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Comment by elzbardico | Hacker News Reader

How can folks not see that using such contraption is obviously a shitty idea?

That’s why we need to completely overhaul the teaching of physics in middle and high school.

Every citizen should have at least a basic understanding of basic physical concepts that allow then to understand why this kind of thing is a bad idea

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So, I have a very good understanding of basic physics. I have a very good ability to critically think. I am, what I would consider, educated and intelligent.

And there was a time in my life when I googled "double male cord" because my snow-blower has a female plug for the electric start that is supposed to go to a converter box specifically sold by the company, and I lost it and didn't want to pay $100 for a new one.

Had I not paused and thought twice, I absolutely could've purchased one without thinking, or made one myself.

I guess what I'm trying to get at is, people can be stupid, even if they're smart.

I think that just underlines his point though, you started going down that path and then had the ability pause and think critically for a moment.

Had the knowledge too though. Many people lack the knowledge of how things work, as well as the inclination to stop and think before acting.

Sometimes even smart people might forget to pause.

Whoever green lit the decision to use a female NEMA plug plus a specific converter box should be banned from product design. It would have probably been fractional cents more expensive to use a male plug on the snow blower.

If you plugged your double cord into the snowblower and never unplugged it, it wouldn't be that unsafe.

Electricity is like magic to most people. If you ask around you'll find that folks don't have the vaguest idea how it works. All they know is "plug it in and it turns on". These people are eating and sleeping inches from voltages that could easily kill them. Safety measures are fairly good (even with the terrible US plugs), but safety devices can only go so far.

I would strongly encourage that everyone (even those who aren't interested in technical subjects) learn the water analogy and some electrical safety fundamentals.

You don't have to know all the physics, but you should be given a basic intuition of what current, voltage, resistance, and power are.

There's a fun little book called "There Are No Electrons" the premise of which is that most early education on electricity is full of bullshit analogies, but that those are also misleading and confusing, so it basically sets out to present a different set of incorrect-but-useful analogies that're easier to understand and are good-enough to give you decent intuition for how electricity works—even if it's "well ackshually" entirely wrong.

Water analogues kinda assumes you somehow know hydraulics but not electrics tho.

I've used fluid analogies for intuition, even working as a professional design engineer. It's much easier to feel flow, pressure, momentum, etc than try to develop an independent intuition based solely on equations.

I'm actually starting to learn hydraulics at the moment and it's a head trip. I know these schematic symbols must have some kind of method to them, but what. Also all of these components are just created by drilling holes in metal blocks? One simple trick manufacturers don't want you to know.

Yeah but it's only similar from a very far away. Like just simple resistor, in electronics flow increases linearly with voltage, in hydraulics it doesn't.

Or how in some hydraulics system it's not really the flow that's the motivator for action, like in simple hydraulic brakes it's not the flow of the fluid in a circle that powers anything, it's just that the push on fluid on one side pushes the brake pad on the other. So it's not really a flow but wave of pressure (which is kinda how current actually flows in the conductor anyway...)

> simple resistor, in electronics flow increases linearly with voltage, in hydraulics it doesn't

Sure. I'm not advocating substituting electronics components with a similar seeming hydraulic one and then taking it literally, but rather guiding your basic intuition. The linear resistor is actually much nicer than the nonlinear orifice when it comes time to calculate. And some times the fluid model even does a better job encouraging one to pay attention to things like parasitics, which are too easy to ignore when looking at a circuit diagram without them.

> in some hydraulics system it's not really the flow that's the motivator for action, ... it's just that the push on fluid on one side pushes the brake pad on the other

Like the gate of a common FET.

People can't see it's a shitty idea because they're operating at the level of clicking on Amazon and assuming it wouldn't be sold if it weren't safe. This shouldn't be a CPSC warning, but rather a prosecution.

I myself have made a suicide cable to move a load from one circuit to another without shutting it off. But doing the wiring myself made it very clear that I was off the beaten path, and so I had to really think through what I was doing. There's a few obvious concerns with the use I've described here, but I'm not going to write them out because they should be either readily apparent, or you should not be doing such things.

It's the same territory as working with line voltage on a test bench, floating an oscilloscope, etc. All things that can be done safely when you're knowledgeable and focused on the task at hand. But should never be normalized into every day relaxed life, even if you "know what you are doing".

When I was a small child with endless un-jaded curiosity and no fear I once took a pair of cutters to a power cable plugged into a live 120v US outlet; it made an incredibly bright arc that I could see the afterimage of in my vision for several minutes and a deafeningly loud pop (In retrospect may have been the first stage of my tinnitus). For years growing up I would look at the replacement power cable for that electric typewriter and always feel pretty dumb.

Obviously nobody should learn that way and I'm thankful to not be dead or otherwise, but I was kind of disappointed growing up that in school I was never taught why this was a bad idea, even when I asked all I got was a wide eyed stare and a stern 'never do that again', never a 'So that's a bad idea and here's why..' Maybe in an alternative life I'd have become an electrician? Who knows.

For a very few milliseconds you were an electrician - they don’t call them Sparky for nothing, after all.

