I wish for wifi access

What location do you think I put them in? I’m not daft. They’re on the consumer side of RCDs, so any significant fault current will trip the RCDs. All safe.

Plus the fact that the capacitor is supposed to be bridging higher frequency signals that would be filtered/muted by the RCD, so putting them on the other side would be pointless ?

so putting them on the other side would be pointless

Very probably, but as Nemo pointed out further upthread, RCDs (actually, iirc he only mentioned MCBs, but the same applies) vary – some are beautifully transparent to high frequencies, others are definitely not.

so any significant fault current will trip the RCDs. All safe.

I wonder – has anybody ever tested their RCDs?

As for radio interference, it is a thing and in some cases OFCOM can be involved to get the nuisance unplugged.

This site explains a little more… https://www.ban-plt.org.uk/ …though I think the author needs to calm down. Most interference is not deliberate as I would imagine for most people the things are “plug this in here, plug that in there, magic happens”, so those sorts of accusations are unhelpful in the extreme.
It’s a real problem, certainly, but one shouldn’t assume it’s being done on purpose until it’s known whether or not the neighbour with the thing is even aware that this is happening.

has anybody ever tested their RCDs

Yes, my oven does. Thanks very much, oven.

It tests them when you switch the upper grill off. And it tests them regularly when one of the elements blows, which has happened three times now.

It’s a fancy Fisher & Paykel which looks as expensive at the front as it cost. But once you open it – and you have to to change any element… brilliant – then you realise the inside is very cheap indeed. The elements have lasted three years on average. And I’ve now found they’ve discontinued one of them.

Buy anything else.

has anybody ever tested their RCDs

Yes, generally unintentionally, but deliberately on acquisition of a new property, always.

Of course radio interference is a thing, but it’s either a fault or a noncompliant device – either the transmitting or receiving device. Long ago I made an amplifier that turned out to be a transmitting device way above allowed limits*; and on another occasion I made another one that picked up police messages if their car was anywhere near. Both (unintentionally) noncompliant devices. But if you purchase a device, it ought to be compliant. Of course sometimes they aren’t, especially if they’re dodgy imports.

* I think I may have told this story here before, in rather more detail.

I live in America and I have TP-link range extender. It has an ethernet port on the bottom. Could use an ethernet cable connected from my Risc os pi 4 b to get internet. I hope I am being clear,rather new to all this. Thanks to all.

t’s a fancy Fisher & Paykel which looks as expensive at the front as it cost. But once you open it – and you have to to change any element… brilliant – then you realise the inside is very cheap indeed.

Sounds like the medical kit of theirs I recall working on in the 1980’s – expensive sh**e¹ but the people making the purchasing decisions frequently go for bells and whistles rather than plain function and reliability.

¹ Of course I could say that about a lot of stuff that gets the FDA stamp and floats across the pond – shame it don’t sink in most cases. Not that the euro-bods have a spotless record.

This site explains a little more… https://www.ban-plt.org.uk/ …though I think the author needs to calm down. Most interference is not deliberate as I would imagine for most people the things are “plug this in here, plug that in there, magic happens”, so those sorts of accusations are unhelpful in the extreme.

Well, in the opening line they list a collection of known offenders in the RF spectrum. Any user of licenced site radio tech will have experienced the local cab firms using badly maintained transmitters and interfering with multiple channels.
It’s a bit better when the site radio kit is digital, but there’s still carrier swamping on some channels at times.

and

“The recordings above were made with a standard portable battery powered AM radio tuned to various shortwave frequencies”

Quality test kit then. Makes nemo’s oven look like precision engineering, no doubt. The last time I was in a location using PLT (a holiday cottage) there was an AM radio plugged in to the socket next to one of the PLT units. The radio worked fine, you just had to make sure the radio was off or a distance away from the PLT unit or there were problems with getting a decent connection.

then you realise the inside is very cheap indeed.

We have a big complicated dish washer gizmo at work. To give you an idea, when it’s running full pelt, it can draw about 130kW.
It frequently “has issues”, though it’s throwing fewer tantrums now it’s had a few years to settle in (and the maintenance guys changing loads of bits)…Theseus’ dish washer.
One told me once, it was €60,000 worth of kit in a €600,000 box.

Yes, generally unintentionally

Yup. Me too. The last time was when I was fiddling with a power supply from a laser printer and didn’t realise the thing was plugged in. The stupid little plug carrying the mains input touched the metal rack the thing was screwed on to, sudden darkness.

Mom: Riiiiiiick!
Me: I think I saw a flash outside, is there a thunderstorm?
Mom: Haven’t heard any crackling in the radio.
Me: Okay, I’ll turn stuff back on, let me know if you hear anything.
😅

She listened to Radio 4 LW and everything interfered with it. My god, long wave sucks for interference.

