
Just because it's there doesn't mean you should use it - zdw
http://rachelbythebay.com/w/2020/09/05/wire/
======
orev
These things are handy for devices that use the higher current when fully
operational, but need power for initial setup. In IT, the main thing that
comes to mind are managed PDUs. You want to be able to power up the control
unit to get things like networking configured, and you don’t want to be doing
that while standing in the data center balancing a laptop on your knee. With
this, you can get it setup in the office, then go in and start pulling floor
tiles to get it plugged in to the high Amp plug with all the settings pre-
configured. To be clear, when you’re doing the setup you don’t have any actual
equipment connected to the PDU; you’re just getting power to the unit itself
to get power to the management circuitry.

~~~
stickfigure
Pretty much everyone that owns an RV (in the US) has an adapter that converts
the 14-50P (50 amp!) plug on the RV to a 5-15P that can be plugged into common
household sockets. You can't run the A/C without popping a breaker but it'll
keep the fridge and lights on.

The breaker, not the connector, provides safety.

~~~
Hydraulix989
The breaker is there to protect against faults, not someone intentionally
violating what it is protecting against.

~~~
Reelin
Not true. Breakers are most definitely intended to protect against overcurrent
situations regardless of whether it's user or equipment caused. (For example,
unintentionally plugging 30 amps of kitchen appliances into a single 20 amp
circuit. Don't ask how I know.)

That being said, you should never intentionally rely on a safety feature to
cut you out - they exist as a backup in case you screw up. The 14-50P to 5-15P
adapter referred to by GP is an example of "I know what I'm doing". Just be
sure to double check that you really do.

Edit: Also, consider that if you're in a jurisdiction where it's legal to have
a 15 amp receptacle on a 20 amp circuit (many places in the US unfortunately)
then a cable like this could allow you to draw a sustained current above what
the receptacle is rated for but below what would trip the breaker. That's a
fire hazard.

~~~
rsync
"Edit: Also, consider that if you're in a jurisdiction where it's legal to
have a 15 amp receptacle on a 20 amp circuit"

15amp receptacles sold in the US are 20 amp passthrough.

So it is common practice _and completely reasonable and safe_ to put 15amp
outlet receptacles on a 20amp circuit _because the 15amp receptacle cannot
accept a physical 20amp plug_.

It is NEC Compliant _unless_ the receptacle is the only receptacle in the
20amp circuit - see "210.21 Outlet Devices".

~~~
Reelin
I knew many of them were rated to 20 amps in spite of the form factor but I
didn't realize they _all_ were. TIL.

In that case I guess the cable that triggered the article in the first place
is no more dangerous than (for example) the 8 receptacles in my bedroom, all
on the same circuit (15 amp IIRC). It's a complete non-issue.

Edit: Are the plug and cable guaranteed to be able to handle 20 amps though?
From the pictures in the article, it appears someone spliced a 20 amp
receptacle onto a typical (maybe not even 15 amp?) PC power cord.

------
Lammy
I built one of these to use a surplus APC power distribution unit (basically a
really tall power strip with an ethernet port for monitoring) at my house,
because the PDU has a molded 30 amp 120V locking plug that I didn’t want to
cut off. There’s no 240V or three-phase plugs on the thing, and I’m not
running any more or any different equipment than if I used a more traditional
cheap power strip. It’s really nice to be able to have a tall sturdy PDU
running up the back of my rack instead of that, though!

My adapter is obviously out of spec and I wouldn’t leave such a thing behind
for an unsuspecting future tenant to find, but I don’t think there’s anything
wrong with it in my particular situation. I love Rachel’s posts but I wish
they didn’t have this pervasive air of looking down on the stupid people who
did the horrible-thing-of-the-week :/

e: the PDU and plug in question:
[http://i.imgur.com/sUOzquZ.jpeg](http://i.imgur.com/sUOzquZ.jpeg)

~~~
yjftsjthsd-h
> I love Rachel’s posts but I wish they didn’t have this pervasive air of
> looking down on the stupid people who did the horrible-thing-of-the-week

I generally agree, but some things _are_ over the line, and a fire hazard
feels like a good case.

~~~
errantspark
It's minimally a fire hazard and it's very handy to have when you know what
you're doing.

