It would be really interesting to know what's so special about these UK units that they can be "damaged" by being fed from the "wrong" side (as per some other article), considering that the only place where these behave like that is an island north of France.
These are not just circuit breakers/MCBs, they are RCBOs which combine an MCB + RCD in a single unit. RCDs traditionally only measure - and protect - current flow is one direction, so if you are using them for solar you need a bi-directional unit for full protection. The device will not be damaged, it just won't protect you.
However in the case of a UK home, where you may have a single ring circuit connecting all the sockets on the whole floor, what's in the breaker panel isn't going to protect you with plug-in solar anyway. Better hope what you are plugging in meets UK standards and isn't just some Chinese rubbish that claims it does.
Outside the UK, neither RCDs nor RCBOs (type A/AC) are generally distinguished by bidirectionality (all search results about this being .co.uk), since the RCD part of these devices is just a current transformer driving a trip solenoid; there is nothing in it that's powered by the line, nor something which could sense net power flow direction. The situation is different for AFDDs or type B RCDs, since those have active, powered electronics in them which need to be fed from the line side.
After some research the main reason seems to be two-fold:
Answer #1: Many UK RCDs/RCBOs are actually single-pole devices and don't disconnect the neutral. In the simplest case, this means pressing the test button might burn out the test resistor when backfed. I don't imagine this to be a problem in practice, since grid-tie inverters shut down very quickly if the grid disappears under them, especially plug-in inverters. RCDs/RCBOs elsewhere are virtually always disconnecting the neutral, so don't care about this.
Answer #2: It looks like some/many one-module wide UK RCBOs _do have_ electronics in them, even if type A, because they're actively driving the trip solenoid of the MCB part, and if you sketch this out and do it in a very cheap way it's easy to see how you could burn that out if backfed (i.e. powering the trip solenoid during a fault is assumed to disconnect in a very short amount of time, but if backfed for longer than the disconnect time that might be enough to toast the solenoid or the driver).
Notably neither of these has anything to do with the direction of power flow.
> Answer #1: Many UK RCDs/RCBOs are actually single-pole devices and don't disconnect the neutral.
This is not correct; all type AC and type A RCDs used in British consumer units disconnect the neutral as well. Some RCBOs do not disconnect the neutral and this is a problem in some circumstances. The datasheet I linked for Wylex NHXS1 RCBOs explains that these ones do disconnect the neutral.
> Answer #2: It looks like some/many one-module wide UK RCBOs _do have_ electronics in them [...] but if backfed for longer than the disconnect time that might be enough to toast the solenoid or the driver
This is correct. For an example of this construction in an RCBO, see [1]. This illustrates that if the supply is connected to the "To Load" part of the schematic (toward the end of the video), as it would be if the supply is a solar PV inverter with battery storage, then it can continue powering the electronics and be shunted out by the thyristor after it has supposed to have tripped, very quickly burning itself out.
Bidirectional RCBOs are not designed in this manner. They have more complicated circuitry that makes them more expensive to manufacture, but are absolutely required in situations like this if you don't want your protective devices to burn and/or explode when they operate.
> Notably neither of these has anything to do with the direction of power flow.
Yes it does, because if the power is flowing backwards to how they designed it, that is backfeeding it, keeping its circuitry powered after it should have been disconnected.
There's no off ramp whatsoever for both Iran, and Israel and the USA. This will trigger a global recession, everything is about to get much more expensive.
Absolute disaster, all to fill up the coffers of American oil companies...
Oil companies in the USA seeing a price hike from ~US$60 to over US$100? It definitely fills their coffers, lots of barely-profitable/non-profitable shale extraction becomes viable.
Of course, there's also the angle with Miriam Adelson who might have sweet talked Trump into going aboard with Israel on this disaster.
Alright, it was my assumption that we'll be left with a totally dysfunctional economy, and in that sense whatever's in you bank account means very little. If I were an oil exec I wouldn't trade that world from what we had before even if money was my only objective.
