Tiffany's New York flagship store damaged from an electrical fire...

[JohnRBaker]

While this might now be an engineering disaster, it might prove to be an engineering failure since the the store had recently reopened after a three-year renovation which included replacing virtually all of the electrical wiring and services to the business:

Tiffany's flagship store in Manhattan was ablaze following electrical fire, authorities say

The iconic jewelry store on 57th Street and Fifth Avenue re-opened in April after renovations that took nearly three years. The company touted the store's transformation as the first "holistic renovation" since it opened in 1940.

https://www.nbcnews.com/news/us-new...tore-manhattan-fire-authorities-say-rcna91826

An excerpt from the above item:

The flagship Tiffany store in Manhattan caught fire Thursday morning, according to the New York City Fire Department.

The fire department said they received a report of a transformer fire at 9:38 a.m. and there were no injuries immediately reported.

Con Edison, a New York utility company, was requested to the scene, fire officials said.

The iconic store, made famous in the 1961 Audrey Hepburn film "Breakfast at Tiffany's" stands next to Trump Tower.

I can't wait to see what the tinfoil hat crowd is going to say about this...

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[IRstuff]

https://www.fox5ny.com/news/fire-breaks-out-at-manhattans-tiffany-co-flagship-store

So, all that money spent, but they forgot to replace the transformer? It's unclear if the store was really "ablaze;" that seems like clickbait from the article text, which seems to imply mostly smoke in the rest of the building

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[enginesrus]

Must have been the same transformer from back in 1961?

 

[EdStainless]

Maybe from 1940's.
Power companies don't change transformers until they are forced to.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[waross]

We used to contract for a department store with transformers so old that no-one knew who owned them.
The store was billed as a primary service as the utility could not prove that they owned the transformers.

Wye delta?
They did not realize that one primary fuse had been blown for years on the transformer bank.
As part of the upgrade all three primary fuses were replaced.
("Hey look Charlie. One of the old fuses is blown and no-one ever noticed. I wonder how long that has been there.")
I spent about 15 years learning to hate Wye/delta connections.
I had a transformer burn out in a wye/delta bank as a result of a bad voltage regulator about 10 miles away.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Alistair_Heaton]

i think all our transformers to consumers are delta wye.

 

[SnTMan]

Tinfoil hat crowd? Any ideas about what theories they might advance?

Regards

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[MintJulep]

Wye delta?
They did not realize that one primary fuse had been blown for years on the transformer bank.
As part of the upgrade all three primary fuses were replaced.
("Hey look Charlie. One of the old fuses is blown and no-one ever noticed. I wonder how long that has been there.")
I spent about 15 years learning to hate Wye/delta connections.
I had a transformer burn out in a wye/delta bank as a result of a bad voltage regulator about 10 miles away.

@waross
Could you make a sketch or something to explain this story to us poor mechanical types who don't have a clue?

 

[JohnRBaker]

Before I changed my major to Mechanical, I was a Double-E, and it was because of stuff like wye/delta circuits that I changed majors, not because I didn't understand how they worked or what they were used for, but when entering the Electrical program I was looking for a more 'Electronic' oriented curriculum, having built/modified a bunch of radios while in high school as well as wiring up my own VTVM meter, tube tester and other 'gear' (I loved Heathkit). But when I got to college I realized that at that moment in time (1965) 'Electrical' was dominated by just that, electricity in terms of it's generation and distribution, but not so much as what you could do with it. Perhaps if I had stayed past the middle of my sophomore year, I might have had a better appreciation for all of it, but by then I had had a 'conversion' when I had spent the previous summer working as a mechanical draftsman in an engineering office where the electrical engineers were doing things that didn't really look all that interesting. Besides, my mentor at the office that first summer (I worked for the same company each summer until I graduated) was a Mechanical graduate from the same school I was attending and he influenced my opinion of what the world of Mechanical engineering had to offer.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[waross]

Hi Mint. Are you familiar with open delta circuits?
With two phases and a neutral, you can develop full three phase with an open delta secondary.
If the primary is grounded wye, and one fuse blows, the delta secondary becomes an open delta and still develops full three phase.
But, if the primary is a grounded wye any uneven primary voltages will set up heavy circulating currents in the delta secondary.
It doesn't take much percentage difference on the primary to overload the secondary delta.
One of two things often happen.
1. The circulating current blows a primary fuse and the transformer bank continues working as an open delta.
2. On or more transformers burn up. When one transformer burns up, another may have been so badly damaged that it burns up a few days later.
That is why wye/delta banks are so rare.
My post was sort of an in joke, but technically possible, given my assumption of the age of the building.
By the way, I spent about 15 years in a culture where wye/delta banks were common.
What was also common was that if you looked closely at a wye/delta bank you would see that one fuse was missing and the bank was happily and safely working as an open delta bank.
That is until the next election, but that's another story.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[MintJulep]

"Hi Mint. Are you familiar with open delta circuits?"

Well, 40ish years ago I had to take some basic electrical courses as part of the ME curriculum.

In my professional career I've always had EE's on the team to deal with stuff like this if needed (and it seems rare, so this specific topic was probably never needed).

Typically the dialog goes something like: "Motor. Feed it electricity please."

So, no I'm no longer familiar with open delta circuits, if I ever was.

 

[SnTMan]

JRB, my favorite senior level ME instructor occasionally opened his lecture with the question:

"Why do we study Mechanical Engineering?"

"Electricity & Chemistry"

LOL

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[waross]

Short version:
A grounded wye/delta bank is subject to overheating if the primary phases are not balanced.
If one primary fuse on a grounded wye/delta bank blows, the bank becomes an open delta and continues to supply three phase power.
Open delta banks are not subject to overheating from unbalanced primary voltages.
Many times no-one notices a change in performance.
The blown fuse is most often detected by visual inspection of the primary fuses.

I mentioned elections in Central America being another story.
If the government changed in an election, all higher level government jobs are vacated and filled with favourites of the incoming politicians.
The National Electrical Company would get a new general manager and new supervising engineers.
The new engineers would notice the open fuses and demand that they be replaced.
Line crews would be busy replacing fuses, again and again.
Every time a voltage regulator failed to operate on one phase, fuses would blow in the affected part of the city.
Usually the fuses went, but as the replacement fuses tended to get larger, transformers would start to fail.
Eventually, the new supervisors would back off and things would go back to normal.
One blown fuse at every transformer bank.
Unheard of in North America, common in Central America.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[debodine]

waross thanks for a good example of how politicians often believe that even the laws of physics will bend to their will to achieve a political solution.

 

[waross]

politicians often believe that even the laws of physics will bend to their will to achieve a political solution.

To that end, Can we blame the heat wave in Texas on Biden?
Trump could change the course of a Hurricane with a felt pen.
Why doesn't Biden do something similar for the Texas heat wave? grin (And pi = 3) grin

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[IRstuff]

Perhaps if I had stayed past the middle of my sophomore year, I might have had a better appreciation for all of it,

You're older than me, so that's the big difference; when I got to college, power & electricity was purely elective, and you could have spent your entire 4 years on only electronics. ;-)

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

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[phamENG]

I was looking for a more 'Electronic' oriented curriculum...But when I got to college I realized that at that moment in time (1965) 'Electrical' was dominated by just that, electricity in terms of it's generation and distribution

If only we could have traded places. My first career (Navy) was in generation and distribution, but all of the EE programs around here were electronics based and I had no interest in that. So I left the electrical world for Civil/Structural.

 

[EdStainless]

The best power plant engineer that I ever knew went to Merchant Marine school.
He was an ace at power systems and equipment.

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P.E. Metallurgy, consulting work welcomed