~~~
Beldin
But it ended up in the hands of someone who didn't. That really makes it a
much bigger problem.

"This is OK if used by persons in the know" is not helping: Rachel
wasn't/isn't in the know. So clearly, people without the proper knowledge can
get their hands on this cable.

~~~
rachelbythebay
So certain are you?

I knew it was probably trouble just from a glance. Knowing this topic would
bring out every single nitpicker, I did the actual research to be doubly-sure
before writing the post.

You might be surprised how much extra shit goes into my posts just to avoid
the inevitable backlash. It's not good enough to have a reasonable amount of
knowledge. You have to go _well beyond_ into the arcane to avoid the sniping
from this crew.

And even then, well, THE ONE shows up time and again.

~~~
delhanty
Is Beldin really nitpicking you?

The way I read Beldin's comment was that it essentially agrees with your post.
And HN's guidelines say:

>Please respond to the strongest plausible interpretation of what someone
says, not a weaker one that's easier to criticize. Assume good faith.

~~~
soneca
I also didn’t read that comment as nitpicking. It wasn’t doubting the author
knowledge about the criticism, it was mentioning that the author was not aware
of the reason of why that was made, was able to have access to it and _could_
have used improperly if she didn’t know any better. But she did.

It is like someone else commented, there are reasonable, ocasional use cases
for this that are safe, but the cable should be locked somewhere with the name
of the person that knows why it was built in it; so it’s not out in the wild
for abuse.

That’s only my perception of course.

------
theamk
Really, worrying about 20 amp in a 15 amp circuit?

If one likes to worry about such things, there are much scarier things:
unswitched extension cords [0]. One 15 amp plug in input, three 15-amp outlets
on outputs. Sold in most stores and used very widely. Nothing illegal about
it. Plugs into 15 amp rated outlet, wire itself is rated for just 13 amps, and
you can pull up to 45 amps in the worst case (like if you plug in three
electric kettles).

[0] [https://www.homedepot.com/p/GE-12-ft-2-Wire-16-Gauge-
Polariz...](https://www.homedepot.com/p/GE-12-ft-2-Wire-16-Gauge-Polarized-
Indoor-Extension-Cord-White-51954/203806535)

~~~
noizejoy
Wouldn’t the breaker trip if you try to suck 45 amps through a 15 or 20 amp
breaker?

~~~
kaetemi
After a minute, I think. Depends on your breaker rating.

20 amps on a 15 amp breaker will take a while to trip. You will have wiring
damage.

~~~
namibj
Over here in Germany we call the breakers Leitungsschutzschalter, which
translates to wiring protection switch. They're specifically sized to protect
the wiring in an overload situation, both gradual overloads and short
circuits.

The main issue is actually with the slightly-less trigger-happy breakers
(class D) needing a sufficiently low resistance on the output to ensure that
the magnetic trigger is both reliably triggered if you short the outlet, yet
reliably not triggered by the current spike allowed from it's class. They
trigger between 10 and 20 times the nominal rating, and 16 A is the typical
circuit choice here. Ensuring that you reliably hit 320 A through a long
circuit isn't the easiest/cheapest thing.

~~~
watermelon0
Class B should be used for home use, and all domestic appliances should not
trigger it.

C/D are more appropriate for industrial use, where wiring and devices are
designed beforehand, and people (ideally) won't just join together extension
cords, and put multiple electric motors on it.

~~~
namibj
C is quite typical for new installations due to the abundance of SMPS's, which
can easily cause issues after a power loss due to the combined inrush current.

But yeah, D is indeed rare, and not typically found in domestic installations.

------
exmadscientist
It's worse than that! That's a NEMA L6-20, not a L5-20. That means whatever's
on the other end is expecting a 240V, 20A source. And you're providing 120V,
15A.