Not that the euro-bods have a spotless record.

True, but with the new annoying import tax nonsense, nobody is going to want to purchase anything from “over there” any more…

The radio worked fine

Probably depends on the frequency. Mom used to tell me the exact time the smart meter was blasting it’s data down the line. I did wonder if I could decode it by recording the racket she heard and examining the sound sample, but never went anywhere with that idea.

Yes, generally unintentionally

My favourite trick – I never seem to learn – is (1) Turn off circuit A to work on it, leaving circuit B on (2) Snip a cable on circuit A.

Clunk. Circuit B cuts out.

D’uh. Circuits A and B share an RCD, but have their own MCBs. When I turned circuit A off, that disconnected the live. It didn’t disconnect the neutral, much less the earth. The snippers connected earth to neutral, allowing part of circuit B’s return current to disappear down the earth instead of the neutral.

This isn’t actually a very good test. Really you ought to test with a fairly high value resistor, not a nearly dead short to earth. Maybe it’s taking more than the regulation however many mA residual for however many ms to drop the circuit.

What location do you think I put them in? I’m not daft.

Oh, right? You see, upthread, someone called Clive said

a small HT capacitor between the phases at the meter

which I took (unreasonably, I know) to mean “at the meter”.

They’re on the consumer side of RCDs,

You mean “at the consumer unit”, then?

so any significant fault current will trip the RCDs.

It will? Phase to phase current will trip the RCDs?

Phase to phase, even after the MCBs or RCBOs in the consumer unit, will still need some fairly spangly capacitors of fairly specialised ratings – and high voltage ones at that, too.

You mean “at the consumer unit”, then?

Yes. Correction accepted. Everywhere I’ve lived, the meter and consumer unit have been right next to each other. Indeed when we connected our network to our neighbours, the connection wasn’t even at the consumer unit (that suggestion was to connect two rings in the same property, which in Rick’s case apparently could be on different phases – something I’ve never encountered in a domestic property) it was between two sheds in neighbouring gardens.

It will? Phase to phase current will trip the RCDs?

Yes. Very definitely. It means the current in the neutral lines through the RCDs won’t be equal to the current in the live lines through the RCDs, which is what trips them. RCD – Residual Current Device, that is, the difference between the outgoing and returning current.

and high voltage ones at that, too.

Indeed, as I said. Phase to phase voltage is around 430V. It’s no problem getting suitable capacitors (1kV or more for pennies), although with the departure of valve amps and CRTs from the scene they are getting less common, it’s true. While the voltage requirement is big, the actual capacitance values are tiny, so they’re not physically big beasties. (The capacitance value has to be tiny, or the RCDs will trip – and you don’t need more than a tiny value to be transparent to your high frequency signal.)

Oh, if anyone was daft enough to try to connect a capacitor (or anything else) between the phases the wrong side of RCDs, any significant fault current would be a purely local problem – a bit of a bang in the meter cupboard as the capacitor destroys itself. A short circuit through a small component won’t draw enough current do anything to the cables connecting the house to the mains, or even blow your main fuse. And surely no-one would think of trying to connect anything the wrong side of the main fuse(s if you’ve got two or more phases on the property)? Not that it would make any difference if you did: these components, even in fault conditions, won’t cause that big a short. But you can’t get at anything the wrong side of the meter without snipping the electricity board’s seals, which is a bit of a hint…

But working on anything the wrong side of RCDs risks you getting a mains (or even worse, phase-to-phase, if you’ve got more than one) electric shock, since you can’t turn it off. DON’T DO IT, FOLKS.

And surely no-one would think of trying to connect anything the wrong side of the main fuse

Surely it ought to be possibly obvious that there’s no way to turn it off?
If not, it’ll be fatally obvious in short order.

That being said, can one even legitimately get at any of the wiring before the meter? On my setup all that stuff is closed with locking green ties that will snap if messed with. Otherwise, one could start hooking stuff up before the meter…

If not, it’ll be fatally obvious in short order.

Not necessarily, although I grant you it’d be a bloody stupid risk to take. It’s 240V (or 430V), someone could, if they were daft enough, work with insulated tools and a great deal of care.

That being said, can one even legitimately get at any of the wiring before the meter?

No, not legitimately. Nor sensibly.

On my setup all that stuff is closed with locking green ties that will snap if messed with.

Similar in the UK, as I wrote, “without snipping the electricity board’s seals, which is a bit of a hint…” (although they’re as much concerned with protecting their profits as protecting their customers…)

Very definitely. It means the current in the neutral lines through the RCDs won’t be equal to the current in the live lines through the RCDs, which is what trips them. RCD – Residual Current Device, that is, the difference between the outgoing and returning current.

