In a video from a few years ago, Sarah went thru the process of powering up the 3rd floor of the museum. Well, some things have changed since then, so here's another power-up video for you :)
"First thing that happens is you get an alarm" I think that's just a summary of telecom equipment, in general. First thing it does is panic, second thing is does is realize it's not supposed to panic. ......like cats.
Cmdr La Forge: "If we reroute the power through the interlock converters, we may just be able to go to warp 9." Cmdr Worf: "Power is dropping!" Cpt Picard: "Yellow alert! - Increase power!" Cmdr La Forge: " We are maxing out the converters, temperature is rising to critical levels! " Cmdr Worf: "Compensating!" Cmdr La Forge: "Levels are still rising!" Cmdr Riker: "Any suggestions?" Cmdr La Forge: "If we can insert the correct amount of technobabbel, we might be able to redistribute power!" Cmdr Data: "By rerouting the power, we caused a feedback timeloop. It seems to have created a tiny warp bubble that destabilizes the nacelles. However I believe I can use positronic power to neutralize the field!" Cpt Picard: "Make it so!" [Cmdr Data typing in the necessary commands 5x as fast as a human on his keypad] Cmdr La Forge: "Levels are stabilizing - the energy is rerouted, warp 1, warp 8.2, warp 8,5, warp 8.7 - warp 9!" Cmdr: Worf: "Temperatures are normalizing, we have a stable field! Cpt Picard [adjusting his Star Fleet uniform]: Very well - cancel Yellow Alert! - Number One - Can you please send a message to the chromulans, that we are on our way?" Cpt Riker: "Aye, Sir!". Cmdr Data: "Estimated arrival time would be three hours, 46 minutes and 25.8 seconds at warp 9"
This reminds me of when I used to run a theatre. It was when I was between 15-17 years old. I was bullied and nobody knew what cool stuff I was doing. I was afraid of the darkness in the theatre, but the only way to turn on the lights was to walk across the public space, walk up the stairs, find a small gap in curtains and walk thru that. Everything in pitch black! Then walk a bit to the left to find the right buttons. Ahh light! 😊 Now I’m not afraid of darkness anymore. 😁 Oh and say Hi to Claire from me ☺️
1:03 ... I was about to comment on how cool the knife switch is... but then I saw what looks like the biggest cartridge fuses I've ever seen in my life.
We trusted the engineers on an Upgrade. After warning "Smoke Test" we powered on the Emergency Power Backup Unit. It smoked and took everything else with it. 🙂
As I have an electronics background, having to thump that DC-DC converter several times...made me uneasy. If I was a few thousand miles closer, I would readily volunteer to fix that. I enjoyed the video very much.
Percussive maintenance is my favorite. The switches for 8 of 8 look like ones that were in an old barn on my family's dairy farm, part of knob and tube wiring. The bakelite handles, brass shroud with a window to a disc that displayed on/off text sectors and porcelain base.
Watching this I remember testing number 3ESS systems before we shipped them in the late 70’s at the Northern Illinois Works in Lisle Illinois. I can remember the sound of the relays, hum of the converters and the clakkity clack of the teletype machines just like it happened yesterday.😊Thanks for the memories!❤
This is on my list of places to visit when I eventually can make a trip to the USA. Hello from the UK (London). Also I have much jealousy towards the archive desk (i'm a historian, help me) and it's the perfect cross between old whimsy (with that lamp) and the realities of modern research (the yellow imac). I need a fancy lamp.
Awesome! A lot more complex than the museum in Maine - essentially it’s turn the lights on during the operating season and the switches are only powered on and off and the beginning and end of the season. I really want to come out there and tour your museum 😊
4:46 - There's something about the sound of motors and relays rhythmically whirring and clicking in the background once everything's up that's almost reminiscent of the original NCC-1701 Enterprise bridge soundscape. Have you ever considered making a 10 hours of museum background ambient noise video for people to sleep, read or relax to?
And there’s something about the bridge of the original Enterprise and her main computer that’s reminiscent of a crossbar office. The blinkenlights at the bridge stations are like the indicators on a test frame, and the clunkity-clacking of the computer while it’s processing is like the sound of a #5 marker.
I really enjoyed my visit last weekend, this was definitely a highlight of my visit to Seattle. It was nice meeting you, Sarah. Also, I would love to see a video of that cool orthicon camera. Hopefully they got it running. I can't wait to come back!
This is just so freaking awesome. My inner child is jumping up and down. Watching this, I can’t help but think of that part in Jurassic Park where they turn the power back on. And I just remembered right after that there’s the part where he says “Mr. Hammond the phones are working”, which is very appropriate for your video!
Quite a "turn on!" Love those knife switches and humungous fuses! And for sure, the first troubleshooting action on the flowchart is to give the recalcitrant item a whack.