If you're _really_ lucky, it'll start in "safe mode" with a warning light or
message. If you're just lucky, it'll refuse to start at all. If you're
unlucky, it'll run but silently limit its capability, so you don't know about
your ticking time bomb. And if you're _really_ unlucky, the power supply on
the other end is a SMPS which will try to pull down 40 amps....

EDIT: Never mind. The photo appears to be _marked_ L6-20R, but that's an
illusion. It's actually shaped, and if you squint marked, to match an L5-20R,
which is 125V 20A. Carry on....

------
ohazi
I have a short adapter like this for my dual boiler espresso machine. You can
configure the machine to allow both boilers to come on simultaneously, which
brings the machine up to temperature faster, but requires a 20 amp circuit, or
you can configure it to only allow one boiler to be on at a time (alternating
between the two, when necessary), which takes longer to warm up initially, but
allows you to use a 15 amp circuit.

The machine has a 20 amp plug, because it's physically capable of drawing 20
amps. I have a 15 amp circuit, so I took extra care to enable the 15 amp mode
and verify that it was working as intended.

These cables _can_ be okay to use if you understand what you're doing _and are
not violating the rules_. They're obviously not supposed to be used to blindly
ignore the wire or breaker ratings.

It's like using `unsafe` in Rust. You're still absolutely not allowed to
dereference null, even though you might be able to. You're telling the
compiler, "I know you can't verify that what I'm doing is safe, but I promise
that I've checked it, and it's fine." That's the same deal you're making when
you use one of these cables.

------
smiley1437
In the same vein, it was popular around Christmas to use male to male power
cords (known as a suicide cord) to string lights together, they were even
available on Amazon:

[https://www.amazon.com/Dual-Male-12-Gauge-Connection-
Extensi...](https://www.amazon.com/Dual-Male-12-Gauge-Connection-
Extension/dp/B0035Z13FI)

OSHA, anyone?

I get that it solved a problem for someone, but I feel a little uncomfortable
just looking at it...

~~~
esperent
What's the issue with these? They look as safe as any other fuse-less
extension cable to me. As long as you have a fuse somewhere in the circuit,
what's the problem?

~~~
Stratoscope
You plug one end into a hot AC outlet. Now the other end has hot 110-120V AC
on exposed pins. Touch them and you are in for a bad time.

A normal extension cord like we've all used has a plug at one end and a
_socket_ at the other, so you won't get killed by simply mishandling it.

I love this part of the product description:

"It Can Help Protect Your Family And Keep Them Safe"

Right...

Having said that, the longer Product Description With Every Word Capitalized
explains the use case somewhat:

You've lost power and it will be likely be out for quite some time. But you
had the foresight to have a generator and one of these cords. You plug one end
into your generator and the other end into an ordinary wall outlet. Now every
outlet on that circuit will be powered from your generator.

However, your normal fuse or circuit breaker will not protect you from an
overload on that circuit, because you've just hotwired your generator into the
"house" side of the circuit. So, as the description says, you may be able to
power your refrigerator and some lights, but overload the circuit and you may
burn your house down.

Also be sure to turn off that breaker or remove the fuse on that circuit.
Otherwise you will be having some fun when power is restored!

Oh gosh, it gets even better. Check out the reviews on the Amazon listing!

Finally, I would like to thank the parent commenter for asking an honest
question. Perhaps it sounded naive to some, but I appreciate a question like
that, as it gave several of us a chance to explain the issues around this kind
of electrical cord.

~~~
unicodepepper
That brings a lot of needed context to this image I saw a long time ago.

[https://pbs.twimg.com/media/ESHx9kxVAAA9_zi.jpg](https://pbs.twimg.com/media/ESHx9kxVAAA9_zi.jpg)

------
petee
Ideally the plug end would be a 20a plug (one blade horizontal), but often in
commercial/industrial places you'll find 15a outlets on 20a circuits. _If_
used correctly this would be ok.

They're probably made for all the people renting floorsanders from Home Depot
with no way to plug em in.

The scariest adaptors are the ones that dump or fake a ground - and 'cheaters'
should be illegal