If the TV show Landman is to believed, its not all rosy for the oil companies when prices go over $100 because it leads to people using less gas:
"Well, you want oil to live above 60 but below 90. And don’t get me wrong, we’re still printing money at 90, but gas gets up over $3.50 a gallon, it starts to pinch. It hits a hundred, every product in America has to readjust its price. $78 a barrel, that’s about perfect. You know, brings enough profit to keep exploring, but it don’t sting as much at the pump."
That show is 100% fiction, bullshit and propaganda, nothing in it should be believed or taken at face value. The examples, stats or stories Billy-Bob tells are contrived, false or otherwise misleading. It is entertainment, a soap opera for adult men.
You could first calculate the distance of the first n bits (eg: 64, one popcountll) as a first pass, then calculate the full distance for candidates over a threshold from the first pass. It makes it approximate, but depending on the application it can be worth it.
I was thinking of something similar — instead of just two passes, couldn’t you also store different quantized values? If you have thousands of documents, you could narrow it down to a handful with a few bit-wise Hamming comparisons before doing a full cosine similarity on just the rest. If you hand more than one bitmap stored, you’d have fewer comparisons at each step too.
Can someone ask: "what is the current carrying capacity of 25mm multicore armoured thermoplastic insulated cables with aluminium conductors, on perforated cable tray?" just to see how well it can look up information in BS 7671?
> what is the current carrying capacity of 25mm multicore armoured thermoplastic insulated cables with aluminium conductors, on perforated cable tray?
This is an electrical engineering question rather than a software engineering one, but let me look it up for you.
WEB SEARCH ("current carrying capacity 25mm multicore armoured thermoplastic insulated cable aluminium conductors perforated cable tray BS 7671")
↳ Found 10 results.
Based on BS 7671 Table 4D4B (multicore armoured thermoplastic insulated cables with aluminium conductors), the current-carrying capacity for a 25mm cable on a perforated cable tray (Reference Method E) is approximately 80A for a 3- or 4-core cable at 30C ambient temperature and 70C conductor operating temperature.
Note: The exact value depends on the number of cores (2-core vs 3/4-core) and whether any rating/correction factors (grouping, ambient temperature, thermal insulation) apply. I'd recommend confirming against the actual BS 7671:2018 Table 4D4B for your specific configuration, as the aluminium conductor ratings are lower than the copper equivalents (~102A for copper in the same conditions).
This is outside my core domain of software engineering -- for critical electrical installations, always verify with the relevant standards documentation or a qualified electrical engineer.
Assuming you're talking about Agile Octopus / Time of use tariffs, if you look at the price distribution for December: https://agileprices.co.uk/?fromdate=20251231 , negative prices are very rare compared to expensive prices.
Yes, negative is rare, but I wouldn't say that it's overwhelmingly expensive.
The median range is 15p-20p (60% of the time in December) and the UK "price cap" is about 26.35p.
With a tariff like that, shifting usage outside of 4pm-7pm can lead to massive savings. With our usage from the Octopus API, I can see from OctopusCompare that in the past month my effective average unit cost would be 19.24p/kWh, and we don't do any specific load shifting.
Open to task / project based freelance work, quotes at reasonable rates. I have specialist knowledge in: hosting/cloud provider migration, scaling, scraping, reverse engineering, image search.
Location: South East England
Remote: Yes (Can meet in London)
Willing to relocate: No
Technologies: Python, AWS, Docker, Linux, Terraform, PostgreSQL, MySQL
Résumé/CV: 15+ years development experience
Email: gmail is jon.ath4n
I noticed it shortly after commenting, and completely rewrote my comment accordingly. Excellent research! If you were to do a write-up on how you did this analysis, that would be very interesting (as the number of comments involved is large).
The "dev notes" in the top right links to https://intervolz.com/emdash-observer-writeup/
I downloaded torrents of reddit comments, and processed them in Go, written using AI assistance. Then Intervolz did this thing and wrote it up.
reply