|
homebrew posted:They would have to replace most of the infrastructure above the rail head; including but not limited to feeders, catenary, sub stations, supply lines, switching equipment and control. You would also need to be able to retro-fit the current rolling stock to be able to run on both 1500VDC and 25KVAC to allow operation during the change over. The new rollingstock actually has AC drive. So it gets converted from 66/33kv AC - 1500v DC - then back into AC. I dont know what the motor voltages are though. The north west metro project currently in construction was intended to be 25kva, however the tunnels that have been dug are not big enough for the insulators required for AC. Among other reasons
|
#
?
Mar 17, 2016 11:03
|
|
|
|
| # ? May 9, 2024 12:31 |
|
|
https://www.youtube.com/watch?v=iYupPFZjuJw How could something that can do this get built, and why hasn't anything tripped from the arcing?
|
|
#
?
Mar 26, 2016 02:51
|
|
|
That is some pretty extreme galloping, I'm not sure what could cause that but the slow tripping isn't too surprising. The voltage class looks like its distribution, so its probably only protected by over currents and intercircuit faults tend to have a pretty low operating current value and the intermittency also causes a pretty long delay in tripping time for an OC element.
|
|
#
?
Mar 26, 2016 08:50
|
|
|
Zemyla posted:https://www.youtube.com/watch?v=iYupPFZjuJw Building everything with transmission line clearance for one very specific and rare problem would be cost prohibitive. Although in this case, they may need to set a pole in line to shorten that span. We had this issue on a standard 3 phase line a few years ago and hung crossarms flying midspan to keep the wire separated.
|
|
#
?
Mar 26, 2016 14:49
|
|
|
Is that some sort of a transmission line intersection? Am I seeing it right that they just cross there? Never seen anything like that.
|
|
#
?
Apr 7, 2016 22:26
|
|
|
At work we've had a 66kV GIS circuit breaker fail and blow out the safety valve and doors on the substation. Not sure what's caused it yet. It was pretty well contained so the external damage is pretty underwhelming (just charring and the popped valve) but I can post pics if anyone is interested.
Kim Jong ill fucked around with this message at 02:23 on May 2, 2016 |
|
#
?
Apr 29, 2016 03:28
|
|
|
Kim Jong ill posted:At work we've had a 66kV GIS circuit breaker fail and blow out the safety valve and doors on the substation. Not sure what's caused it yet. It was pretty well contained so the external damage is pretty underwhelming (just charring and the popped valve) but I can post pics if anyone is interested. I have zero experience in any of the subjects involved in this thread, yet I feel I speak for everybody here when I say 
KillHour fucked around with this message at 02:30 on May 2, 2016 |
|
#
?
Apr 29, 2016 06:26
|
|
|
KillHour posted:I have zero experience in any of the subjects involved in this thread, yet I feel I speak for everybody here when I say Yes. Please post pics.
|
|
#
?
Apr 30, 2016 02:02
|
|
|
  As you can see the gear did a pretty good job of containing the arc flash inside the tubing. Kim Jong ill fucked around with this message at 06:37 on May 9, 2016 |
|
#
?
May 2, 2016 02:14
|
|
|
So it arced through the tubing? I would have expected to see stuff blown open, not just charred (again, I know nothing about this stuff). Is that common?
|
|
#
?
May 2, 2016 02:23
|
|
|
KillHour posted:So it arced through the tubing? I would have expected to see stuff blown open, not just charred (again, I know nothing about this stuff). Is that common? Yes, all live components are contained inside the tubing. If you look at the first image you can see the safety valve blown open, the undamaged one is on the left behind the black flap and the blown one on the right.
|
|
#
?
May 2, 2016 02:32
|
|
|
I don't know why I find the derpy little potato-head smiley face in the second picture so hilarious!
|
|
#
?
May 3, 2016 00:44
|
|
|
https://twitter.com/IslesofErin/status/757364207859986432
|
|
#
?
Jul 26, 2016 21:35
|
|
|
i just kept thinking poo poo, it's not good for her to be driving while loving around with her phone goddamn you usa
|
|
#
?
Jul 26, 2016 21:49
|
|
|
Two Finger posted:i just kept thinking poo poo, it's not good for her to be driving while loving around with her phone The passenger is filming. Drivers in the US are on the left side of the car.
|
|
#
?
Jul 31, 2016 01:25
|
|
|
Goddamn Siemens relays and their DIGSI configuration software are the absolute loving worst. 
|
|
#
?
Aug 31, 2016 19:19
|
|
|
Use SEL. Reasons to use SEL: 1. Good price point 2. Outstanding reliability and warranty 3. Modular design and flexibility 4. Powerful programming, networking, and security features 5-Infinity. GE Multilins are garbage Seriously. We had a Mutlilin transformer differential relay crap itself. Not good!
|
|
#
?