~~~
jimmaswell
Wouldn't the -|| 20A design solve this? Why does the circular design here have
to exist too?

~~~
baking
The circular one is a twist-loc that prevents it from disconnecting
accidentally.

The -|| 20A design is great in theory, but you only want to install a
receptacle of that type if it is the only one on the circuit (and I mean only
receptacle, so not even a single duplex) because what would be the point if
you can plug in two devices that both require 20A. I've put these next to a
window to power an air conditioner.

The problem with the twist-loc is that the 15A and 20A designs are not
compatible. You can't plug a 15A device into a 20A outlet, but 15A twist-loc
receptacles are rare. So it is not uncommon to put a 20A plug on a device that
draws much less than 15A if say you don't want someone to unplug your router
by accident.

------
jasonjayr
I've manufactured such a monstrosity for temporary use, because the outlet on
the wall used a 15A outlet (the typical plug you see in the US everywhere) but
used a 20A breaker.There should have been an outlet on the wall that had the
20A outlet (one of the blades is horizontal instead of 2 vertical blades).

I used a length of 10/2 solid core wire to make the converter. I took delivery
of a APC network-switched power bar that used the 30A twist-lock, and it
included it's own pair of 20A breakers. I only plugged 10A (verified using a
built in meter) of equipment into it till we could get a proper installation.

(I should add this device is not being used in eons and hasn't needed to be
used since we've made sure to get the outlets setup right before we get the
equipment!)

~~~
minikites
>the outlet on the wall used a 15A outlet (the typical plug you see in the US
everywhere) but used a 20A breaker.There should have been an outlet on the
wall that had the 20A outlet (one of the blades is horizontal instead of 2
vertical blades).

Then replace the outlet, don't cover up one problem with another.

------
Animats
The connector bears the name WELL-SHIN, and a UL approval number E115330.
Those match and check with the UL database.[1] Well-Shin is a company in
Taiwan. Revenue about US$160 million. The part number, WS-111, is the
connector only, not the cable assembly.[2]

Well-Shin makes cables, connectors, and all the small metal parts for people
assembling cables. Their own line of cables is here.[1] They make some common
cables, and this one isn't on their list. The connectors are.

But it's a moulded cable, at least at the plug end. The wires are connected to
the metal parts and the housing is injection-molded around it. Only the
connector manufacturer can do that. Question: is the twist-lock end also a
molded connector? If it is, WELL-SHIN made this, or the whole thing is
counterfeit. Either way, report it to UL. They track counterfeits.

If it's not a molded connector, someone cut the end off an extension cord and
put that connector on.

[1]
[https://productiq.ulprospector.com/en/profile/28839/elbz.e11...](https://productiq.ulprospector.com/en/profile/28839/elbz.e115330?term=Well%20Shin&page=1)

[2]
[http://www.wellshin.com.tw/en/mod/product](http://www.wellshin.com.tw/en/mod/product)

~~~
Reelin
> If it's not a molded connector, someone cut the end off an extension cord
> and put that connector on.

That's almost certainly what was done. You can buy a loose L5-20R at the local
hardware store. Typical PC power cables are plentiful and cheap, saving you
the trouble of buying and assembling a 5-15P and a length of cable.

------
fiddlerwoaroof
Is this actually unsafe? In theory, won’t the circuit breaker flip if the load
ever becomes unsafe? ISTM, this might end up being inconvenient (Plug another
Computer into the UPS, and the breaker flips), but it won’t be dangerous,
unless someone also “upgraded” the breaker.

~~~
HarryHirsch
_unless someone also “upgraded” the breaker_

That happens. 10 years ago or so there was a big explosion at the University
of Texas, Austin. The Chemistry Department had a storage vessel for liquid
nitrogen. Of course the cold liquid evaporates and creates pressure inside the
container. Typically the internal pressure is held at 1.5 bar by means of an
escape valve. The escape valve failed and someone replaced it with a solid
brass plug. To prevent accidents if the escape valve fails there is also a
burst disk that breaks at higher pressure but before the tank itself explodes.
That mechanism worked as designed, it released pressure, so they replaced the
emergency release valve with a brass plug as well. One nice night the burst
pressure of the tank itself was exceeded, and the bottom launched itself
through the floor. The top was stopped by a concrete beam, but it did break a
few water pipes.

