[schlowmo]

This is no powerplant-level story, but sometimes there are high startup currents were you didn't expect them:

On one of my first IT jobs at a big manufacturing company my team was tasked to find out why there are regular power outages in some printer rooms (there were rooms with shared printers on each floor of the office building). There were always some tripped circuit breakers and the facility management had to dispatch someone to put them back on. Between those incidents were always some weeks were nothing happened, but when it happened it affected a lot of printer rooms.

In the end we found a monthly cronjob on a central printing server which triggered a testpage print on all connected printers. Took us quite some time since no one ever saw those test pages. Never underestimate the needed current for a room full of colour laser printers coming to live all at once.

[londons_explore]

Laser printers use a lot of power for a few seconds when coming out of standby.

Part of the printing process involves passing the paper covered in toner through a hot roller, to fuse (melt) the powder toner (ink) onto the page. That roller has to be up to temperature to print. It is normally heated by a powerful (ie. 1 kilowatt) light bulb inside a hollow roller. Sometimes if you peek through the vents in the printer, you can actually see the light it makes.

The light bulb is pulsed on and off to maintain the right temperature - but when coming out of standby it is solidly on for ~10 seconds. Manufacturers want their printers to warm up from standby quickly, so they put very powerful heaters in them, even though the steady state heat requirement isn't awfully much while printing.

[notatoad]

Running a printer off a 2000W gas-powered generator, it always gives me a little chuckle to hit print and hear the engine rev.

[actionfromafar]

Id THAT what that light is?! It always bothered in the back of my mind. It didn’t look very laser-y to me. Especially since the laser was supposed to be infrared.

[dtgriscom]

This is why you never put a laserprinter on a UPS.

[forgotusername6]

In our office we were so over the rated current for the building that after the breaker tripped (which it inevitably did) it wasn't possible to just switch it back on. The moment you did all the servers and PCs went back on and it tripped again. You'd have to go around and pull out plugs all over the office then switch the breaker, then switch them all back on one by one. We also had regular electrical fires. Those were the good old days.

[rootusrootus]

Having enough inrush current to trip a breaker doesn't seem so terrible or entirely unexpected, but electrical fires? That's certainly bad news, the breakers are supposed to be sufficient to protect the wiring.

[Nextgrid]

Most server BIOSes have an option for a random delay on power loss recovery to prevent this exact scenario.

[KeplerBoy]

A single black and white laser printer made the lights in my dorm room dim for a fraction of a second. So yeah, that thing must've pulled quite a few amps.

Also: don't put a laser printer in your bedroom. It's unhealthy. Only learned about that after the fact.

[jstarfish]

> Also: don't put a laser printer in your bedroom. It's unhealthy.

3D printers are even worse, depending on the filament type (ABS is worst?). Always ventilate!

A few papers printed over the course of years won't kill you. What will are the conditions of working adjacent to the office copier, 8-10 hours a day, for years.

Get an air purifier to capture particulates. (Supposedly, houseplants help too.)

[hinkley]

I’ve heard of people hacking system startup procedures so 15 hard drives didn’t try to spin up at the same time.

[h2odragon]

I had a home hacked 1TB+ server, using 5.25in 23GB 8lb monster drives salvaged from a long life as a TV video bank (long, long ago, when dinosaurs walked the earth). There was 60+ actual spindles as i recall.

The drive array was powered by 6x, 400W ATX server supplies with my own wiring harness. This was enough to keep them running but they had to be sequenced carefully to keep from overdrawing the power supplies.

This was all on an UltraSPARC 6k so there was plenty of support for that; bringing up the system always sounded like multiple jet takeoffs tho. Took 15min. When the rack of 10k RPM "quick cache" disks spun up it was like a chorus of the whines of the damned.

[taddevries]

This was a feature on SCSI disk controllers. I remember one controller that had dip switches to set the spin up sequence number, and then you would configure the controller to wait for all the drives to be spinning before it tried to bring the array online.

I'm going from memory here but each Ultra 320 SCSI HDD had a startup current of almost 2 Amps so if you had a disk shelf with 24 drives and stack a few shelves in each rack you could do some serious power damage if you didn't plan the startup sequence right.

[unregistereddev]

On a per-machine basis, many server motherboards have out-of-the-box BIOS support for this feature. At least they used to. It's been a long time since I've built a server and mechanical hard drives are less common than they used to be.

[13of40]

There was some home computer - either an original Apple II or a Commodore PET, I don't remember - where if you splurged for the fancy second disk drive, the computer could be destroyed by a rogue program spinning up both drives at once. And since every program ran at the same protection level as the OS (because there were none), it was either two MOVs or two POKEs to the hardware registers to make it happen.