It doesn't seem so many years ago that I was one of those whose job it was to ensure that you had dial tone when and where you needed it. I did not work in the CO but sometimes had cause to visit it while chasing electrical bugaboos. Much of your museum is comfortably familiar to me. Seems to me that it should still be serving customers. No doubt it COULD.
Saved the most important for last: COFFEE! (Immediately thought of Jeremy Piven’s character from PCU where he shouts half asleep “coffee! Coffee now!!!”) 😅
A nice touch that the voiceover continues in the sped-up sections. (Cute sound effect, too.) I plan to come and visit this summer. Any chance of witnessing this, or even (gasp!) throwing one of the switches?
Haha so much fun with the sfx i love it :) And percussive maintenance as well, that was a nice bonus at the start :) *work* *damn* *it* yeah there we go :) ❤
"Achtung! Alles touristen und Non-technischen Lookens Peepers..." Nice! Makes the Keritech Electronics Super-Combobulator 9000 so simple in comparison, haha! I see a huge potential for automating the power up and down sequence with a bunch of ESP modules and relays here and there... Oh, and fix that cold joint! Keri on, sweethearts :)
I would think that since this equipment is designed to run 24/7, that shutting it down and turning it back on would result in electrical and thermal shock on the components enough to justify leaving it on. That said, I imagine the electric bill is atrocious and the 100% functionality of the equipment is secondary to the mission.
I just love watching these videos my dad was with AT&T Northwestern Bell for 40 years and he's taking me down to the central office and I loved it I've got several of his items he had when he was a lineman too his Billy Goat and his helmet
Since these switches were never really designed to be turned off and on, does that power cycle sequencing add to the gremlins in the machines? I know it’s to save money/electricity. What’s the total power draw when everything is powered on?
What's the total 48v drain for all that gear in amps? Any idea? What's the monthly power bill for running a nominal 8 hours/day when you are all there at work? When I worked for a telco, I used to marvel at the reduction in footprint and power drain for each evolution of equipment (SXS, electronic, digital, VOIP).
I’m one of the volunteers at the museum. IIRC it’s about 100 amps draw. We’re only regularly fully powered up on Sundays. No idea about the electric bill, I’ve never seen one
The walking sound.... Heh.... Reminds me of Hanna Barbera cartoons. Would you consider some light automation so that it can be one-button started? A few networked arduinos and contactors to get the lights on, start each of the systems in sequence.... Could also rubber-mallet the inverter that needs a bop.
I had a friend who was a COT in Arizona. She wore steel toe boots because there was one frame, possibly a Stage 1??, that she would have to kick every once in a while to get it working again.
How often do you power (turn) down the equipment? Most of the equipment I've worked on in the last 5 decades really preferred to run continuously. Always love your videos and hope to visit someday ❤
Nice of you to post this employee training video. 🙂 You forgot to mention powering on the coffee pot *first*. And will you be leaving all the DMS-10 supplies lit continuously?
Oregon State electrician. I'd love to see the museum one day. I'm not sure the wiring systems are NEC compliant. The Bell system must have had a work-around to bypass state inspections 🤔. Very cool, though.
That's a lot of switches! I think the fuses for the crossbar motors are more elegant since they prevent user-error. Also, what would happen in there was a power-outage? Is there a switch somewhere that latches only when power is on, so when power come back the crossbars aren't simultaneously powered with DC and AC?
So at 4:03 you can see exactly what you're asking about, Sarah notices that when the AC was turned on there wasn't a pronounced click from the motor. Inside the motor there's a solenoid that is powered off of the AC incoming power, and what that does is it holds the brushes off the commutator to prevent the motor running on DC *while* the ac is on, preventing it from running on both AC & DC at the same time. And then when power fails, the solenoid falls down and the brushes make contact on the commutator and it becomes a fully DC brushed motor again. If you watch this video you can visualize what im talking about if this doesn't quite make sense. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-uXOyXTevtT0.html
The switches were a museum addition. These motors were meant to run continuously, and the fuse holders were not designed for thousands of insertions over the years. So to preserve the fuse boxes, switches were put in. Alas, without interlocks. But it’s okay. I’ve done this procedure thousands of times, so it’s pretty unlikely that I’ll suddenly make a mistake and not realize it. Worst case is a blown fuse which is replaceable. The motors are pretty clever. When the AC power comes back, the DC brushes are lifted off the commutator by an internal relay and some springs. So the motor can’t simultaneously run on both.
@@ConnectionsMuseum That's really weird, I did this exact explanation an hour before you did but it cant be seen if I'm not on the account that posted it.... I wonder if it got held for review because I linked the Panel motor rebuild video. Hmmm.
When they "lose power", it'll just be the AC. The motors are designed to run off DC when AC is unavailable, and switch to AC when it is. Power restoration would be exactly like this power-on procedure. If you lost both, then DC would need to be restored first. (trying to start with AC would likely pop fuses.)