Here's the report from the Fire Marshal:
[https://www.tdi.texas.gov/fire/documents/fmred022206.pdf](https://www.tdi.texas.gov/fire/documents/fmred022206.pdf)

There is no need to test if safety equipment works, because sometimes it does
not.

~~~
c1ccccc1
The terrible thing is that this happened in a chemistry lab, where people
should _really_ know better. Liquid nitrogen is dangerous in a surprisingly
large number of ways: Cold burns when touched, explosions when sealed in a
container. And if you're in an enclosed space with it, you've got to be
careful not to let it fill the room with nitrogen gas and asphyxiate you.

~~~
HarryHirsch
_in a chemistry lab, where people should really know better_

Some places are accident factories, where people are encouraged to be team
players and not rock the boat even in the face of clear and present danger.
Universities can be problematic, when you do your PhD you really need your
supervisor to give you a good recommendation.

------
hyperion2010
I might translate this to "If you don't understand what it's for, don't use it
for what you think it might be for." Things like this exist, and they are
exactly as absurd and dangerous as this, but they aren't for people who don't
know what they are doing, they are for people who know exactly what they are
doing. It is like a booby-trapped burial site where only the priest are
supposed to be able to get in without getting crushed by boulders or impaled
on spikes. Unfortunately most code doesn't come with a sign that says "never
call this function unless you know exactly how many C level executives are
going to be up all night when you do." Engineered safety controls tell you
that some things should be obscure and hard to figure out so that people who
don't know what the are doing don't accidentally destroy something. On the
other hand this prevents knowledge transfer and effective communication, but
if it is not obscure some idiot will set both the `--i-know-what-i-am-doing`
and the `--i-accept-full-legal-resonsbility-for-the-consquences-of-running-
with-this-enabled` flags AND do it in a shell script. This article is spot on,
and I have come to think of people who have developed this mindset as having a
kind of selective lack of curiosity, say, defensive disinterest -- they see a
system that they don't understand, identify that it appears to be dangerous,
leave it bloody well alone, and possibly leave a note telling others to do so
as well. Those in the know hopefully appreciate when the defensively
disinterested warn others off, and as in this thread, take the opportunity to
educate about the potentially not completely insane use cases for such things.

------
alibarber
So I came across something like this once, UK 13A Plug -> 16A Ceeform Socket
in an event and asked the guy (a professional with credentials) about it and
he explained that it was actually fine from a safety standpoint: (This
happened a while ago, might have understood it slightly wrong)

The 13A fuse was there to protect the thing from drawing more than 13A from
the supply. After that it just doesn't matter - under a fault, nothing would
be able to draw more than the lowest rated link. It's up to you to be aware
that if you push it to 11 then things will fizzle out when the fuse goes, but
no damage would be done. In this case it was just a couple of parcans so no
issue.

The dangerous combination would in fact be the opposite, a 32A Ceeform plug to
16A Ceeform socket unfused. Then it would be possible under fault to actually
pass >16A through a thing only rated up to 16A.

He said something along the lines of a 16/32A socket on the wall just means
that the socket is capabale of handling 16A, not actually giving you that (or
if it was even switched on) and in his line of work for anything needing more
than 'a bit' of power they'd rather just tow their own generator in.

This made sense as in the UK, which is different from a lot of the world, 13A
sockets are usually backed by a ring main that will happily give you 32A -
hence a fuse is mandatory by law in all plugs to protect the plug and flex
_leading from the plug to device_ and anything after that. Conversely, you can
buy a cheap car inverter with a 13A socket perfectly legally, but try drawing
that full 13A and see how far you get.