Yes, but I think you’re making some assumptions about the configuration of the loads on those RCDs? Phase-to-phase current is perfectly reasonable (and expected) in some arrangements, and the RCD will sum the phases and neutral and compare to zero (just as a single-phase RCD will sum line and neutral).

Phase to phase voltage is around 430V. It’s no problem getting suitable capacitors (1kV or more for pennies), although with the departure of valve amps and CRTs from the scene they are getting less common, it’s true.

Not sure why you mention valve amps. It’s a line to line application, so I suspect that you’re looking at X1 or Y class capacitors (maybe X2, but the location would make me want to do some careful checks on the standards), which would be unlikely to be used in an amp unless they were also in a line to line or line to earth location.

The capacitance value has to be tiny, or the RCDs will trip

Yes, in fact you’ll probably find that there’s a standard for how small it must be. There’s definitely one for line to earth in the places that I’ve put Y-caps over the years, for exactly the same reason; I’ve never really felt the urge to fit one cross-phase at a consumer unit.

Oh, if anyone was daft enough to try to connect a capacitor (or anything else) between the phases the wrong side of RCDs, any significant fault current would be a purely local problem – a bit of a bang in the meter cupboard as the capacitor destroys itself. A short circuit through a small component won’t draw enough current do anything to the cables connecting the house to the mains, or even blow your main fuse.

I wouldn’t be so sure. If it manages to get an arc going before it vaporises, all bets are probably off.

I’ve worked with people who actually know what they’re doing in this area, and even down-stream of the main fuses and meter it’s all arc-proof suits, gloves and visors… and someone else a safe distance away on the other end of a rope that’s tied around your waist to give a good tug if it really does all go wrong.

I know there’s a time and place for irrelevant culture, but it’s impossible not to share Laurie Anderson’s Dance of Electricity at this point.

I think you’re making some assumptions about the configuration of the loads on those RCDs? Phase-to-phase current is perfectly reasonable (and expected) in some arrangements

Indeed I am. A three-phase RCD will indeed behave as you say. I’m assuming separate single phase RCDs on the two phases I’m bridging between. I can’t imagine wanting to use a three-phase supply for Powerline adapters, and if it’s two ring mains on different phases they surely won’t be using a three-phase RCD.

Yes, in fact you’ll probably find that there’s a standard for how small it must be.

Doubtless, but there’s loads of leeway between a fairly big capacitor that will pass enough 50Hz to trip an RCD, and the tiny capacitor that’s all you need to pass an ethernet signal.

If it manages to get an arc going before it vaporises, all bets are probably off.

That’s a pretty big IF, but your point does stand. But as I say, it’s not something anyone in their right minds would be trying to do anyway.

Not sure why you mention valve amps.

Because they’re liable to use voltages way in excess of 430V between anode and cathode. EL34s could be using 800V.

Can’t help but feel this topic should be renamed “try this at home”.

Or, much better still …
Don’t try this at home – or anywhere else.

and all because the OP has his isp router in another room

Simpler to put everything in one room and we can all move on:)

Can’t help but feel this topic should be renamed “try this at home”.

If you know about putting the old-fashioned red cap match heads between two bolts screwed into one nut and dropping the bolt(s) head on onto a stone or paving slab and hear the nice bang.
Concoct a better explosive¹ use coach bolts and then maze yourself by blowing one of the two bolts through an overhanging oak tree branch of approx 6 inch diameter.
Then contemplate how big a hole it could make in you and decide that maybe it isn’t good to repeat.²

No? Maybe that’s another don’t try this at home.

A part of me says running an extension from each phase and putting a barely capable capacitor on a switched link between the two, out in the open might be interesting.
My childhood is clearly not as far away as it ought to be.

¹ It helps if you have an unusual library at home and an enquiring mind.

You both missed the implied isn’t.

If one says Don’t do this at home, somebody might think about it, or even consider it an idea of where to buying a random capacitor to get power line networking working.

But do do this? Meh, nah…

A part of me says running an extension from each phase and putting a barely capable capacitor on a switched link between the two, out in the open might be interesting.

If I was wanting to do this – get powerline signals between two different phases – I would be looking at using a small ferrite transformer (for high bandwidth) with each winding fed from one of the phases through a small capacitor. Just maks sure that the transformer had a breakdown rating between the windings of at least 400 volts, and the capacitors 240 volt rated.

Long ago I made an amplifier that turned out to be a transmitting device way above allowed limits

When I was at Uni in the 1960’s Sinclair produced an amplifier kit that used pulse-width modulation. One of the students bought and built one.

While it worked, the switching frequency was 100kHz, and radio 2 at the time was on 200kHz. As a result nobody in Bangor could receive radio 2 while the amp was operating.