I wish they'd just do quick, practical examples.

This is what happens when you mess with mains voltage and chuck a fork into a circuit. Maybe even a dead rat/frog. This is what happens when you put too much power into a wire, and let them watch it catch on fire.

I knew power was conceptually dangerous when I was a kid. I didn't realize how dangerous until I tried to change a light switch as a teenager, and didn't realize the house had multiple breaker boxes. Watching fairly thick copper wires melt themselves scared the hell out of me.

I won't do anything over 12v myself to this day. I'm too hasty and easily distracted for it to end well.

People make mistakes. I might have done something like that until reading the article. This caught my eye,

> the flow of electric power in the direction reverse to that of the typical flow of power circumvents safety features of the home’s electrical system and can result in a fire.

At first I thought they were BSing. A fuse doesn’t care which side is the source, it blows on current. I kept thinking about it and realized what they’re talking about. If you plug a 30a generator circuit into a 15a circuit and then draw more than 15a on that circuit (thereby avoiding the fuse/CB), you’re going to have a bad time. Similarly, even if you’re only drawing 15a on that circuit, but you draw another 15a on another (15a bypassing the fuse and 15a going thru the fuse), you’re still going to have a bad time.

It’s a very specific set of circumstances, but it probably happens more than you would think. Because of the fact that they’re only energizing half their circuits, they probably start moving loads to working outlets.

One look at the image and my immediate reaction is "no way anyone would be stupid enough to buy something like this"

It's like an utterly evil version of that "HDMI to Gardena" meme, only it actually exists and Amazon carries it...

https://external-preview.redd.it/AOlxnd9E3WMW3KID3LhjpL3o70s...

My undergrad was electrical engineering. I work as an engineer. I'm not inclined to buy one of these (and not just because I could simply make one if I wanted).

One look at that image, and the reaction of a lot of people would be "they wouldn't sell it if it weren't safe".

Should the nanny state prevent the sale of such things? Well, ignoring that the nanny state disallows the sale of things like cannabis in many locations, I argue that people who are smarter than average can make things that the person of average intelligence is likely to unsafely use. We can post all of the dismissive comments we like, but a lot of people are $SOMETHING_OTHER_THAN_ELECTRICIAN_OR_PHYSICIST. If you look at that item and your reaction is "unsafe", well, good for you and thank your preferred deity for the privilege you've been given. Now see if you can spare a thought for those to whom it is not obvious. You've got your blindspots, too, but it doesn't necessarily make you stupid.

I mean most people know it's a terrible idea, it's just that 0.1% of a population of 330 million people is 330k people, and I don't think that 0.1% is from a failure of our education system

Why would you think that most people would just know it’s a terrible idea? After all, the vast majority of (digital) cables that people use mostly work just fine so long as they fit—leaving aside vagaries of USB-C and Thunderbolt.

> Why would you think that most people would just know it’s a terrible idea?

I dunno, statistic about deaths from electrocution?

And why would they connect overall statistics about deaths from electrocution to that particular thing? Lots of ways to get electrocuted.

Sure but they're pretty much overall, so adding "coz he used a suicide power cord" would show even less people actually affected"

The problem isn't that it won't work, it's the exposed live prongs.

Your estimate could be extremely high. What those quick with a dismissive comment forget is that 15% of the population has an IQ of 85 or less. So to answer the FAANG-employed Stanford grad's question of "how could anyone be this stupid?": easy, a non-trivial percentage of them are born that way.

Regardless, there are plenty of my Microsoft/Google/FB-employed neighbors that I wouldn't trust around anything more dangerous than what comes out of a USB port, either.

The fact it got taught in school is only lightly correlated to what adult will know. It's also indirect, like, math teaches you everything you need to know to calculate load or do your taxes, or home budget, yet people have problems with it coz they never had someone teach them how to apply knowledge to real problems

As a layperson, electricity is one of those things that seems really complex and dangerous to mess with. But we've managed to abstract it down to "plug this cable into a socket" or "flip a switch". I remember doing the V = IR calculations in highschool, the difference between alternating and direct currents, as well as the relationship between volts and amperes.

While fascinating, none of that translated to real world working knowledge. In fact I was greatly surprised to learn about how my outlets are actually wired when I had to get my home's electrical panel replaced. Turns out, swapping electrical outlets and switches is actually really easy, but I only felt confidence once I had an electrician show me. Otherwise I would still be too worried about burning my house down

We spent hours calculating the impedance and current and resistance and whatever in dozens of complicated circuits in undergrad, and I can't tell you how a basic home electrical installation works. File that under "things that everybody should know but school doesn't want to teach".

It's not just knowing how to do it, it's actually doing it right that counts. That's something nobody can guarantee, but experience (and professional insurance) can help with.

Just try and find those male-male cords for other outlets than US ones (try Schuko for the European variant). You will find that they're much more rare or even impossible to find.

Realizing that these cables basically exist only in one variant, which is for US style outlets, should tell you a lot ;-)

It probably tells us that the power grid is more reliable in Europe (less rural areas etc). Very few people own a generator.