Also note I'm just talking about amperage here, the voltage (i.e. blue ceeform
230V) must be the same throughout.

~~~
gambiting
So I discovered something disturbing about UK plugs - yes, the fuse is 13Amps,
but it's not like your main circuit breaker which trips instantly - no, those
fuses take a _long_ time to melt and break. I discovered this by accidentally
drawing 20 amps through a single plug, because I was mistaken about the power
draw of the two devices that were plugged into one extension cord. I only
realized once I touched the cable and it was pretty hot(not melting yet, but
definitely hotter than you want your cable to be) - I got a power draw meter
and yep, I was drawing about 4.4kW(~20amps) through a plug equipped with a
fully intact 13Amp fuse! I asked an electrician how can that be, and he said
that yep, these fuses won't protect you from a higher draw that lasts a few
minutes, the current needs to be either super high(like, not 20 but 50 amps)
or prelonged enough to melt the fuse.

That has....changed my perception of how these fuses are meant to work.

~~~
nucleardog
A typical breaker won’t blow instantly when you exceed the rated current
either (unless you exceed it by a lot — like at least 5x). At less than double
the rated current you could be waiting several minutes. So it’s not just a UK
fuse issue.

This isn’t really an issue. “Hot enough to concern you” is undesirable but not
really what they’re worried about so much as “hot enough to combust”.

And the alternative—if it were to blow instantly—is that your fuses would blow
any time you turned something on with a high inrush current like a stand mixer
or a vacuum cleaner.

------
c0nsumer
I once worked with a very friendly can-do project manager who did something
very similar.

He had a deployment project that was behind because the cabinet's PDU needed
an L6-30 and the row only had an L6-20. So he went over to Grainger, bought a
L6-20 male connector, an L6-30 female connector, some appropriate cable, and
made an adapter.

If I recall correctly he'd calculated the maximum draw from the cabinet as
right about 20A, so he was really bothered when the facilities manager
absolutely refused to deploy with that adapter. (<cough>inrush?<cough>)

------
qppo
It's not horribly uncommon to see 20A rated breakers connected to standard 3
prong sockets and people to have gear with these connectors.

Interesting sidenote, I can tell you at least one NFL and two college football
stadiums require these cables to use any broadcasting or recording equipment
on the sidelines. And countless venues for live music, usually ones wired
before the millennium.

~~~
bleepblorp
Unless the NEC has changed recently, it's legal in the US to use 20A breakers
(with appropriate wiring e.g. 12ga or larger) to supply 15amp receptacles.

I don't know why the NEC allows this given that the practice is banned in
Canada despite identical circuit breakers, wiring, receptacles, and electrical
devices being used in both countries.

------
mmphosis
_The 30-amp locking receptacle has become the norm at most U.S. and Caribbean
marinas, so equipping your boat with a 30-amp inlet minimizes compatibility
problems._

[https://www.fisheriessupply.com/marinco-
marine-15-amp-125v-t...](https://www.fisheriessupply.com/marinco-
marine-15-amp-125v-twist-lock-male-plug)

------
dehrmann
I remember seeing USB A to A cables. Actually, I just found one on Amazon. The
only reason I know for these to exist is some external HDD enclosures where
the designer somehow understood USB well enough to make a controller board,
but not well enough to know it should have been a B connector.

~~~
jrockway
I had a Wacom tablet that comes with one of these. The tablet's only input is
USB Type C that requires the other side to support the Displayport alternate
mode... and computers didn't really have that kind of port when Wacom released
it. So it same with a box that has a USB type A port, a mini Displayport, and
a USB Type C port. You can then use an A-A cable to plug into your computer
(along with the Displayport for video), and then connect via Type C to the
actual tablet. In theory, you can also connect the box to the tablet via Type
C, and it becomes an extra USB port.

It is janky and every time I go through my cables I say to myself "why on
Earth does this abomination exist", but I suppose they had a good reason. Now
that graphics cards have Type C ports for VR (apparently), it's not a problem.
But it was back when they first came out. They ended up having to use a stupid
special cable because they made their device too nice (if you did have a Type
C port with video out on your computer, you could still use the converter that
you paid for).

