unrelated issue that sometimes if power line network adapters have to bridge from one of the 120VAC phases to another 120VAC phase there will be attenuated signal due to poor coupling between the phases. Suppliers do sell capacitor coupling units that can be installed in the main breaker panel to supposedly solve this problem, however even this issue has to be taken with some grain of salt.

  • Thanks. I am already using the power line network adapters, with both on the "inside" (panel side) of the house wiring, and they work well. The same will be true once the new circuit is in place. None of the adapters will be on the "outside" (load side) of a GFCI outlet, so per your answer, sounds like I won't have an issue. Nov 16, 2018 at 5:47

GFCIs don't care about anything happening on the LINE side. On the LINE side, GFCI can't influence anything.

The dominant feature of a GFCI is a current transformer. Hot and neutral are wrapped around a core, in the same direction so their (opposite flow) currents cancel out the magnetic field. If not, current is leaking somewhere else. Trip! Of course this is also a toroid/choke. Signal can't get through that.

Since this is a GFCI's core design, there is no such thing as a signal-friendly GFCI.

Your solution will be fine. I would push out the junction box to a 2-gang and put the plain receptacle and GFCI right next to each other. Feed the outlet first, then the GFCI. Then feed outdoor receptacles from the GFCI's LOAD terminals. That way the outdoor outlets will be protected, but the GFCI will be indoors where it will last. GFCI's do very badly outside.


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