How to tell if mains sockets are on same circuit?

[OttoF]

Is there a safe and easy (but also precise) way to tell if two separate mains sockets are on the same circuit?

I need to know because I'm trying to use existing mains circuitry to create an ethernet network in a communal area of a multistorey block of flats, using Powerline Adapters.

Unfortunately, I can't just go flipping breakers at the consumer unit to test what stays powered on, as there is door access, CCTV, fire detection, etc. all connected to the main consumer unit.

It's a one-off job, and I'm on a budget, so professional (expensive) equipment is not an option, but I can stretch to buying a small bit of kit if required. I have some general DIY electrician tools (basic multimeter, etc.).

Any suggestions are welcome. Thanks.

P.S. using WiFi extenders is (unfortunately) not an option due to the location and lack of mains sockets, and I'm desperately trying to avoid running network cabling as a solution.

 

[SparkyChick]

Without isolating them or tracing all the cables physically, I'm struggling to think of a way.

If you know a spark with a circuit tracer, that may help.

Do you mind me asking, what is the network for? And how big an area are you looking at?

 

[Marvo]

You get a piece of kit called a circuit breaker locator or circuit breaker finder. It consists of a small transmitter you plug into the live socket and a reciever unit that makes a squaking noise. You move the reciever along the row of circuit breakers in the CU and the racket it makes gets louder as you get closer to the breaker that supplies the cricuit that the transmitter is plugged into.

It's not 100% foolproof, sometimes it's not easy to know for sure if it's the circuit you're looking for but the hit-rate for the cheap one I have is probably 95% of the time.

Here's a link to an example, it's probably the kinda thing you'll find in abundance on EBay.

 

[Strima]

As it’s multistory you may we’ll find the installation is three phase so there’s s very good chance the circuits may not be on the same phase.

Powerlines don’t need to be on the same circuit to work but they do need to be in the same phase.

 

[Spoon]

Is there a safe and easy (but also precise) way to tell if two separate mains sockets are on the same circuit?

I need to know because I'm trying to use existing mains circuitry to create an ethernet network in a communal area of a multistorey block of flats, using Powerline Adapters.

As above. Powerlines done need to be on the same circuit. Mine at home are on different circuits, but same phase.

 

[MJPD29]

Plug in a socket tester, turn one breaker off, and continue process. If they turn off on the same breaker they will be on the same circuit. If one goes off and the other doesn't they won't be

 

[Deleted member 26818]

Get a socket tester that beeps when there is no power to the socket, so you can hear the socket is off from a distance and don’t have to go back to the socket and check the LEDs on the tester.
To check whether two sockets are on the same phase, you need to use a voltage tester or multimeter.
Using some kind of adapters, connect the two probes to each of the sockets live pin receptacles.
If the measured voltage is 400V, then they are on different phases.
If the measured voltage is 230V, then you have incorrect polarity on one of the sockets.
If the measured voltage is zero, then after confirming each socket has power, they are on the same phase.

 

[mhar]

Those powerline things kick out massive amounts of rf interference, you will wipe out your fm and dab reception

 

[Octopus]

I would forget this idea ............... there are too many pitfalls ........ Powerline are normally OK in single phase properties .......... but I've seen them struggle between RCD's

So if you have 3 phase, RCD's and long circuits ...............

Just saying

Whats this for BTW?

 

[littlespark]

Rereading the OP, the socket circuit should be marked, so there should be no risk in turning off cctv, alarms etc.

If it’s only around 1 communal area, and the server/ router is in the same place, power line should work ok, but same reasoning, Wi-fi should work too.

Are the sockets themselves marked up with a label with a circuit number on them?

 

[Pete999]

fuse finder | eBay - https://www.ebay.co.uk/sch/i.html?_nkw=fuse+finder&ul_noapp=true
Fuse finder like these

 

[PEG]

Is this addition a requested feature,by all the tenants,or a surprise Christmas present?

 

[OttoF]

Without isolating them or tracing all the cables physically, I'm struggling to think of a way.

If you know a spark with a circuit tracer, that may help.

Do you mind me asking, what is the network for? And how big an area are you looking at?

Unfortunately, the only electrician I know would be looking for a fee. As I'm still testing solutions, I'll only use him if I know interrupting the power supply will happen for sure.

The reason behind all this is due to CCTV upgrade to a system that has internet connectivity allowing users to login remotely.

The costs involved in installing and maintaining a dedicated broadband connection for the CCTV are prohibitive. The plan is to use an existing broadband connection from one of the properties.

 

[OttoF]

You get a piece of kit called a circuit breaker locator or circuit breaker finder. It consists of a small transmitter you plug into the live socket and a reciever unit that makes a squaking noise. You move the reciever along the row of circuit breakers in the CU and the racket it makes gets louder as you get closer to the breaker that supplies the cricuit that the transmitter is plugged into.

It's not 100% foolproof, sometimes it's not easy to know for sure if it's the circuit you're looking for but the hit-rate for the cheap one I have is probably 95% of the time.

Here's a link to an example, it's probably the kinda thing you'll find in abundance on EBay.

Brilliant. That's exactly the type of thing I hoping was available. Followed your link and found a different brand for just £30 delivered (eBay seller).

Thank you so much.

 

[Octopus]

Shame the OP didn't update us when he viewed the thread...

 

[Spoon]

Shame the OP didn't update us when he viewed the thread...

Do we have spy software..

 

[Octopus]

Do we have spy software..

No. You can see this on a persons profile

 

[OttoF]

As it’s multistory you may we’ll find the installation is three phase so there’s s very good chance the circuits may not be on the same phase.

Powerlines don’t need to be on the same circuit to work but they do need to be in the same phase.

I think all the communal area electrics are on their own meter and consumer unit, but I'm not absolutely sure. Hence, the need to test.

I have Powerline Adapters at home, and use them across circuits (upstairs ring main crossing to downstairs). However, I do appreciate that trying to carry a broadband connection across separate consumer units is difficult, if not impossible due to phase changes.

The plan is... to use a wireless bridge to cross between consumer units, then use Powerline Adapters once I know I'm on (at least) the same consumer unit electrics.

 

[Spoon]

No. You can see this on a persons profile

Ok. Learn something new each day..

 

[OttoF]

As it’s multistory you may we’ll find the installation is three phase so there’s s very good chance the circuits may not be on the same phase.

Powerlines don’t need to be on the same circuit to work but they do need to be in the same phase.

Thanks for this. I previously read up on the limitations of PLAs across different phases. What you've said seems to confirm what I've read.

I use PLAs at home which cross-over downstairs ring mains and upstairs ring mains. However, I've also read that it's best practice to stay on the same breaker circuit (if possible), to assure the best network connection stability and speed.

My plan is... to create a standalone network in the communal area. Once I've done this, then create a wireless bridge between one of the properties (that already has broadband and WiFi router), to join with the new communal area network.

The idea of the wireless bridge is to avoid any issues with PLAs trying to cross phases, etc.

I've have spare wireless routers and PLAs left over from previous projects, so it's the most cost-effective solution... as well as being a lot less hassle than running hundreds of meters of ethernet cable.