[tcdent]

I can't believe a group of engineers are so afraid of residential power.

It is not expensive, nor is it highly technical. It's not like we're factoring in latency and crosstalk...

Read a quick howto, cruise into Home Depot and grab some legos off the shelf. Far easier to figure out than executing "hello world" without domain expertise.

[gizmo686]

A good engineer knows the difference between safe and dangerous. Setting up an AI computer is safe. Maybe you trip a circut. Maybe you interfere with something else running on your hobby computer. But nothing bad can really happen.

Residential electrical is dangerous. Maybe you electrocute yourself. Maybe you cause a fire 5 years down the line. Maybe you cause a fire for the next owner because you didn't know to protect the wire with a metal plate so they drill into it.

Having said that, 2 4090s will run you aroud $5,000, not counting any of the surrounding system. At that cost point, hireing an electritian would not be that big of an expense relativly speaking.

Also, if you are at the point where you need to add a circut for power, you might need to seriously consider cooling, which could potentially be another side quest.

[XMasterrrr]

I agree with you on all of that. I went down the rabbit hole to understand what's up, but I also hired someone and told them exactly what I wanted: breakers amps and volts, outlets type, surge protector over the entire breaker box up to 120k, etc (I am going to be writing about power and electricity in part 3 of this blogpost series). Electricity was on top of the things I was not going to cheap out on because the risk vs reward made no sense to me.

Re: cooling; I have an AC vent directed on the setup, plus planned out in-out in the most optimal way possible to maximize cooling. I have installed like 20 more fans since taking these pictures :D

[vunderba]

Just a slight clarification, an RTX 4090 card currently runs about $1700 USD at least in the states, so it's more like $3500 pre-tax.

[XMasterrrr]

A year ago it was a struggle to get one for anything below $2100 pre-tex. Glad it came down a bit.

[tjoff]

Add to that is that it is likely illegal to do yourself. Which of course has implications for insurance etc.

[m-s-y]

In the US, it’s fully legal to perform electric/plumbing/whatever work on your own home.

If you screw it up and need to file a claim, insurance can’t deny the claim based solely on the fact that you performed the work yourself, even if you’re not a certified electrician/plumber/whatever.

What you don't want to do is have an unlicensed friend work on your home, and vice versa. There are no legal protections, and the insurance companies absolutely will go after you/your friend for damages.

Edit: sorry this applies to owned property, not if you’re renting

[earleybird]

In my jurisdiction I can certainly do the work but am under the same requirements to pull a permit and pass a provincial inspection. It very quickly becomes the most effective to have an electrician involved, maybe not for all the work but some of it. They're more that willing to review the work you do and talk about it. Think of it as pair coding - great opportunity to learn and they'll tell you when you've done a good job. (at least the ones I've found)

[gizmo686]

Around here, the bar is lower for work on your own property, but you still need to be qualified by the county to be allowed to do so. Qualification consists of a 2 hour open book exam, where the book is a copy of the national electrical codes.

https://www.montgomerycountymd.gov/DPS/Process/combuild/home...

Granted, if you actually do unlicensed work in your house, no one will know. But it is still illegal.

[jefftk]

Depends on the state and municipality. Mine doesn't allow homeowners to pull electrical permits.

[scubbo]

Extraordinary claims require extraordinary evidence.

[zamadatix]

As with most regulations in the "US" I have a feeling the answer is really something like "Depending on the city and state you live in the answer lies somewhere between 'go nuts' and 'that could lead to criminal charges and you being liable for everything that happens to the house and your neighbors kitchen sink'".

[defrost]

It's like that in Australia, liability and insurance hinge on licenced work by trade qualified professionals.

What is common here, in the handy crowd at least, is to do your own electrical, plumbing, gas work and leave it open and accessable for a licenced professional to check and sign off on.

You're still paying for an hour or two of their time and a surcharge for "taking on the responsibility" but it's often not an issue if the work is clean, to current code, and sanity tests correct (correct wiring, correct angles on plumbing, pressure testing on gas pipes).

