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Comment by CodiePetersen | Hacker News Reader

Tickling the dragons tail seems very appropriate. I'd be sweating bullets manaually adjusting a nuke core with a screw driver.

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Not to advocate risky behavior, but this doesn't surprise me at all. Experience increases the perception of safety at a rate faster than actual safety. Every place I've worked where you could put yourself, expensive equipment or customer satisfaction in danger to make something easier for yourself people would do it. Deploying straight to prod, doing surgery on live databases, soldering on equipment plugged into mains, servicing a UPS without disconnecting 48V worth of lead acid batteries (that was one HELL of an arc weld).

The corners people will cut never cease to amaze me.

Good old normalization of deviance: https://www.ncbi.nlm.nih.gov/m/pubmed/25742063/

This is why power paper cutters have two widely separated on buttons.

> Experience increases the perception of safety at a rate faster than actual safety.

I learned to drive nine months ago, and I've been watching myself do this every time I get on the highway in the past few months. Even knowing that I'm doing it, it's hard to avoid.

I learned to drive 40 years ago. Watching yourself drive and noticing situations where you're taking unneeded risks is what separates good drivers from mediocre ones. Never assume you can't do better.

> soldering on equipment plugged into mains

o_O!!!!!!!

I've cut a LOT of corners, but that one is just insane...

"But this is the ground wire so it's okay".

Hint: Lots of people have daisy chained outlets backward, and lots of AC circuits still work with the wiring reversed.

Pretty sure we found one where they had reversed them twice, so black was hot at the end of the circuit but not in the middle.

I have no idea why I never considered this possibility. That's terrifying.

I inspected all my outlets after finding out what 60VAC feels like going up one arm and down the other (touched two server cases, one on a grounded outlet, the other floating). I found several suprises: a knob and tube circuit had been "upgraded" to 3-prong faceplates without wiring the ground to _anything_, and some outlets were backwards. You never know if it's the work of a DIY electrician unless you get it checked out.

Someone hooked the washer and dryer into the mains at my Grandma’s house. It was interesting seeing my Dad go from confused to realization to angry without having caused the transition. Getting that fixed was an exercise in careful. As Dad is fond of saying “I’m amazed you thought of it and appalled you actually did it.”

Funnily enough that's a normal practice in the UK/Ireland. In all the places I've lived, washer and dryer are plugged straight into a regular outlet (sometimes with an extension cord if it can't be reached).

Makes me wonder, why not make a 110v washing machine and save the trouble of having both 110v and 220v at home?

Most (all?) washing machines are 120V. Electric dryers rarely are, because they need a lot more power. I had a small washer/dryer combo unit years ago that used 120V, and it took about four hours to dry a load that was about half the size of a normal dryer’s capacity.

Running both voltages into a house isn’t much of a burden. Residential electricity in the US is two-phase. A 120V circuit pulls from one phase, with the various circuits in your house divided between them to even out the load. A 240V circuit just connects to both phases.

110 (120 really) volt washing machines are very common, at least in the US. Dryers, on the other hand, are 240 here.

I get the sense some of these posts are talking about devices connected directly to the building's supply wiring (not to a receptacle downstream of the circuit breaker panel).

In the US all residential washing machines are 110V, as are gas dryers, but electric dryers take 220V.

The US uses split phase 240VAC for residential. 240VAC is really two 120VAC 'hots' 180 degrees out of phase. So 240V between phases, but 120V to ground/neutral.

Industrial 240 usually is single or 3phase.

Well yes, but we usually segment areas into their own circuits and in a well-built residence the laundry appliances get a fused circuit to themselves (or, at the very least, share one with the kitchen sockets). So your amperage/fuse-trip-point is isolated to that one group of sockets.

Plus as you semi-observe, everything on a socket here is 220V

> Someone hooked the washer and dryer into the mains at my Grandma’s house.

Do you mean they wired it in parallel with the main breaker panel, so you couldn't disconnect it to work on it?

Yep. We flipped off all the breakers and the damn washer & dryer were still hot. My memory was a bit off and the the water heater and maybe stove were also hot. We had to replace all of that. I was 10 at the time so I was working on other stuff while Dad and the uncles took care of it. Putting in a new structural support beam was also enlightening.

I ran into that, in an old house.

Some decades ago, the house had two meters. One was just for the hot water heater. But when they removed that one, they just connected the water heater to the main meter. Directly. Not through the breaker panel.

Damn. Almost killed me.

Would have probably killed someone in our group except my Dad and one of my uncles had a bad feeling about it. Apparently working for Ma Bell will give one a sense of those things.

The most common examples are probably driving and smoking.

I used the phrase "tickling the dragon's tail" recently when I ran some maintenance code in production without testing it first (because there really wasn't a way to test it outside of production, long series of failures to get to this point, I know). I used to call it cowboy coding.

FWIW, this was the first time I'd done something like that in about 5 years and I felt horrible during and afterwards even though nothing went wrong. I felt like I should have given up a sobriety coin or something. Feels bad. Like falling off the wagon.

I think it’s a good thing that you feel a bit unsettled. It shows you have the professionalism to know it was a bad plan, but you also had the knowledge to know sometimes a bad plan is the only plan you have. Don’t dwell on it though, that would be unhealthy since you already know the lesson of the experience.

Or remove half of the bolts from top to bottom of a crane (instead of one level at a time) to speed up its deconstruction by a couple of hours?

https://en.wikipedia.org/wiki/Seattle_crane_collapse https://www.seattletimes.com/seattle-news/what-caused-seattl...

Hollywood portrayal: https://www.youtube.com/watch?v=hh89h8FxNhQ

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