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I used a powerline adapter like this to connect my security camera receiver to my router. This allows me to access the cameras from my cell phone which was working but now it doesn't. There's two things that may have caused this. 1. The receiver was unplugged for a while which may have affected the settings on the receiver. 2. The other powerline adapter was moved to a different circuit.

The settings on the security camera receiver look fine although it's possible the ip address changed and the phone may need to be re-connected.

I know the easy answer here is just plug the powerline adapter back into the old outlet. Unfortunately that outlet was removed because it wasn't code compliant.

Edit: Photos of the panel showing the which circuits the powerline adapters were/are now plugged in to. Panel label circuits identified

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    Unfortunately this is product-specific (and only tangentially about home improvement in the first place). You'll have to read the specs for your unit. – isherwood Jan 16 at 15:56
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    Which circuit breakers control the two circuits in question? Cut up a Post-it note to make flags, stick them on your service panel to mark the breakers, shoot us a photo of all the switches on the panel, and edit it into your question. – Harper - Reinstate Monica Jan 16 at 16:31
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    @Harper - I'll do that tonight – Platinum Goose Jan 16 at 16:59
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    I have had some luck on L1 / L2 if the distance was not two far. But I don’t remember being able to pair them unless they were on the same leg. For the cameras I have on my shop and tack room I do have them on the same leg as they are On the edge for distance. – Ed Beal Jan 16 at 20:22
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    You have two problems. Stop trying to solve them together. Start by confirming that the devices work when on the same circuit, and ONLY then progress to different locations. You could even plug both powerline units into the same multibox temporarily for testing. – Criggie Jan 17 at 6:06
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I did the unthinkable, and started to read the manual for the product you linked, and in the troubleshooting section there is a theme:

Try another wall socket and make sure all powerline devices are on the same electrical circuit.

If you search the PDF for "circuit" you find this phrase several times. I didn't find where the manual lists using the same phase or circuit as a hard requirement, but you can infer from the troubleshooting that they fully expect you to use the same circuit, which I think is a "dumbed down" way of saying it should be the same phase/leg.

I also found this in their FAQ section:

Q3.5: Can Powerline adapters work if they are separated by different electric circuits?

A: No. If they can pair in the same room, but the powerline LED turns off when you move one powerline device to another area, this usually means they are plugged into separate electrical circuits, preventing them from communicating. Please try different locations.

I think they are being a little concervative, because I do have powerline adapters on different breakers, and they work reliably.

Netgear is more optimistic, which muddies the waters a bit because most of these devices are based on the same protocols and theorys:

Can powerline be used in homes across multiple phases?

Yes, but you will either suffer a noticeable loss in performance, or if the signal is too low the units will not be able to communicate.

Finally the Homeplug (standard the devices use) wiki page states:

One of the greatest technical challenges was finding a way to reduce sensitivity to the electrical noise present on power lines. HomePlug solved this problem by increasing the communication carrier frequencies so that the signal is conveyed by the neutral conductor, which is common to all phases.

In conclusion, the answer appears to be a big "Maybe".

  • In my experience (with Homeplug AV hardware), being on the same circuit can really matter a lot, compared to having to go all the way up to the panel, through a pair of fancy *FCI breakers and all the way back again. Also, I'd guess the panel is where a lot of the signal gets lost by leaking into all the other circuits (and a lot of interference comes in instead). – TooTea Jan 16 at 20:05
  • @TooTea, I admit that I have an older home with no fancy breakers, and I'm using the adapters for low-throughput applications. They do work reliably, but I've never cared about what speed they are getting. I think the home run to the panel and then back out to the other adapter is the biggest issue with separate circuits. And another admission - one of the adapters I use is very close to the main panel so that probably helps too. – JPhi1618 Jan 16 at 20:08
  • Aren't both legs ultimately connected to the same coil in the transformer @ the street? i.e., they are actually wired together? So maybe some models can manage to work through all that while others can't. – UuDdLrLrSs Jan 17 at 0:16
  • Does "circuit" in this context mean "different phase from the utility", or "a different circuit from your electrical panel, but on the same phase"? – Alexander - Reinstate Monica Jan 17 at 3:19
  • @Alexander-ReinstateMonica circuit would mean the exact same breaker. Same circuit is will be the shortest wire distance from plug to plug. If it’s a different circuit, regardless of phase the signal has to go all the way to the main panel and back which means a much longer wire distance. – JPhi1618 Jan 17 at 3:53
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Cross-phase communication for power line carrier products can be a challenging problem. (see a white paper from Intellon, a manufacturer of PLC devices, there.) You may be able to improve the coupling between phases, at least for a short time, by turning on an electric-powered heating appliance such as a range, oven, clothes dryer, or water heater. If connectivity improves while one of those appliances is heating, that's an indicator that the two modules are not on the same phase.