I suppose there is some precedent for USB devices that can switch over to
being the host. I remember buying a "USB on the go" adaptor and plugging a
mouse into my Nexus back in the day. It worked! A cursor appeared and you
could move it around.

(Unfortunately, I hated that tablet. My Surface Pro was much better, and it
wasn't even designed for drawing. I gave both devices away and now just use my
iPad, which still isn't as good as the Surface Pro 4.)

~~~
sbx320
> Now that graphics cards have Type C ports for VR (apparently)

Had. The VirtualLink standard (for which the ports were supposed to be used),
was never wildly adopted and is pretty much dead. AMD never introduced Type C
ports and Nvidia removed them from their newer graphics cards as well.

Sadly this also means there's practically no direct support for the
DisplayPort alternate mode on Desktops anymore, assuming you want a dedicated
GPU.

------
other_herbert
This looks like a power cord that would be used for a welder that can run on
120 or 240v usually at about half the capacity when at 1/2 the voltage

Edit: nevermind since it was pointed out that this is only a 120v appliance
end

------
josuepeq
Relying on a breaker to save the day if a device draws too much current from
an adapter such as this is a terrible idea.

My issues with the adapter:

\- The adapter is allowing higher current devices to connect to an outlet
design that only started showing up in the 1960s; connected to “god knows
what.”

Some people use two-to-three prong grounding adapters. (NEMA 1-15 to 5-15.)

Some NEMA 5-15 outlets are wired with bootleg grounds.

My Grandmothers’ old house, built in 1837, was upgraded with “knob-and-tube”
wiring sometime in the 1910s and had NEMA 1-15 plugs. There’s a certain amount
of heat a knob and tube wiring install is designed to allow due to an over
current; but this was contingent upon being installed properly, and never
modified. The issue today (and in the 1950s) is that many DIYers spliced their
safety into a black hole of junction boxes.

Even If it’s a shiny new Siemens Load Center, none of that matters if it
connects to wire made during the Ottoman Empire, and illegally spliced into
the old breaker panel during the 1970s.

\- The breaker box, fuse box, load center.... Well, what is it? It is
important to know who made it, and if it was done correctly.

Fuses take time to blow. There could be 10 other things on that branch and it
could blow quickly. It’s the big unknown. Did the last occupant get tired of
replacing blown 15A fuses because they couldn’t use two kitchen appliances at
once, and drop in a 30A?

Same goes with actual circuit breakers. Square D will gladly sell me a single
30A breaker that fits into the spot where I pulled a 15A breaker from.

I bet Federal Pacific Electric would too if they were still in business
selling StabLok breakers that cheated their way through the UL tests.... in
which their panels are installed commonly throughout the Bay Area. Relying on
a Federal Pacific, Zinsco, Wadsworth panel to trip with the _correct breaker_
is too much a liability for most home insurance companies.

If one prefers to rely on circuit breakers, I’d really suggest that they
reconsider. Especially during Fire Season here in the Bay Area.

Rachel By The Bay knows what she doesn’t know about the branch circuits in her
home. She’s 100% in the right here, as it pertains to her unique situation.
Exercise an abundance of caution and hire an electrician!

------
jaaames
What do you do when you see this lying around?

[http://www.fiftythree.org/etherkiller/img/etherkiller.jpg](http://www.fiftythree.org/etherkiller/img/etherkiller.jpg)

~~~
LargoLasskhyfv
Thinking of _Powerline_ or PoE!

------
shash
I don’t know what you guys are bellyaching about...

[http://www.madamletmetellyouonething.com/wires-jammed-
into-t...](http://www.madamletmetellyouonething.com/wires-jammed-into-the-
socket/)

------
h2odragon
I'd say such things _should_ exist, sometimes, because the job needs to be
done. They should be obvious ugly hacks covered in tape and embarrassing by
their existence, to help prompt someone to find a the proper solution.

