Manhattan Partial Blackout 2

[Mbrooke]

Looks like they lost the west 49th st substation. And reports of a manhole fire though Con-Ed says it may not be related. Any information on your side?

 

[Palletjack]

Wow, that’s a lot of information to digest. I’m not going to read through it...
I did look on google, and while I’m not familiar with all the stations and their locations, I did see a couple and saw breakers on the ground. Some had SF6 interrupters, as indicated in your last pictures.

I’m really not familiar with what happened, but here’s a question. Some years back the north had a large power outage. It was started by a tree trimming crew, I believe. They knocked out a feeder, another breaker failed in a station, taking that station out. Stations in parallel now are asked to take on additional load instantaneously. Can’t handle it, causing 50, 51 and 81 relays to open circuits. Something like this prompt this change?

 

[Mbrooke]

To sum it up the West 65th street outage should not have spread (resulted in 5 138kv feeders going down) even if all 5 or 10 transformer protection relays at 65th called for trafos shutting down.

Take a screen pic of those stations, I can immediately tell you what is what.


What prompted circuit switchers being installed at Con Edison area substations was a fire at the Seaport substation in 1990. The transformers could not be shut down without de-energize all 5 138kv supply feeds. Unfortunately when those were de-energized, so was the trade center substation which also takes taps off those 5 feeders.


August 14, 2003 was a bit different. In simple terms several 345kv lines tripped out causing other lines to sag into untrimmed trees also tripping out. The remaining lines began to take on the work of the missing lines, and since more amps = more heat, those lines also sagged and tripped. Voltage in the Ohio area began to fall from all the missing equipment causing generators to shut down. The depressed pocket pulled power from its surroundings causing those to overload and further trip lines and generators. Eventually it triggered a domino effect which spread throughout the North East and Canada.

 

[Mbrooke]

Old thread- but thought I would add this to the archived history. West 65th st in an old Russian Engineering book. Note that are some translation errors and age based discrepancies.

https://translate.googleusercontent...700201&usg=ALkJrhjQYHfEL-m8qnTaQ1HylMmEsetFeQ

https://files.engineering.com/getfi...4d50-ba2c-d1947de66f53&file=Mother_Russia.jpg

 

[Mbrooke]

Much thanks to another member for posting this thread:

https://www.eng-tips.com/viewthread.cfm?qid=467847

From David's link, [highlight #FCE94F]a PDF on what caused the West Side Outage[/highlight]:

https://www.nerc.com/pa/rrm/ea/Less...ansformer_Ground_Differential_Relay_Misop.pdf

Much simpler than I previously assumed- just a few missing wires. I'm relived to be honest.

The 6 transformers on the edge feed the load until the one in the middle needs to carry load to perform maintenance on one of the perimeter transformers.

You were correct, One of the Five is what I call a "hot spare" as mentioned by the NERC PDF regarding the incident.

 

[Mbrooke]

Lastly while this thread is closed:

https://www.eng-tips.com/viewthread.cfm?qid=447707

A PDF on what caused the [highlight #EDD400]Astoria Blue Light event[/highlight]:

https://www.nerc.com/pa/rrm/ea/Less...tected_Fault_in_a_Transmission_Substation.pdf

Sadly, it was not a special at K-Mart like I had originally hoped.

 

[cuky2000]

Mbrooke
Do you know the continuous current rating of the 13 kV breakers I the Con Ed system?
Are any breaker rated greater than 3000A continuous?

 

[Mbrooke]

You ask a really good question.

Honestly, I do not know of each breaker's nameplate ratings. I think their sync bus breakers might be rated over 3000 amps, but I do not know for sure.

 

[sunilbhaiya72]

I agree that it is somewhat pointless in that we do not have all the details on the relaying, but at the same time such a grand failure deserves a conversation. 9apps cartoonhd

 

[Mbrooke]

NERC released a report. It looks like EM relays were involved and missing wires in the CT circuits.


From what I gather it looks like 65th st did not have circuit switchers installed at the time of the incident which would have greatly "contained" the outages. Either that the trip signal spread further than it should have but nothing is mentioned in the NERC report in regards to circuit switchers.