If you conclude that the devices are not working well because they're on different phases, there are three things you could do to improve the situation:

  1. Relocate one of the devices in hopes of randomly choosing an outlet on the same phase as the other device
  2. Re-arrange circuit locations in the breaker panel so that the chosen outlets are on the same phase
  3. Install a cross-phase coupling device (if you can find one).

The reason why a high-power heating appliance may temporarily improve the connection is that such an appliance can be thought of as basically a low-value resistor. The high frequency signals used in PLC can travel from the transmitting device through wiring to the breaker panel, out to the heating appliance on one phase, through heating element, return on the other phase, and from there out to the receiving device on that second phase. This path can have lower loss than other paths that might exist between the phases.

As was mentioned in comments, this is most commonly applicable in the US and other countries where multi-pole service is found in a residence. However, it's equally applicable anywhere multi-pole or multi-phase service is found: find some heating appliance that is powered between the poles/phases and turn it on to see whether it improves the PLC communication.

  • "You may be able to improve the coupling between phases, at least for a short time, by turning on an electric-powered heating appliance" Do you happen to know why? – Mast Jan 17 at 6:48
  • I assume because they're 240V appliances which get that 240V by going across phases. – user3757614 Jan 17 at 6:59
  • That would only work in the US – Rsf Jan 17 at 9:59
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    it might work in many other regions, too: "go to the workshop outhouse and turn on the buzz saw, I'd like to use the PLC." – dlatikay Jan 17 at 16:40
  • @Mast - The US 240V is the center tapped transformer, where 120V+ and 120V- are the other ends. So if you flip on a 240V device you're 'skipping the neutral', thus coupling both phases. The signal can propagate between the two easier. – J.Hirsch Jan 17 at 17:40
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American residential power is usually two split-phase legs off a power pole mounted transformer with a center-tapped secondary winding. The center tap is connected to the house neutral. You'll get the best connection if your two powerline adapters are on the same circuit, but you have a good chance of them working even if they are not on the same circuit as long as they are on the same leg. And since there are only two legs in a normal house, you can probably find a workable outlet with a little bit of trial and error. Even better if you understand how breaker panels work, you can then try only outlets that you know are on the same leg.

What is unlikely to work is to have powerline adapters on different legs. This requires the signal to go through the power pole transformer and such transformers are not able to carry the frequency band required.

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    If it's having to go to the power pole transformer, it's also going to have to go through the meter (twice, once outbound and once inbound) so the attenuation will be even bigger. I've tried a similar setup in the UK from annex to house where there isn't a power pole transformer and both are on a common feed and two meters were enough to attenuate the signal to unreliability. – houninym Jan 17 at 9:10
  • Good point, another reason to avoid trying to hop from one leg to the other. – Philip Ngai Jan 18 at 17:45
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There are devices designed to allow this to work, and to not endanger you while you install it. (This one is just the first I found, there are probably cheaper ones.)

In the early days of powerline communications, they just suggested installing a small capacitor joining the two sides of the circuit. It must be able to take 240V, and to be small enough to pass the frequencies involved. Installing it is dangerous unless you are very careful.

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