Hands up whover made an RJ12 fit an MMJ when wiring up a vt terminal serial
port

~~~
Godel_unicode
It sounds like the job that needs to be done is ensuring you've adequately
planned ahead. With very few exceptions, this is the result of someone trying
not to pay what the job costs and just faking it.

Hands up whoever insists on doing site surveys so they can do quality work
they're proud to put their name on.

~~~
h2odragon
"the show can't go on because the site survey was wrong" won't fly. That's
when you bust out the wirecutters and electrical tape. Preperation is great,
wonderful, etc, etc; and _never complete_. Shit happens, be prepared to deal
with it.

Many disagree with me, but im a happy lunatic.

------
HugoDaniel
Like docker

------
stickfigure
This seems to be written by someone that doesn't understand electrical wiring.
I have (and sometimes use) adapter cables like these (5-15P to L5-20R).

As other people have pointed out, you can draw a lot more than 15 amps through
a 15-amp cable by plugging a simple Y connector into the end. That's why
15-amp circuits have 15-amp breakers in the panel. There are a variety of
devices that _could_ draw 20 amps (and thus have 20 amp NEMA connectors) but
don't necessarily. If everything is wired properly, the worst that happens is
you pop a breaker.

I would be more concerned about the gender-opposite of the connector shown
(ie, L5-20Plug to 5-15Receptacle). That would allow you to plug a 15-amp rated
cable into a circuit which is defended by a 20amp breaker - now the cable is
the weakest link.

TL;DR: She has it backwards.

~~~
scottlamb
> I would be more concerned about the gender-opposite of the connector shown
> (ie, L5-20Plug to 5-15Receptacle). That would allow you to plug a 15-amp
> rated cable into a circuit which is defended by a 20amp breaker - now the
> cable is the weakest link.

Huh? Isn't plugging 15-amp appliances (with cables only rated for that) into
20-amp circuits totally normal? I have a few NEMA 5-20 receptacles in my home;
in fact I think the latest code requires that kitchens have at least two of
them. They accept NEMA 5-15 plugs, and I use them in that fashion without a
second thought. You probably do, too.

My understanding is that the circuit breaker protects the wiring in your wall
from excessive current. If your appliance may draw more current than its cable
can handle, shouldn't it have its own fuse/breaker?

The adapter cable that Rachel mentions allows plugging a 20-amp appliance into
a circuit that may actually have a 20-amp breaker, with this plug between
that's only rated for 15 amps and doesn't have a built-in fuse/breaker. (I
wonder if the cable is at the proper gauge for 20 amps or not.) That doesn't
sound proper to me...

~~~
stickfigure
The problem is when you plug one of these (as someone already linked) into the
20 amp socket:

[https://www.homedepot.com/p/GE-12-ft-2-Wire-16-Gauge-
Polariz...](https://www.homedepot.com/p/GE-12-ft-2-Wire-16-Gauge-Polarized-
Indoor-Extension-Cord-White-51954/203806535)

Everyone in the US has a bunch of these. 16ga is good for 13 amps. Even if
everything is working properly, two 10-amp devices will draw 20 amps and the
cable will melt before the breaker pops. If everything is not working
properly, and there is a short-circuit, the cable will still probably melt
before the breaker pops.

This is why the OP gets it exactly backwards - she is looking at the big
cable/connector and thinking "that's dangerous!" No, danger comes from the
_weakest_ link in the system, not the strongest. That weakest link must be a
fuse or breaker.

------
bartread
This is a pretty ignorant and immature post.

For example, "All I know is, if that was my building and they were my tenant,
I'd probably sic the fire marshal on them." Well, you clearly don't know very
much, and this kind of histrionic commentary isn't useful to anyone.

On the other hand reading the comments I'm pleased to see people chiming in
who do know the purpose and legitimate use cases of this little adapter.
Personally I had no idea so I'm fascinated to learn, and hopefully one day the
knowledge will come in useful. So even though the post has irked me I'm glad
to have read it just because of the comments.