[tourmalinetaco]

It‘s hardly an extraordinary claim. Just because you can’t install a ceiling fan doesn’t mean it‘s an “extraordinary” feat that is “likely illegal”.

[scubbo]

> insurance can’t deny the claim based solely on the fact that you performed the work yourself

_This_ is the claim that is extraordinary. I'm not saying that the government would bust down my door for doing work on my own home, but rather that the insurance company would then view that work as uninsured.

The entire business model of insurance agencies is to find new, creative, and unexpected ways to deny claims. That is how they make their money. To claim that they would accept liability for a property that's had uninspected work done by an unlicensed, untrained, unregistered individual is just that - extraordinary.

[bigiain]

> Also, if you are at the point where you need to add a circut for power, you might need to seriously consider cooling, which could potentially be another side quest.

There should be an easy/reliable way to channel "waste heat" from something like this to your hot water system.

Actually, 4 or 5 kW continuous is a lot more than most domestic hot water services need. So in my usual manner of overcomplicating simple ideas, now I want to use the waste heat to run a boiler driving a steam engine, perhaps to directly mechanically run your air conditioning or heat pump compressor.

[raxxorraxor]

Instant water heaters use up to and sometimes even more than 27kW. Of course boilers use less, but still...

These aren't power requirements that are insurmountable. They would get pricey though and I wish my rig for computing would use something around .1kW under load...

Using the heat from PCs would be nice. I guess most just use them as electrical heaters right now.

[XMasterrrr]

Let me know if you figure it out, I would be really interested hahaha

[BizarroLand]

I'm doing this myself now. I have a homelab server setup and a hybrid water heater.

Stuffed the homelab next to the air intake of the water heater, now when I need hot water my water heater sucks the heat out of the air and puts it into the water.

It's obviously not 100% efficient, but at least it recaptures some of the waste heat and decreases my electrical bill somewhat.

[lolinder]

> I can't believe a group of engineers are so afraid of residential power. ... Read a quick howto, cruise into Home Depot and grab some legos off the shelf. Far easier to figure out than executing "hello world" without domain expertise.

The instinct to not touch something that you don't yet deeply understand is very much an engineer's instinct. Any engineer worthy of the title has often spent weeks carefully designing a system to take care of the hundreds of edge cases that weren't apparent at a quick glance. Once you've done that once (much less dozens of times) you have a healthy respect for the complexity that usually lurks below the surface, and you're loathe to confidently insert yourself confidently into an unfamiliar domain that has a whole engineering discipline dedicated to it. You understand that those engineers are employed full time for a reason.

The attitude you describe is one that's useful in a lot of cases and may even be correct for this particular application (though I'm personally leery of it), but if confidently injecting yourself into territory you don't know well is what being an "engineer" means to you, that's a sad commentary on the state of software engineering today.

[tcdent]

Sir, this is "Hacker News".

[lolinder]

So did you mean "I can't believe a group of hackers are so afraid of residential power"?

[3eb7988a1663]

People can and do die from misuses of electricity. Not a move-fast-and-break things kind of domain.

[varispeed]

You only "break" once...

[lbotos]

I've been learning Japanese and a favorite of mine is: 一体

Which is used as "what the heck" but it's direct kanji translation is one body.

https://jisho.org/word/%E4%B8%80%E4%BD%93

[varispeed]

Fun fact as a kid I stuck my fingers in the loose mains wires as we were playing at unfinished building. The wires were live and I still remember it felt like it's going to break my arm. Fortunately I only got a slight burn. This got me interested in electronics which I started studying later in my life.

[fhdsgbbcaA]

You’re forgetting many people have landlords who aren’t exactly keen on tenants doing diy electrical work.

[tourmalinetaco]

I’m hardly surprised, this is primarily a programming discussion website, and the highest voltage read on an average day here is in mV. It’s natural to be leery of things you have no experience in.

[fragmede]

your car is 12 volts, and USB is 5 volts; 12 or up to 20 these days for laptop charging. My computer's CPU is probably 1.8 volts but I can't remember the last time I had my multimeter on that, but that's still more than millivolts.