Sep 1, 2016 23:34
|
|
|
Yeah I'm mostly speaking from a tester's perspective. SELs are king, Multilins are annoying but ultimately not all too bad, SEPAMs are clunky pieces of junk, and Siemens are a loving nightmare. I've somehow never had to test a multiprocessor Beckwith or Basler yet, but afaik they're not too terrible. It took me two and a half days to test 12 Siemens relays that are only using 50/51 and 27, which would've taken me maybe half a day at most if it weren't for DIGSI being a byzantine piece of poo poo. And yeah, Multilins seem to have way more failures than any other relay type. There was a quiet to-do a couple years ago when it turned out that some of their feeder protection relays reset themselves to default settings if they saw a particular kind of fault. Noctone fucked around with this message at 01:17 on Sep 2, 2016 |
|
#
?
Sep 2, 2016 01:14
|
|
|
Now that's a pretty top-shelf failure. Wow. Are there any details on that problem and fixes for that problem? I need to make sure the guys at work know that is a thing. One of the things we're starting to look at with out SELs is utilizing the IRIG-B GPS inputs to give us extremely accurate times stamps for events.
|
|
#
?
Sep 2, 2016 11:12
|
|
|
It has always bothered me that my car has a GPS receiver that knows the time to the nanosecond, yet is unable to share this information with the clock the car shows me.
|
|
#
?
Sep 2, 2016 11:17
|
|
|
Some people (incl. myself) like to set their car's clock a couple of minutes fast because reasons. real answer: lazy systems design because each separate thing (nav, clock) are seperate devices from separate manufacturing contractors, usually being off the shelf, ancient solutions that are then modified lightly for a specific car manufacturer
|
|
#
?
Sep 2, 2016 14:29
|
|
|
Noctone posted:Yeah I'm mostly speaking from a tester's perspective. SELs are king, Multilins are annoying but ultimately not all too bad, SEPAMs are clunky pieces of junk, and Siemens are a loving nightmare. I've somehow never had to test a multiprocessor Beckwith or Basler yet, but afaik they're not too terrible. Have you stumbled across any ERL Phase relays (they make the Tesla fault recorders)? I don't see them to often and have generally liked their settings interface and would be curious to know if they are easy enough to test.
|
|
#
?
Sep 2, 2016 16:03
|
|
|
Platystemon posted:It has always bothered me that my car has a GPS receiver that knows the time to the nanosecond, yet is unable to share this information with the clock the car shows me. I could write a two page rant on how bass ackwards the GPS time/date signal is. God, gently caress that standard and whatever idiot thought it made sense. (cliffs: Rather than having a year/month/day/hour/minute/second setup, it has a second-of-week counter that goes from 0 to 604799 and a week counter that goes from 0 to 1023, then restarts at 0. The GPS "epoch" is Jan 6 1980. There is no epoch-rollover indicator, so you have to LITERALLY GUESS which GPS epoch you are in based off of the rough number of leap-seconds in the leap-second field and how far into the current epoch you are. It's loving stupid, it's like the year 2000 and year 2038 bugs, but even more stupid, wrongheaded, and shortsighted. We're currently in the second GPS epoch, which started in August 1999.) Setting a clock from the GPS second-of-week is trivial - if you know what timezone you're in and in some cases, whether your county observes DST. Setting the date from GPS is somewhat less trivial.
|
|
#
?
Sep 2, 2016 17:51
|
|
|
Three-Phase posted:Now that's a pretty top-shelf failure. Wow. Are there any details on that problem and fixes for that problem? I need to make sure the guys at work know that is a thing. And yeah, been seeing a lot more implementation of IRIG lately, even outside of line protection relays where time sync is an absolute necessity. freezepops posted:Have you stumbled across any ERL Phase relays (they make the Tesla fault recorders)? I don't see them to often and have generally liked their settings interface and would be curious to know if they are easy enough to test. Never heard of them, actually.
|
|
#
?
Sep 2, 2016 18:28
|
|
|
kastein posted:I could write a two page rant on how bass ackwards the GPS time/date signal is. God, gently caress that standard and whatever idiot thought it made sense.  Somehow I've never come across this even while nerding out on GPS and time-related subjects. Here's a decent quick read on the topic for anyone else wanting to know more: http://www.colorado.edu/geography/gcraft/notes/gps/gpseow.htm *sets a calendar reminder to buy popcorn for April 7, 2019* quote:Setting a clock from the GPS second-of-week is trivial - if you know what timezone you're in and in some cases, whether your county observes DST.
|
|
#
?
