Magic smoke, lots of it - Page 1
Forum section: electronics / general

author: PeterL
author_rank: Regular Contributor
timestamp: September 02, 2022, 07:57:27 pm
content: Apparently it started with a short in a transformer, after that multiple safety systems failed to cut the power.

author: Gyro
author_rank: Super Contributor
timestamp: September 02, 2022, 08:52:10 pm
content: That's a really impressive sag on those lines!

author: Squarewave
author_rank: Frequent Contributor
timestamp: September 04, 2022, 09:29:22 am
content: Rifa and Hunts could only dream of that....

author: srb1954
author_rank: Super Contributor
timestamp: September 04, 2022, 12:08:50 pm
content: Quote from: Gyro on September 02, 2022, 08:52:10 pmIt would be really scary if your house was under those lines and you saw them drooping nearer and nearer to your house.

author: pcprogrammer
author_rank: Super Contributor
timestamp: September 04, 2022, 12:21:01 pm
content: The text accompanying the video states that a highway (A6) was closed off to allow inspection of the high tension wires. Also all train traffic between the cities Lelystad and Dronten was canceled.It mentions something about a cable breaking being the cause of it all. I do wonder why the cables started to sag? Just expansion due to heat being generated in them or that they got weakened by the heat and that they need replacement.

author: Twoflower
author_rank: Frequent Contributor
timestamp: September 05, 2022, 01:27:46 pm
content: Everything looks better from above:https://twitter.com/iedeklaas/status/1565738694023303168A bit furtherdownis a picture of the damage. To me it looks rather small and local. After seeing the video I expected more molten parts around the fireworks.

author: tom66
author_rank: Super Contributor
timestamp: September 05, 2022, 01:42:29 pm
content: Looks like a fault in the substation caused massive overload of the cables. You can see them smoking as the dust/dirt burns off the wire. (Any transmission experts here, do the cables have any treatment applied or are they bare metal? Maybe the smoke is a varnish burning off?)Always impressive how much energy a system like this can dissipate in a fault condition.

author: bsfeechannel
author_rank: Super Contributor
timestamp: September 05, 2022, 02:09:56 pm
content: Send the video do Big Clive.

author: nctnico
author_rank: Super Contributor
timestamp: September 05, 2022, 03:14:07 pm
content: Quote from: tom66 on September 05, 2022, 01:42:29 pmNote that what is shown in the video are 'only' 150kV sub-grid wires... I do wonder whether the cables are damaged. AFAIK these are steel enforced aluminium cables. I suppose there will be some kind of grease applied to the cables to avoid fretting damage.

author: Vovk_Z
author_rank: Super Contributor
timestamp: September 05, 2022, 07:37:55 pm
content: A smoke from wires could be from a heating dust and some portion of corrosion on a steel part of wires. I'm not sure about any grease applied (I haven't head about any grease applied to those wires).

author: Vovk_Z
author_rank: Super Contributor
timestamp: September 05, 2022, 07:45:58 pm
content: A relay protection at HV lines is usually arrainged that we usually have a main relay protection and about two reserve protection devices (placed at the opposite end of a line and far away) which overlap each other protection zones. So when something like that happens it means not only main protection (or just a HV breaker) malfunction, but there was a malfunction of a reserve protection (or breaker) at the same time.It is always an interesting story to hear what coincidence caused all of this.

author: BradC
author_rank: Super Contributor
timestamp: September 06, 2022, 03:10:52 pm
content: Quote from: nctnico on September 05, 2022, 03:14:07 pmDo have any insight into how do they avoid dissimilar metal corrosion?

author: Vovk_Z
author_rank: Super Contributor
timestamp: September 06, 2022, 10:47:08 pm
content: Aluminum and steel together don't corrode much.

author: nctnico
author_rank: Super Contributor
timestamp: September 06, 2022, 10:59:38 pm
content: In addition: the HV lines sagged so much that they dropped onto the overhead lines of a railroad which then fried all the circuits & switches for that section. Even underground cables that feed the railroad, started to smoke. There will be no trains on that section of raildroad track until next month.