Dr. Garbanzo posted:

I liked it when they did a stack of power upgrades at work and wired the phases backwards for the woodwork rooms. Backwards spinning machinery for days including the table saw

hailthefish posted:

Drape Culture posted:

How much do you need for a fish and chips? Are you drinking it or something?

Drape Culture posted:

How much do you need for a fish and chips? Are you drinking it or something?

spog posted:

https://www.youtube.com/watch?v=642x2Y3Zla0

Three-Phase posted:

https://www.youtube.com/watch?v=Zu9fcLSEums

I'm assuming that the first annunciator that starts flashing is indicating some kind of problem developing with the power grid connection before the control room goes dark.

Three-Phase posted:

https://www.youtube.com/watch?v=Zu9fcLSEums

I'm assuming that the first annunciator that starts flashing is indicating some kind of problem developing with the power grid connection before the control room goes dark.

oohhboy posted:

Every alarm bell going off doesn't seem to be all that useful unless you are looking to wake up the dead.

Say Nothing posted:

Three-Phase posted:

Ooh I'd hate to be the insurance adjuster for that...

GotLag posted:

Substituting a ~20% acetic acid solution with a ~20% acetic acid solution? Scandalous!

Three-Phase posted:

I could easily do a whole thread on alarm management, that's a thing nowadays.

SpaceCadetBob posted:

All this pump chat reminded me of a job I went to a few years back.

An electric fire pump had been installed in a vault below the building’s parking lot. It drew water from an adjacent tank. IIRC the pump was supplied by 480v 3 phase powering a 50 hp motor (could be wrong, definitely not a electrician). The call from the building owner was as follows.

Owner “Hey we had been hearing this low rumbling for the past few hours, and suddenly the whole building shook like a bomb”

Me “Ok? Did it set off your fire system?”

Owner “not that we know of, I think it just blew up, we have the fire dept here and they say we need you to come.”

Turns out the pump had kicked on and sprung a leak on the discharge piping filling the vault with water. The dual sump pumps to keep the pit dry had been probably dead for years since no one had looked in the pit for 7 years!

Anywho so the leak filled the vault up till the pump was completely submerged. Then the boom happened. The electrician told me that the pump had experienced either a phase loss, or phase reversal while under full speed. This caused the motor to shred itself? It was a mess is all I know.

We ended up supplying an entire new pump, motor, and controller; right back into the same old pit. At least it gets looked at more frequently than every 7 years but drat what a dumb place to put an electric motor.

oohhboy posted:

^^^ Tom Scott videos are pretty good and he has done work on other channels. The amount of effort he goes through is pretty drat high as he is always on location, does as heap of takes until he gets it right in a single long shot, like the one where he demonstrates a semi-forgotten 3D TV method on a 2D screen, talking and driving up and down a long musical road. So he can't get "lazy" with info-graphics.

The Lone Badger posted:

4%. 20% would be somewhat unpleasant.

Three-Phase posted:

But the problem is the pump was shut down. None of those alarms make any sense (all of those would be part of a normal shutdown) and will just distract the operators. That sort of mistake is probably the more egregious configuration errors but it happens.

Or you have a screen with some alarm that's flashing, and has been flashing for months because the sensor somewhere in the field is broken and the operators just start ignoring it and nobody has went and fixed it. (In fact in plants a lot of times a very small number of bad sensors, like a number of sensors you can count on your hands, can cause more than 90% of the alarm activation that operators have to deal with.)

Or when something happens that upsets the processes at a plant (like a power plant, oil refinery, water treatment plant) and suddenly the operator has alarms blaring and literally hundreds of different alarms coming into his computer and he has to try and figure out both a "big picture" of what's going on, and find a way to start working through all the different alarms.

It's crazy stuff and has some really serious consequences.

quote:

In the face of growing nationwide concern about alert fatigue, Barbara Drew, the UCSF researcher, set out to quantify the magnitude of the problem. For a full month in early 2013, she and her colleagues electronically tapped into the bedside cardiac alarms in UCSF’s five intensive care units, which monitored an average of 66 patients each day. Mind you, this is just the bedside cardiac monitor, which follows the patient’s EKG, heart rate, blood pressure, respiratory rate, and oxygen saturation. It does not include the IV machine alarms, mechanical ventilator alarms, bed exit alarms, or nurse call bell. Nor does it include any of the alerts in the computer system, such as the Septra overdose alert that Jenny Lucca overlooked.

Drew’s findings were shocking. Every day, the bedside cardiac monitors threw off some 187 audible alerts. No, not 187 audible alerts for all the beds in the five ICUs; 187 alerts were generated by the monitors in each patient’s room, an average of one alarm buzzing or beeping by the bedside every eight minutes. Every day, there were about 15,000 alarms across all the ICU beds. For the entire month, there were 381,560 alarms across the five ICUs. Remember, this is from just one of about a half-dozen systems connected to the patients, each tossing off its own alerts and alarms.

And those are just the audible ones.

If you add the inaudible alerts, those that signal with flashing lights and text-based messages, there were 2,507,822 unique alarms in one month in our ICUs, the overwhelming majority of them false.