Sep 2, 2016 19:37
|
|
|
Yeah. Indiana's the worst offender in the US... but then there are places like India where they have fractional timezones arranged on quarter hours. Who the gently caress thought that was a good idea? Anyways, this isn't exactly related to industrial electrical infrastructure, so I'll gladly stop spergin' about it if it's annoying anyone.
|
|
#
?
Sep 2, 2016 19:50
|
|
|
Is the frequency of the grid still adjusted at night to ensure a correct daily average for clocks that use the 60 Hz (or 50 Hz) signal as a reference? Timekeeping seems pretty related to industrial electricity.
|
|
#
?
Sep 2, 2016 20:26
|
|
|
Guy Axlerod posted:Is the frequency of the grid still adjusted at night to ensure a correct daily average for clocks that use the 60 Hz (or 50 Hz) signal as a reference? Timekeeping seems pretty related to industrial electricity. quote:Today, AC-power network operators regulate the daily average frequency so that clocks stay within a few seconds of correct time. In practice the nominal frequency is raised or lowered by a specific percentage to maintain synchronization. Over the course of a day, the average frequency is maintained at the nominal value within a few hundred parts per million. In the synchronous grid of Continental Europe, the deviation between network phase time and UTC (based on International Atomic Time) is calculated at 08:00 each day in a control center in Switzerland. The target frequency is then adjusted by up to ±0.01 Hz (±0.02%) from 50 Hz as needed, to ensure a long-term frequency average of exactly 50 Hz × 60 sec × 60 min × 24 hours = 4,320,000 cycles per day. In North America, whenever the error exceeds 10 seconds for the east, 3 seconds for Texas, or 2 seconds for the west, a correction of ±0.02 Hz (0.033%) is applied. Time error corrections start and end either on the hour or on the half-hour.
|
|
#
?
Sep 3, 2016 00:08
|
|
|
kastein posted:Setting a clock from the GPS second-of-week is trivial - if you know what timezone you're in and in some cases, whether your county observes DST. Setting the date from GPS is somewhat less trivial. There’s a service menu I can pull up on the navigation system that shows the correct time in human‐readable format. I think in UTC, but it’s been a while since I pulled it up so perhaps not. So the navigation system’s programmers already took care of that. Guy Axlerod posted:Is the frequency of the grid still adjusted at night to ensure a correct daily average for clocks that use the 60 Hz (or 50 Hz) signal as a reference? Timekeeping seems pretty related to industrial electricity. Not at night, but yes, at least for most grids. The Western Interconnection did a study a few year ago about “how much poo poo will break if we stop making time corrections?”. They’re back to correcting, but only when grid time drifts ±30 seconds from true time (used to be ±2 seconds).
|
|
#
?
Sep 3, 2016 00:58
|
|
|
I do have a question that came up recently - some companies are selling synchronous condensers - basically super-overexcited synchronous motors with no attached load. Does anyone know how far you can overexcite those kinds of synchronous condensers? I was discussing it with someone and they were talking about absolutely huge power factors like 0.2 leading but I'm not sure if that's correct. Plus my understanding is there can be overvoltage and stability issues with running part of a grid at a highly leading power factor.
|
|
#
?
Sep 3, 2016 03:17
|
|
|
So I got into an apprenticeship program with a local power company working at a newly constructed natural gas peaker. Going from winding motors to this is probably going to be a big jump. Still damned excited! I'll try to finally dump winding pictures in here. Seems like whenever I start taking pictures I gently caress something up.
|
|
#
?
Oct 5, 2016 02:53
|
|
|
|
|
#
?
Oct 25, 2016 02:39
|
|
|
Im an industrial automation/electrical engineer and I had my tools stolen. I need to rebuy everything. I use my tools for commissioning, the electricians do the actual installation so I don't need anything exciting. My main tools are a 9in1 screwdriver for opening panels, a pair of knipex pliers for adjusting instruments, and a terminal screwdriver. I do need a multimeter, and was wondering if anyone has suggestions or seen cool things. I want something that can read 4-20ma via clampon reliably, continuity, and AC/DC volts. Ive seen the fluke 771, but its $1k, and only does 4-20, which means I would get to carry to meters. They make a 773 which has more functions, but nothing AC. I ordered one of https://www.amazon.ca/dp/B01DZS6VUQ/ref=cm_cr_ryp_prd_ttl_sol_0 because its cheap and small, but wondering if anyone else had ideas.
|
|
#
?