Probably because the alternative is to not have power during the (increasingly common) blackouts.

I'm assuming that is the alternative due to there not being a proper way to accomplish this goal that does not cost thousands of dollars.

There are reasonably priced (under $100, though not under $3 like a common receptacle) male power inlets.

https://www.homedepot.com/p/Reliance-Controls-30-Amp-Power-I... is the first one I found on Google (4-wire for 240V center-tapped), but there are many, including a 120V version: https://www.amazon.com/Leviton-5278-CWP-Straight-Flanged-Rec...

Even these, if hardwired to the building's service, represent some risk, but the risk is to the people poking fingers into the box, which could reasonably have a locking cover on it. If that male inlet is powered only via a transfer switch or a back-fed breaker that's normally off, the risk is much, much lower than a double-male cord.

Unless it is installed properly, that is just as dangerous as the cord in the article, as long as you remember the "plug generator in last" rule.

In particular, both can kill hapless power company employees by unexpectedly backfeeding into downed parts of the grid, and they have similar carbon monoxide/fire hazard issues.

(Not that there is anything wrong with the product; I wish they were mandatory, so they'd reliably be inspected after installation!)

I don't know what percentage of electrical work is inspected, but I would certainly not characterize it as "reliably". There are aisles full of electrical equipment sold at Home Depot and Lowes. The (vast?) majority of that is getting installed with no inspections.

Inspections are hard to avoid when you build a new house, or perform major renovations.

If the outlet were required at that point in time, there wouldn't be a temptation to improperly retrofit the outlet in later.

Most building codes (as adopted by the AHJs) do not require systems not part of the job to be brought up to current code if they met code at the time of install, are in good repair, and are not being significantly worked on. You can add an addition without converting all the old bedroom breakers to AFCI. (That represents a much higher safety risk than any generator inlet could possibly be.)

Well yeah, but if the addition (or your new EV, which might actually support working as a home backup battery) requires a new panel, then the port would be required.

On the other hand, generators are rapidly becoming obsolete, so this might be akin to requiring installation of upgraded coal shoots.

My local code allows me to replace outlets without any permit/inspection. With toddlers around I've replaced a lot of outlets with modern safety outlets (have a shutter so you can't stick something in the hot slot).

I've done other electric work that has passed inspection.

The actual chance of your generator backfeeding the grid is nigh nill. The issue is that all your neighbors are still connected. The moment your generator touches the grid it acts as pretty much a dead short.

Not saying it can't happen. The main one where it could is if the break is between your house and everybody else. But in the vast majority of situations you will instantly pop the dinky 15a breaker

The correct low-budget way to connect one of these is using an interlock kit:

https://www.se.com/us/en/product/HOMCGK2C/load-center-access...

You need the inlet, the kit, and a correctly sized breaker that is suitable for backfeeding.

Yes!

Not only is a mechanical interlock a code-compliant method to properly protect downstream line workers but it is also a simple and comprehensible component that costs very little and never breaks.

We have a whole-house generator connected to our main panel and I made a very deliberate decision not to add the complexity and fragility of an automatic transfer switch. The little metal tab will always work and nobody will ever be confused.

I highly doubt that having an electrician come out to install an outdoor inlet would cost thousands of dollars.

It definitely would be thousands to get one of these installed in California. The electricians cost way over $100 per hour.

Also, a backflow cutoff is required by law, as are permits, inspections, etc.

San Jose has setback requirements, requires a concrete pad (for hardwired installations), and charges various fees:

https://www.sanjoseca.gov/home/showpublisheddocument?id=4499...

It wouldn't surprise me if you could get a deal on "new generator; free installation" though.

The parts alone to do it properly are several hundred dollars - the inlet box is around $60, 25 feet of 10/3 cable is $100 (obviously more for longer - wiring has gotten really expensive the past few years), circuit breaker $20, interlock kit is $150 (https://interlockkit.com/product/square-d-kit-k-5010-125-200...). Plus permit and inspection ($150 is the cheapest permit in my town). That's already $480 and you haven't even talked to the electrician yet.

If you get lucky and find an inexpensive electrician AND the inlet you want to install is located very close to the panel (minimal drilling, short wire, etc.), you can probably get it done for less than $1000, but probably not a whole lot less.

Installing an outlet yourself? Buy one for $10 or something, more if it's some special outlet, maybe spend an hour or two at most with the actual install.

Hire an electrician to install it for you? Between markups and labor, easily several hundred bucks at the very least. A thousand is entirely plausible.

Ignorance is expensive, knowing how things like electricity and plumbing work will save you money and help make life more fulfilling.

My city charges $300 just to pull a permit, and an electrician charges $100 just to show up. Then at minimum you'll need a new branch circuit, breaker, conduit, fittings, outdoor box, wire, interlock kit, and the outlet. And you better hope your breaker box has availability for a new branch and that it's recent enough for an interlock kit. If not, you'll need to replace the entire panel and all circuit breakers. And in my jurisdiction, grounding requirements had recently changed, and my local inspector required that I bring the grounding up to code in order to have any work approved.

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