...I wanted to see if medicine might learn from other professionals who need to perform their tasks in a swirling, often confusing, high-stakes environment. The aviation industry seemed like a natural place to look, so I spoke to Captain Chesley “Sully” Sullenberger, the famed “Miracle on the Hudson” pilot. “The warnings in cockpits now are prioritized so you don’t get alarm fatigue,” he told me. “We work very hard to avoid false positives because false positives are one of the worst things you could do to any warning system. It just makes people tune them out.” He encouraged me to visit Boeing’s headquarters to see how its cockpit engineers manage the feat of alerting pilots at the right time, in the right way, while avoiding alert fatigue.

I spent a day in Seattle with several of the Boeing engineers and human factors experts responsible for cockpit design in the company’s commercial fleet. “We created this group to look across all the different gauges and indicators and displays and put it together into a common, consistent set of rules,” Bob Myers, chief of the team, told me. “We are responsible for making sure the integration works out.”

I sat inside the dazzling cockpit of a 777 simulator with Myers and Alan Jacobsen, a technical fellow with the flight deck team, as they enumerated the hierarchy of alerts that pilots may see. They are:

An impending stall leads to red lights, a red text message, a voice warning, and activation of the “stick shaker,” meaning that the steering wheel vibrates violently. “The plane is going to fall out of the sky if you don’t do anything,” Myers explained calmly.
Further down the hierarchy are “warnings,” of which there are about 40. These are events that require immediate pilot awareness and rapid action, although they may not threaten the flight path. Believe it or not, an engine fire no longer merits a higher-level warning because it doesn’t affect the flight path. (“Fires in engines are almost nonevents now,” said Myers, because the systems to handle them are so robust.) The conventions for warnings are red lights, text and a voice alarm, but no stick shaker. Impressively, the color red is never used in the cockpit except for high-level warnings — that’s how much thought the industry has given to these standards.
The next level down is a “caution,” and there are about 150 such situations. Cautions require immediate pilot awareness but may not require instant action. Having an engine quit in a multiengine plane generates only a caution (again, my jaw drops when I hear this), since the pilot may or may not have to do something right away, depending on the plane’s altitude. A failure of the air-conditioning system — which ultimately can lead to a loss of cabin pressure — is another caution event. With cautions, the lights and text are amber, and there is only one alert modality, usually visual.
The final level is an “advisory,” like the failure of a hydraulic pump. Since jets are designed with massive redundancy, no action is required, but the pilot does need to know about it, since it might influence the way the landing gear responds late in the flight. Advisories trigger an amber text message — now indented — on the cockpit screen, and no warning light.

For every kind of alert, a checklist automatically pops up on a central screen to help guide the cockpit crew to a solution. The checklists are preprogrammed to match the problems that triggered the alert.

And that’s it...

When I told the Boeing engineers about my world — not only the frequency of computerized medication alerts, but also the ubiquity of alarms in our intensive care units — they were astonished. “Oh, my goodness,” was all Myers could say.

Serak posted:

I wish someone would buy him a shirt that fits him though

Three-Phase posted:

My theory is it's a delta-wye motor starter (starts the motor in this case with 347V across the windings, then switches once it's started to the full 600V) but if the different contact sets are operated at the wrong time you can cause a dead-short.

Papa Emeritus III posted:

Wait. That can actually happen? I thought it was a joke.

Oops.

Learned something new, though!

Serak posted:

I wish someone would buy him a shirt that fits him though

oohhboy posted:

^^^ Tom Scott videos are pretty good and he has done work on other channels. The amount of effort he goes through is pretty drat high as he is always on location, does as heap of takes until he gets it right in a single long shot, like the one where he demonstrates a semi-forgotten 3D TV method on a 2D screen, talking and driving up and down a long musical road. So he can't get "lazy" with info-graphics.

Platystemon posted:

lol if you don’t season with reagent grade glacial acetic acid.

POOL IS CLOSED posted:

Harder to get in small amounts than you might expect.

My bottle, which I use to fumigate beehive equipment, keeps showing up in OSHA areas as my partner tries to helpfully tidy. Right next to actual condiments is not an appropriate storage location for glacial acetic acid.

Collateral Damage posted:

I think he's got one of the more listenable voices of many youtubers. There are plenty others that I have a much harder time listening to even if their content is interesting. (Dave from EEVblog comes to mind)

Volcott posted:

Have you considered putting a big old skull on it?

POOL IS CLOSED posted:

I think skulls are contraindicated as signage here because of the alarming variety of skull themed baking tools we own. I stored it in a mini fridge with some hazard tape on the bottle in the end.

Three-Phase posted:

HDS - that’s interesting! I had never heard of that but I did some searching and did see special motors that were configured for “low voltage start/high voltage run” or “high voltage start/low voltage run”.

POOL IS CLOSED posted:

I think skulls are contraindicated as signage here because of the alarming variety of skull themed baking tools we own. I stored it in a mini fridge with some hazard tape on the bottle in the end.

zakharov posted:

Sorry if this was posted somewhere in the thread but it's an absolute classic

https://www.youtube.com/watch?v=XKZUFu97vus