Oct 27, 2016 16:43
|
|
|
Dunno if other models have the same equivalents, or if this one has what you need, but apparently you can get greymarket Flukes on the cheap by buying from foreign markets: https://www.youtube.com/watch?v=XDm5BfRrAsg Edit: Just throwing it out there -- the only use I have for a multimeter is low-voltage DC (e.g. cars, computer PSUs, and the occasional residential thermostat), so I'm a bit out of my depth here. Guy Axlerod posted:Is the frequency of the grid still adjusted at night to ensure a correct daily average for clocks that use the 60 Hz (or 50 Hz) signal as a reference? Timekeeping seems pretty related to industrial electricity.   )I have one of these that runs off line frequency (bought at a thrift store):  I gutted it and put in a modern AA movement to make it a functional clock to put over the fireplace, because that poo poo is noisy as gently caress -- it's a constant-speed motor and one hell of a gear train to slow it down. Actually, now that I think about it, my late grandmother owned a wall clock that made the same noise and looked like something you'd see in a Soviet submarine, I should ask my mom if I can have it, it'd look cool in the living room. (Granny had it in the bedroom, it always kept me awake when I stayed over at her house when I was little.) Chillbro Baggins fucked around with this message at 03:20 on Oct 28, 2016 |
|
#
?
Oct 28, 2016 02:59
|
|
Bad Angus! Bad!
|
This an awesome thread. I'm a wireman and I don't see much industrial out of the controls work side. I find this all super interesting. Just want to say thanks.
|
|
#
?
Oct 28, 2016 06:12
|
|
|
Delivery McGee posted:Do enough people still use those clocks to make it worth the effort? What else is there that's dependent on the line frequency? (In the US, specifically -- I wouldn't be surprised if PAL gaming consoles/TVs still base the system clock on the line freq, because The problem isn’t the old punch clocks you know about; it’s all the old equipment tucked away somewhere that you don’t. Equipment was designed with the expectation that the power grid would keep them within thirty seconds of GMT forever. That wasn’t an unreasonable assumption at the time. Before TCP/IP, before GPS, before cheap, accurate quartz timers, the powergrid was by far the best option for timekeeping.
|
|
#
?
Oct 28, 2016 06:31
|
|
|
New 3 phase underground tap feeding 12470Y/7200 --- 480Y/277 pad mounted 500 kVA transformer. Had to have most of the primary conduit directional bored because part of it went under an in-use shipping dock at a very active chicken egg producer (over 2 million eggs per day). This is power for a new 500'x300' (I'm guessing on size) refrigerated storage and shipping building. So anyway the concrete transformer pad, secondary conduit and wire are provided by the customer, everything else is installed by us and we terminate everything that's in our equipment.  On the left is the primary cabinet, H1a,2a,3a bushings have the primary wire terminated in load break elbows which provide an electrical connection that we can manipulate with hot line tools. H1b,2b,3b bushings have 10kv lightning arresters installed. At the top of the primary cabinet are the bayonet fuse holders. These are fuses that separate the primary windings from the bus that goes between the high voltage bushings. Even a single phase transformer that you would see in a subdivision is set up this way, so that if the transformer has an internal fault or there is a fault on one of the secondary services, the winding will be cleared from the bus, and the primary wire that feeds through (and down the street) can continue to stay hot and minimize the outage.  Secondary cabinet. The round black things around the X1,2,3 bushings are current transformers (CT's) that we use for metering.  Close up of our potential transformers (PT's). Strictly speaking these are not necessary, but they drop the voltage down so we don't have 480v in the meter base, which is a lot safer. I didn't get a picture of the meter base, but it's where you see all my metering wires exit to the right. Standard 13 terminal 3-phase base with knife blade switches and CT shorting blocks. Anyhow I hope you find my wiring to be clean and done in a workmanship-like manner.  Underground is just about the most boring thing I do, but it makes for the most concise pictures. Remove the L for full size. angryrobots fucked around with this message at 01:42 on Oct 29, 2016 |
|
#
?
Oct 29, 2016 01:28
|
|
|
Kinda confused why you didn't just use crimp lugs on the low side cables and save yourself a bunch of hardware.
|
|
#
?
Oct 29, 2016 02:25
|
|
|
If you have any questions that relate to use of odd hardware, you can guarantee that it's because we use material provided for the job by our warehouse manager. Also as I recall, they don't like us using crimp style terminals with only one bolt, and the terminals (that we have) with 2 bolts don't line up with the holes in the transformer's secondary bar.
|
|
#
?
Oct 29, 2016 02:35
|
|
|
|
| # ? May 9, 2024 12:31 |
|
|
Platystemon posted:The problem isn’t the old punch clocks you know about; it’s all the old equipment tucked away somewhere that you don’t. My father spent thirty years in fossil fuel plants for the local utility; It was a big deal for the plant to not be between 59.98 and 60.02hz, even if it was just a transitory event. Most of the fossil plants aim (and hold steady at) for 59.998hz.
|
|
#
?
Oct 29, 2016 02:44
|
|