Wow, didn't realize all the motors for the crossbar switches worked like turning on a Hammond organ, where they're a synchronous single-phase AC motor that you need to use a DC motor to start or it just buzzes angrily and blows the fuse. You can probably turn the DC start switch off once things are rolling to save power but if it's worked this way for most of a century it's probably the right way to leave DC on.
@@ConnectionsMuseumAh, clever! Seems weird they went with a physical switch, then, although I guess it doesn't really matter when these things usually have uptime measured in years
This video has left me with so many questions: 1) Does the museums 48 volt supply share the same supply as the live and active exchange on the floor below. Any risk of a mistake in the museum affecting the live exchange on the floor below. 2) At 0:20, what are all those other big switches for? Some look like they were already on. 3) Are there any systems you leave on 24/7? i.e. The DMS10 4) Why are the motors DC and AC? What's the role of each? 5) Do you ever get failures caused by frequent switching on and off for things that were designed to be left on 24/7?
I can answer #1... Yes, their 48V plant is from the live CO. No, there is no way they could "brown out" the CO. (I've seen a wrench dropped into a PDU. Nothing in the rest of the CO noticed. Power log shows a spike, but no voltage drop. It obviously popped the link to that PDU.)
There's isn't DC and AC motors, there's one motor that can run on both only start on the DC windings. The DC power starts the motor and runs off of batteries in the events of mains failure. A lot of AC motors, especially single-phase, are not self-starting. See page 28 of this great monograph: dougkerr.net/Pumpkin/articles/Panel_Dial.pdf
4) The motors primarily run on AC because if they were primarily DC the brushes would wear out in an unacceptably short period of time and cause the motor to stop. The DC side exists because if utility power is lost the switch needs to continue operating, and the batteries can only supply DC. The DC side is also used for starting, though ideally the motors would only ever need to be started once.
What if I brought all my friends one morning, and we all took a station, and turned everything on in sequence while reading it out like a rocket launch
How much power does all that draw? I was in Bletchley Park a couple years ago and they only ran some of the museum for when visitors were there and only for a couple mins due to funding.
The whole museum (both floors) draws about 80 amps at idle (about 3,840 watts) and peaks at 160 amps at full load (7,700 watts). That is pretty tiny compared to what these machines did back when they were in full service. Easily 2,000A (96 kW) during busy hour. Sometimes much more.
@@ConnectionsMuseum Sometimes WAY more. I'll have to dig up the picture I have of the main disconnect at the BTI Raleigh (NC) CO showing ~400A (480VAC) and that was only one phase. But that was much more gear (5ESS, 600E, frame switches, atm switch, muxes, digital crossconnectes, and the rack of ISP gear.)
Are there any videos of what appears to be a the large motor-generator set seen @1:30 (which you are leaning on) being powered up? So much kneeling and bending to reach power switches. I must be getting too durrrrrned old..... ;)
@@ConnectionsMuseum Magic smoke is hard enough to replace in any device, but I’d imagine smoke for a 3ESS is discontinued and unobtainable. Recall seeing that switch is an ornery cuss to turn on. Have you been able to make it less awful? Or is it more often just “…and we have a 3ESS over here…” display?
I am puzzled by those motors. DC first, then the AC. But after the AC was on, the DC was NOT switched off. How in the world does that work? Maybe we can have a video on that one. Very interesting.
Designed to run on both, just not at the same time. Some great BSTJs on plant power. Also cover in Engineering in the Bell System, volume 3 as I recall but don't have it or the others handy at the moment.
It was mentioned in a few other videos, but they're universal motors, capable of both DC and AC operation. Those aren't "supposed" to be switches, just fuses, as the DC and AC inputs are meant to be constant. In normal operation, the DC brushes are removed from the motor and they're driven with the AC supply. If there's a power failure, then the brushes drop, allowing the DC supply to continue running the motor. Therefore, it's expected to have AC and DC both live. They have to run on DC first (as I imagine you already know / can guess) because with the way they're designed, they require motion to actually spin with AC current. (Most motors that are not 3-phase AC cannot self-start). Therefore, they *need* to be DC powered first, as the commutator and brushes is an arrangement that can start from a dead stop, and once it's spinning, then AC power can be applied to "release" the DC half if you will, and spin the motor normally.
@@teknikal_domain> "Most motors that are not 3-phase AC cannot self-start" A motor that cannot self-start is the next best thing to useless. Thus, the vast majority of induction motors have some type of self-starter, usually involving a capacitor or a shaded pole. This particular style of motor just happens to use the DC side to start instead.
@@user2C47 Basically any motor that's not 3-phase AC has some form of "extra" self start component, be it shaded poles, start windings... DC power, they almost all need something. I mean that a plain one-phase AC motor cannot self-start without some specific starting mechanism.
What do you do with the digital switches that have a more elaborate bring up procedure? You've said other times it is intended to only be done perhaps once in the switch's life.
@@ConnectionsMuseum too bad you can’t connect them to a ringing machine so the foolish ones would get a nice tingle. Then just by listening for the yelps you’d know what people are trying to touch more often. 😂