[raxxorraxor]

Probably meant milliampere, specifically 1 milliampere. But yes, usually lightweight engineers are familiar with TTL and limit themselves to 5V. 12V+ is another arcane realm you don't want to touch.

Some old serial ports had 12V and a high max current. The DIY things you attached here were prone to kill your mainboard.

Voltage/current is either 0 or 1. Anything higher kills software developers instantly.

[matt-p]

In telecoms 48V dc is very common and not always even connectorised! It's "safe-ish" but DC makes me more nervous than 240v, big thick 400A cables into a rack are quite intimidating to see but the main issue is DC is sticky and doesn't have the safety protections of RCDs etc. Indeed you are lucky to get a working isolator.

[littlestymaar]

That's technically correct, but irrelevant: you cannot kill yourself with 12 or 20V any more than with 10mV. 120V or 230V is another story.

That being said, it's still very easy not to kill yourself with 120/230V: just shut down the power before touching anything.

[wpietri]

Ah yes, the "move fast and burn your house down" school of "engineering".

[phil21]

Adding a bog-standard breaker and a short conduit run is about as simple as it gets for electric work. It’s rather low risk if you simply read the code and follow it.

If you know nothing about basic electric work or principles, sure - spend the $500 to have an electrician add a 30 or 50A 220V outlet near your electric service panel. Totally reasonable to do as it is indeed dangerous to touch things you don’t understand.

It’s far less complex and less dangerous than adding an EV charge point to your garage which seems to be quite common for this crowd. This is the same (less, since you typically have a lot more flexibility on where to locate the outlet and likely don’t need to pull through walls) complexity as adding a drop for an electric stove.

Where the “home electric hackers” typically tend to get in trouble is doing stuff like adding their own generator connection points and not properly doing interlocks and all that fun stuff.

If you can replace your own light switches and wall receptacles you are just one step away from adding an additional branch circuit. Lots of good learning material out there on the subject these days as well!

[wpietri]

I'm not saying people shouldn't add breakers. I'm saying your talking like people are scaredy-cats and comparing it to working with toys or hello world is exactly the kind of of macho nonsense that leads people to do shoddy engineering.

As a hobby, I restore pinball machines. A modern one is extremely careful about how it uses power, limiting wall current to a small, normally-sealed section of the machine. And even so, it automatically disables the lower-voltage internals the moment you open the coin door. A 1960s machine, by contrast, may not have a ground at all. It may have an unpolarized plug, and it will run wall current all over the place, including the coin door, one of the flippers, and a mess of relays.

In the pinball community, you'll find two basic attitudes toward this. One is people treating electrical safety about as seriously as the people who design the modern machines. The others is people who think anybody who worries about a little wall current are all pussies who don't have the balls to work on anything and should just man up and not worry about a little 120V jolt.

The truth is that most people here are not engineers of any sort. We're software developers. We're used to working in situations where safety and rigor basically don't matter, where you have to just cowboy ahead and try shit. And that's fine, because control-z is right there. I've met people who bring that attitude to household electrical work, and they're fucking dangerous. I know one guy, quite a smart one, who did a lot of his own electrical work based on manliness and arrogance, and once the inspector caught up with him, he immediately pulled the guy's meter and wouldn't let him connect up to the grid again until a real electrician had straightened it all out.

It's true that this stuff is not that hard to learn if you study it. But an architect friend likes to say that the building code is written in blood, meaning that much of it is there because confident dumbasses managed to kill enough people that they had to add a new rule. If people are prepared to learn the rules and appreciate why they're there, I'm all for it. But if they do it coming from a place of proving that they're not "so afraid of residential power", that's a terrible way to approach it.

[matt-p]

To be fair I'd be quite a bit more relaxed working on 120v. Very supprised these machines don't run on dc internally?

[wpietri]

In the older ones, it's almost all AC. One giant transformer, a couple of different voltages. Possibly with "high tap", a way to compensate for wall current with lower than expected voltages. The past is another country.